YAL001C S000000001 TFC3 Largest of six subunits of the RNA polymerase III transcription initiation factor complex (TFIIIC); part of the TauB domain of TFIIIC that binds DNA at the BoxB promoter sites of tRNA and similar genes; cooperates with Tfc6p in DNA binding ORF Verified inviable YAL003W S000000003 EFB1 Translation elongation factor 1 beta; stimulates nucleotide exchange to regenerate EF-1 alpha-GTP for the next elongation cycle; part of the EF-1 complex, which facilitates binding of aminoacyl-tRNA to the ribosomal A site ORF Verified inviable YAL025C S000000023 MAK16 Essential nuclear protein, constituent of 66S pre-ribosomal particles; required for normal concentration of free 60S ribosomal subunits; required for maintenance of M1 satellite double-stranded RNA of the L-A virus ORF Verified inviable YAL032C S000000030 PRP45 Ortholog of human transcriptional coactivator SKIP, can activate transcription of a reporter gene; interacts with splicing factors Prp22p and Prp46p ORF Verified inviable YAL033W S000000031 POP5 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends ORF Verified inviable YAL034C-B S000002137 Hypothetical protein ORF Dubious inviable YAL034W-A S000000032 MTW1 Essential component of the MIND kinetochore complex (Mtw1p Including Nnf1p-Nsl1p-Dsn1p) which joins kinetochore subunits contacting DNA to those contacting microtubules; critical to kinetochore assembly ORF Verified inviable YAL038W S000000036 CDC19 Pyruvate kinase, functions as a homotetramer in glycolysis to convert phosphoenolpyruvate to pyruvate, the input for aerobic (TCA cycle) or anaerobic (glucose fermentation) respiration ORF Verified inviable YAL041W S000000039 CDC24 Guanine nucleotide exchange factor (GEF or GDP-release factor) for Cdc42p; required for polarity establishment and maintenance, and mutants have morphological defects in bud formation and shmooing ORF Verified inviable YAL043C S000000041 PTA1 Subunit of holo-CPF, a multiprotein complex and functional homolog of mammalian CPSF, required for the cleavage and polyadenylation of mRNA and snoRNA 3' ends; involved in pre-tRNA processing; binds to the phosphorylated CTD of RNAPII ORF Verified inviable YAR007C S000000065 RFA1 Subunit of heterotrimeric Replication Factor A (RF-A), which is a highly conserved single-stranded DNA binding protein involved in DNA replication, repair, and recombination ORF Verified inviable YAR008W S000000066 SEN34 Subunit of the tRNA splicing endonuclease, which is composed of Sen2p, Sen15p, Sen34p, and Sen54p; Sen34p contains the active site for tRNA 3' splice site cleavage and has similarity to Sen2p and to Archaeal tRNA splicing endonuclease ORF Verified inviable YAR019C S000000072 CDC15 Protein kinase of the Mitotic Exit Network that is localized to the spindle pole bodies at late anaphase; promotes mitotic exit by directly switching on the kinase activity of Dbf2p ORF Verified inviable YBL004W S000000100 UTP20 Component of the small-subunit (SSU) processome, which is involved in the biogenesis of the 18S rRNA ORF Verified inviable YBL014C S000000110 RRN6 Protein involved in the transcription of 35S rRNA genes by RNA polymerase I; component of the core factor (CF) complex also composed of Rrn11p, Rrn7p and TATA-binding protein ORF Verified inviable YBL018C S000000114 POP8 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends ORF Verified inviable YBL020W S000000116 RFT1 Flippase, essential integral membrane protein that is required for translocation of Man5GlcNac2-PP-Dol from the cytoplasmic side to the lumenal side of the ER membrane; mutation is suppressed by expression human p53 protein ORF Verified inviable YBL023C S000000119 MCM2 Protein involved in DNA replication; component of the Mcm2-7 hexameric complex that binds chromatin as a part of the pre-replicative complex ORF Verified inviable YBL026W S000000122 LSM2 Lsm (Like Sm) protein; part of heteroheptameric complexes (Lsm2p-7p and either Lsm1p or 8p): cytoplasmic Lsm1p complex involved in mRNA decay; nuclear Lsm8p complex part of U6 snRNP and possibly involved in processing tRNA, snoRNA, and rRNA ORF Verified inviable YBL030C S000000126 PET9 Major ADP/ATP carrier of the mitochondrial inner membrane, exchanges cytosolic ADP for mitochondrially synthesized ATP; required for viability in many common lab strains carrying a mutation in the polymorphic SAL1 gene ORF Verified inviable YBL034C S000000130 STU1 Component of the mitotic spindle that binds to interpolar microtubules via its association with beta-tubulin (Tub2p); required for interpolar microtubules to provide an outward force on the spindle poles ORF Verified inviable YBL035C S000000131 POL12 B subunit of DNA polymerase alpha-primase complex, required for initiation of DNA replication during mitotic and premeiotic DNA synthesis; also functions in telomere capping and length regulation ORF Verified inviable YBL040C S000000136 ERD2 Integral membrane protein that binds to the HDEL motif in proteins destined for retention in the endoplasmic reticulum; has a role in maintenance of normal levels of ER-resident proteins ORF Verified inviable YBL041W S000000137 PRE7 20S proteasome beta-type subunit ORF Verified inviable YBL050W S000000146 SEC17 Peripheral membrane protein required for vesicular transport between ER and Golgi and for the 'priming' step in homotypic vacuole fusion, part of the cis-SNARE complex; has similarity to alpha-SNAP ORF Verified inviable YBL073W S000000169 Hypothetical protein; open reading frame overlaps 5' end of essential AAR2 gene encoding a component of the U5 snRNP required for splicing of U3 precursors ORF Dubious inviable YBL074C S000000170 AAR2 Component of the U5 snRNP, required for splicing of U3 precursors; originally described as a splicing factor specifically required for splicing pre-mRNA of the MATa1 cistron ORF Verified inviable YBL076C S000000172 ILS1 Cytoplasmic isoleucine-tRNA synthetase, target of the G1-specific inhibitor reveromycin A ORF Verified inviable YBL077W S000000173 Hypothetical protein; open reading frame overlaps 3' end of essential ILS1 gene encoding cytoplasmic isoleucine-tRNA synthetase ORF Dubious inviable YBL084C S000000180 CDC27 Subunit of the Anaphase-Promoting Complex/Cyclosome (APC/C), which is a ubiquitin-protein ligase required for degradation of anaphase inhibitors, including mitotic cyclins, during the metaphase/anaphase transition ORF Verified inviable YBL092W S000000188 RPL32 Protein component of the large (60S) ribosomal subunit, has similarity to rat L32 ribosomal protein; overexpression disrupts telomeric silencing ORF Verified inviable YBL097W S000000193 BRN1 Essential protein required for chromosome condensation, likely to function as an intrinsic component of the condensation machinery, may influence multiple aspects of chromosome transmission and dynamics ORF Verified inviable YBL105C S000000201 PKC1 Protein serine/threonine kinase essential for cell wall remodeling during growth; localized to sites of polarized growth and the mother-daughter bud neck; homolog of the alpha, beta, and gamma isoforms of mammalian protein kinase C (PKC) ORF Verified inviable YBR002C S000000206 RER2 Cis-prenyltransferase involved in dolichol synthesis; participates in endoplasmic reticulum (ER) protein sorting ORF Verified inviable YBR004C S000000208 GPI18 Functional ortholog of human PIG-V, which is a mannosyltransferase that transfers the second mannose in glycosylphosphatidylinositol biosynthesis; the authentic, non-tagged protein was localized to mitochondria ORF Verified inviable YBR011C S000000215 IPP1 Cytoplasmic inorganic pyrophosphatase (PPase), catalyzes the rapid exchange of oxygens from Pi with water, highly expressed and essential for viability, active-site residues show identity to those from E. coli PPase ORF Verified inviable YBR029C S000000233 CDS1 Phosphatidate cytidylyltransferase (CDP-diglyceride synthetase); an enzyme that catalyzes that conversion of CTP + phosphate into diphosphate + CDP-diaclglyerol, a critical step in the synthesis of all major yeast phospholipids ORF Verified inviable YBR038W S000000242 CHS2 Chitin synthase II, requires activation from zymogenic form in order to catalyze the transfer of N-acetylglucosamine (GlcNAc) to chitin; required for the synthesis of chitin in the primary septum during cytokinesis ORF Verified inviable YBR049C S000000253 REB1 RNA polymerase I enhancer binding protein; DNA binding protein which binds to genes transcribed by both RNA polymerase I and RNA polymerase II; required for termination of RNA polymerase I transcription ORF Verified inviable YBR055C S000000259 PRP6 Splicing factor, component of the U4/U6-U5 snRNP complex ORF Verified inviable YBR060C S000000264 ORC2 Subunit of the origin recognition complex, which directs DNA replication by binding to replication origins and is also involved in transcriptional silencing; may be phosphorylated by Cdc28p ORF Verified inviable YBR070C S000000274 ALG14 Component of UDP-GlcNAc transferase required for the second step of dolichyl-linked oligosaccharide synthesis; anchors the catalytic subunit Alg13p to the ER membrane; similar to bacterial and human glycosyltransferases ORF Verified inviable YBR079C S000000283 RPG1 Subunit of the core complex of translation initiation factor 3(eIF3), essential for translation; part of a subcomplex (Prt1p-Rpg1p-Nip1p) that stimulates binding of mRNA and tRNA(i)Met to ribosomes ORF Verified inviable YBR080C S000000284 SEC18 ATPase required for the release of Sec17p during the 'priming' step in homotypic vacuole fusion and for ER to Golgi transport; homolog of the mammalian NSF ORF Verified inviable YBR087W S000000291 RFC5 Subunit of heteropentameric Replication factor C (RF-C), which is a DNA binding protein and ATPase that acts as a clamp loader of the proliferating cell nuclear antigen (PCNA) processivity factor for DNA polymerases delta and epsilon ORF Verified inviable YBR088C S000000292 POL30 Proliferating cell nuclear antigen (PCNA), functions as the sliding clamp for DNA polymerase delta; may function as a docking site for other proteins required for mitotic and meiotic chromosomal DNA replication and for DNA repair ORF Verified inviable YBR089W S000000293 Hypothetical protein ORF Dubious inviable YBR091C S000000295 MRS5 Essential protein of the inner mitochondrial membrane, peripherally localized; component of the TIM22 complex, which is a twin-pore translocase that mediates insertion of numerous multispanning inner membrane proteins ORF Verified inviable YBR102C S000000306 EXO84 Essential protein with dual roles in spliceosome assembly and exocytosis; the exocyst complex (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p, and Exo84p) mediates polarized targeting of secretory vesicles to active sites of exocytosis ORF Verified inviable YBR109C S000000313 CMD1 Calmodulin; Ca++ binding protein that regulates Ca++ independent processes (mitosis, bud growth, actin organization, endocytosis, etc.) and Ca++ dependent processes (stress-activated pathways), targets include Nuf1p, Myo2p and calcineurin ORF Verified inviable YBR110W S000000314 ALG1 Mannosyltransferase, involved in asparagine-linked glycosylation in the endoplasmic reticulum (ER); essential for viability, mutation is functionally complemented by human ortholog ORF Verified inviable YBR121C S000000325 GRS1 Cytoplasmic and mitochondrial glycyl-tRNA synthase that ligates glycine to the cognate anticodon bearing tRNA; transcription termination factor that may interact with the 3'-end of pre-mRNA to promote 3'-end formation ORF Verified inviable YBR123C S000000327 TFC1 One of six subunits of the RNA polymerase III transcription initiation factor complex (TFIIIC); part of the TauA globular domain of TFIIIC that binds DNA at the BoxA promoter sites of tRNA and similar genes; human homolog is TFIIIC-63 ORF Verified inviable YBR124W S000000328 Hypothetical protein ORF Dubious inviable YBR135W S000000339 CKS1 Subunit of the Cdc28 protein kinase, required for mitotic proteolysis, may also be involved in the proteolysis of the G1 cyclins ORF Verified inviable YBR136W S000000340 MEC1 Genome integrity checkpoint protein and PI kinase superfamily member; signal transducer required for cell cycle arrest and transcriptional responses prompted by damaged or unreplicated DNA; monitors and participates in meiotic recombination ORF Verified inviable YBR140C S000000344 IRA1 GTPase-activating protein that negatively regulates RAS by converting it from the GTP- to the GDP-bound inactive form, required for reducing cAMP levels under nutrient limiting conditions, mediates membrane association of adenylate cyclase ORF Verified inviable YBR142W S000000346 MAK5 Essential nucleolar protein, putative DEAD-box RNA helicase required for maintenance of M1 dsRNA virus; involved in biogenesis of large (60S) ribosomal subunits ORF Verified inviable YBR143C S000000347 SUP45 Polypeptide release factor involved in translation termination; mutant form acts as a recessive omnipotent suppressor ORF Verified inviable YBR152W S000000356 SPP381 mRNA splicing factor, component of U4/U6.U5 tri-snRNP; interacts genetically and physically with Prp38p ORF Verified inviable YBR153W S000000357 RIB7 Diaminohydroxyphoshoribosylaminopyrimidine deaminase; catalyzes the second step of the riboflavin biosynthesis pathway ORF Verified inviable YBR154C S000000358 RPB5 RNA polymerase subunit ABC27, common to RNA polymerases I, II, and III; contacts DNA and affects transactivation ORF Verified inviable YBR155W S000000359 CNS1 TPR-containing co-chaperone; binds both Hsp82p (Hsp90) and Ssa1p (Hsp70) and stimulates the ATPase activity of SSA1, ts mutants reduce Hsp82p function while over expression suppresses the phenotypes of an HSP82 ts allele and a cpr7 deletion ORF Verified inviable YBR160W S000000364 CDC28 Catalytic subunit of the main cell cycle cyclin-dependent kinase (CDK); alternately associates with G1 cyclins (CLNs) and G2/M cyclins (CLBs) which direct the CDK to specific substrates ORF Verified inviable YBR167C S000000371 POP7 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends ORF Verified inviable YBR190W S000000394 Hypothetical protein ORF Dubious inviable YBR192W S000000396 RIM2 Mitochondrial pyrimidine nucleotide transporter; imports pyrimidine nucleoside triphosphates and exports pyrimidine nucleoside monophosphates; member of the mitochondrial carrier family ORF Verified inviable YBR193C S000000397 MED8 Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; essential for transcriptional regulation ORF Verified inviable YBR196C S000000400 PGI1 Glycolytic enzyme phosphoglucose isomerase, catalyzes the interconversion of glucose-6-phosphate and fructose-6-phosphate; required for cell cycle progression and completion of the gluconeogenic events of sporulation ORF Verified inviable YBR198C S000000402 TAF5 Subunit (90 kDa) of TFIID and SAGA complexes, involved in RNA polymerase II transcription initiation and in chromatin modification ORF Verified inviable YBR202W S000000406 CDC47 Component of the hexameric MCM complex, which is important for priming origins of DNA replication in G1 and becomes an active ATP-dependent helicase that promotes DNA melting and elongation when activated by Cdc7p-Dbf4p in S-phase ORF Verified inviable YBR211C S000000415 AME1 Essential kinetochore protein associated with microtubules and spindle pole bodies; component of the kinetochore sub-complex COMA (Ctf19p, Okp1p, Mcm21p, Ame1p); involved in spindle checkpoint maintenance ORF Verified inviable YBR234C S000000438 ARC40 Essential subunit of the ARP2/3 complex, which is required for the motility and integrity of cortical actin patches ORF Verified inviable YBR236C S000000440 ABD1 Methyltransferase, catalyzes the transfer of a methyl group from S-adenosylmethionine to the GpppN terminus of capped mRNA ORF Verified inviable YBR237W S000000441 PRP5 RNA helicase in the DEAD-box family, necessary for prespliceosome formation, bridges U1 and U2 snRNPs and enables stable U2 snRNP association with intron RNA ORF Verified inviable YBR243C S000000447 ALG7 UDP-N-acetyl-glucosamine-1-P transferase, transfers Glc-Nac-P from UDP-GlcNac to Dol-P in the ER in the first step of the dolichol pathway of protein asparagine-linked glycosylation; inhibited by tunicamycin ORF Verified inviable YBR247C S000000451 ENP1 Protein associated with U3 and U14 snoRNAs, required for pre-rRNA processing and 40S ribosomal subunit synthesis; localized in the nucleus and concentrated in the nucleolus ORF Verified inviable YBR252W S000000456 DUT1 dUTPase, catalyzes the hydrolysis of dUTP to dUMP and PPi and thereby prevents the incorporation of uracil into DNA during replication ORF Verified inviable YBR253W S000000457 SRB6 Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; essential for transcriptional regulation ORF Verified inviable YBR254C S000000458 TRS20 One of 10 subunits of the transport protein particle (TRAPP) complex of the cis-Golgi which mediates vesicle docking and fusion; mutations in the human homolog cause the spondyloepiphyseal dysplasia tarda (SEDL) disorder ORF Verified inviable YBR256C S000000460 RIB5 Riboflavin synthase; catalyzes the last step of the riboflavin biosynthesis pathway ORF Verified inviable YBR257W S000000461 POP4 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends; binds to the RPR1 RNA subunit in Rnase P ORF Verified inviable YBR265W S000000469 TSC10 3-ketosphinganine reductase, catalyzes the second step in phytosphingosine synthesis, essential for growth in the absence of exogenous dihydrosphingosine or phytosphingosine, member of short chain dehydrogenase/reductase protein family ORF Verified inviable YCL004W S000000510 PGS1 Phosphatidylglycerolphosphate synthase, catalyzes the synthesis of phosphatidylglycerolphosphate from CDP-diacylglycerol and sn-glycerol 3-phosphate in the first committed and rate-limiting step of cardiolipin biosynthesis ORF Verified inviable YCL017C S000000522 NFS1 Cysteine desulfurase involved in iron-sulfur cluster (Fe/S) biogenesis; required for the post-transcriptional thio-modification of mitochondrial and cytoplasmic tRNAs; essential protein located predominantly in mitochondria ORF Verified inviable YCL031C S000000536 RRP7 Essential protein involved in rRNA processing and ribosome biogenesis ORF Verified inviable YCL041C S000000546 Hypothetical protein; open reading frame overlaps 5' end of essential PDI1 gene encoding protein disulfide isomerase ORF Dubious inviable YCL043C S000000548 PDI1 Protein disulfide isomerase, multifunctional protein resident in the endoplasmic reticulum lumen, essential for the formation of disulfide bonds in secretory and cell-surface proteins, unscrambles non-native disulfide bonds ORF Verified inviable YCL052C S000000557 PBN1 Essential component of glycosylphosphatidylinositol-mannosyltransferase I, required for the autocatalytic post-translational processing of the protease B precursor Prb1p, localizes to ER in lumenal orientation; homolog of mammalian PIG-X ORF Verified inviable YCL054W S000000559 SPB1 AdoMet-dependent methyltransferase involved in rRNA processing and 60S ribosomal subunit maturation; methylates G2922 in the tRNA docking site of the large subunit rRNA and in the absence of snR52, U2921; suppressor of PAB1 mutants ORF Verified inviable YCL059C S000000564 KRR1 Essential nucleolar protein required for the synthesis of 18S rRNA and for the assembly of 40S ribosomal subunit ORF Verified inviable YCR012W S000000605 PGK1 3-phosphoglycerate kinase, catalyzes transfer of high-energy phosphoryl groups from the acyl phosphate of 1,3-bisphosphoglycerate to ADP to produce ATP; key enzyme in glycolysis and gluconeogenesis ORF Verified inviable YCR013C S000000606 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; extensively overlaps essential PGK1 gene encoding 3-phosphoglycerate kinase ORF Dubious inviable YCR035C S000000631 RRP43 Protein involved in rRNA processing; component of the exosome 3->5 exonuclease complex with Rrp41p, Rrp42p, Rrp4p and Dis3p; required for efficient maturation of 5.8S, 18S and 25S rRNA ORF Verified inviable YCR052W S000000648 RSC6 One of 15 subunits of the 'Remodel the Structure of Chromatin' (RSC) complex; essential for mitotic growth; homolog of SWI/SNF subunit Swp73p ORF Verified inviable YCR054C S000000650 CTR86 Essential protein of unknown function ORF Verified inviable YCR057C S000000653 PWP2 Conserved 90S pre-ribosomal component essential for proper endonucleolytic cleavage of the 35 S rRNA precursor at A0, A1, and A2 sites; contains eight WD-repeats; PWP2 deletion leads to defects in cell cycle and bud morphogenesis ORF Verified inviable YCR072C S000000668 RSA4 WD-repeat protein involved in ribosome biogenesis; required for maturation and efficient intra-nuclear transport or pre-60S ribosomal subunits, localizes to the nucleolus ORF Verified inviable YCR093W S000000689 CDC39 Component of the CCR4-NOT complex, which has multiple roles in regulating mRNA levels including regulation of transcription and destabilizing mRNAs by deadenylation; basal transcription factor ORF Verified inviable YDL003W S000002161 MCD1 Essential protein required for sister chromatid cohesion in mitosis and meiosis; subunit of the cohesin complex; expression is cell cycle regulated and peaks in S phase ORF Verified inviable YDL004W S000002162 ATP16 Delta subunit of the central stalk of mitochondrial F1F0 ATP synthase, which is a large, evolutionarily conserved enzyme complex required for ATP synthesis ORF Verified inviable YDL007W S000002165 RPT2 One of six ATPases of the 19S regulatory particle of the 26S proteasome involved in the degradation of ubiquitinated substrates; required for normal peptide hydrolysis by the core 20S particle ORF Verified inviable YDL008W S000002166 APC11 Catalytic core subunit of the Anaphase-Promoting Complex/Cyclosome (APC/C), which is a ubiquitin-protein ligase required for degradation of anaphase inhibitors, including mitotic cyclins, during the metaphase/anaphase transition ORF Verified inviable YDL014W S000002172 NOP1 Nucleolar protein, component of the small subunit processome complex, which is required for processing of pre-18S rRNA; has similarity to mammalian fibrillarin ORF Verified inviable YDL015C S000002173 TSC13 Enoyl reductase that catalyzes the last step in each cycle of very long chain fatty acid elongation, localizes to the ER, highly enriched in a structure marking nuclear-vacuolar junctions, coimmunoprecipitates with elongases Fen1p and Sur4p ORF Verified inviable YDL016C S000002174 Hypothetical protein; open reading frame overlaps 3' end of essential CDC7 gene encoding the catalytic subunit of the Cdc7p-Dbf4p kinase complex ORF Dubious inviable YDL017W S000002175 CDC7 DDK (Dbf4-dependent kinase) catalytic subunit required for firing origins and replication fork progression in mitosis through phosphorylation of Mcm2-7p complexes and Cdc45p; kinase activity correlates with cyclical DBF4 expression ORF Verified inviable YDL028C S000002186 MPS1 Dual-specificity kinase required for spindle pole body (SPB) duplication and spindle checkpoint function; substrates include SPB proteins Spc42p, Spc110p, and Spc98p, mitotic exit network protein Mob1p, and checkpoint protein Mad1p ORF Verified inviable YDL029W S000002187 ARP2 Essential component of the Arp2/3 complex, which is a highly conserved actin nucleation center required for the motility and integrity of actin patches; involved in endocytosis and membrane growth and polarity ORF Verified inviable YDL030W S000002188 PRP9 Subunit of the SF3a splicing factor complex, required for spliceosome assembly; acts after the formation of the U1 snRNP-pre-mRNA complex ORF Verified inviable YDL031W S000002189 DBP10 Putative ATP-dependent RNA helicase of the DEAD-box protein family, constituent of 66S pre-ribosomal particles; essential protein involved in ribosome biogenesis ORF Verified inviable YDL043C S000002201 PRP11 Subunit of the SF3a splicing factor complex, required for spliceosome assembly ORF Verified inviable YDL045C S000002203 FAD1 Flavin adenine dinucleotide (FAD) synthetase, performs the second step in synthesis of FAD from riboflavin ORF Verified inviable YDL055C S000002213 PSA1 GDP-mannose pyrophosphorylase (mannose-1-phosphate guanyltransferase), synthesizes GDP-mannose from GTP and mannose-1-phosphate in cell wall biosynthesis; required for normal cell wall structure ORF Verified inviable YDL058W S000002216 USO1 Essential protein involved in intracellular protein transport, coiled-coil protein necessary for transport from ER to Golgi; required for assembly of the ER-to-Golgi SNARE complex ORF Verified inviable YDL060W S000002218 TSR1 Protein required for processing of 20S pre-rRNA in the cytoplasm, associates with pre-40S ribosomal particles ORF Verified inviable YDL064W S000002222 UBC9 SUMO-conjugating enzyme involved in the Smt3p conjugation pathway; nuclear protein required for S- and M-phase cyclin degradation and mitotic control; involved in proteolysis mediated by the anaphase-promoting complex cyclosome (APCC) ORF Verified inviable YDL084W S000002242 SUB2 Component of the TREX complex required for nuclear mRNA export; DEAD-box RNA helicase involved in early and late steps of spliceosome assembly; homolog of the human splicing factor hUAP56 ORF Verified inviable YDL087C S000002245 LUC7 Essential protein associated with the U1 snRNP complex; splicing factor involved in recognition of 5' splice site ORF Verified inviable YDL092W S000002250 SRP14 Signal recognition particle (SRP) subunit, interacts with the RNA component of SRP to form the Alu domain, which is the region of SRP responsible for arrest of nascent chain elongation during membrane targeting; homolog of mammalian SRP14 ORF Verified inviable YDL097C S000002255 RPN6 Essential, non-ATPase regulatory subunit of the 26S proteasome lid required for the assembly and activity of the 26S proteasome; the human homolog (S9 protein) partially rescues Rpn6p depletion ORF Verified inviable YDL098C S000002256 SNU23 Component of U4/U6.U5 snRNP involved in mRNA splicing via spliceosome ORF Verified inviable YDL102W S000002260 CDC2 Catalytic subunit of DNA polymerase delta; required for chromosomal DNA replication during mitosis and meiosis, intragenic recombination, repair of double strand DNA breaks, and DNA replication during nucleotide excision repair (NER) ORF Verified inviable YDL103C S000002261 QRI1 UDP-N-acetylglucosamine pyrophosphorylase, catalyzes the formation of UDP-N-acetylglucosamine (UDP-GlcNAc), which is important in cell wall biosynthesis, protein N-glycosylation, and GPI anchor biosynthesis ORF Verified inviable YDL105W S000002263 NSE4 Nuclear protein that plays a role in the function of the Smc5p-Rhc18p complex ORF Verified inviable YDL108W S000002266 KIN28 Serine/threonine protein kinase, subunit of the transcription factor TFIIH; involved in transcription initiation at RNA polymerase II promoters ORF Verified inviable YDL111C S000002269 RRP42 Protein involved in rRNA processing; component of the exosome 3->5 exonuclease complex with Rrp4p, Rrp41p, Rrp43p and Dis3p ORF Verified inviable YDL120W S000002278 YFH1 Frataxin, regulates mitochondrial iron accumulation; interacts with Isu1p which promotes Fe-S cluster assembly; interacts with electron transport chain components and may influence respiration; human homolog involved in Friedrich's ataxia ORF Verified inviable YDL126C S000002284 CDC48 ATPase in ER, nuclear membrane and cytosol with homology to mammalian p97; in a complex with Npl4p and Ufd1p participates in retrotranslocation of ubiquitinated proteins from the ER into the cytosol for degradation by the proteasome ORF Verified inviable YDL132W S000002290 CDC53 Cullin, structural protein of SCF complexes (which also contain Skp1p, Cdc34p, and an F-box protein) involved in ubiquitination; SCF promotes the G1-S transition by targeting G1 cyclins and the Cln-CDK inhibitor Sic1p for degradation ORF Verified inviable YDL139C S000002298 SCM3 Protein of unknown function; isolated as a high-copy suppressor of mutations in the histone fold domain (HFD) of CSE4 ORF Uncharacterized inviable YDL140C S000002299 RPO21 RNA polymerase II largest subunit B220, part of central core; phosphorylation of C-terminal heptapeptide repeat domain regulates association with transcription and splicing factors; similar to bacterial beta-prime ORF Verified inviable YDL141W S000002300 BPL1 Biotin:apoprotein ligase, covalently modifies proteins with the addition of biotin, required for acetyl-CoA carboxylase (Acc1p) holoenzyme formation ORF Verified inviable YDL143W S000002302 CCT4 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YDL145C S000002304 COP1 Alpha subunit of COPI vesicle coatomer complex, which surrounds transport vesicles in the early secretory pathway ORF Verified inviable YDL147W S000002306 RPN5 Essential, non-ATPase regulatory subunit of the 26S proteasome lid, similar to mammalian p55 subunit and to another S. cerevisiae regulatory subunit, Rpn7p ORF Verified inviable YDL148C S000002307 NOP14 Nucleolar protein, forms a complex with Noc4p that mediates maturation and nuclear export of 40S ribosomal subunits; also present in the small subunit processome complex, which is required for processing of pre-18S rRNA ORF Verified inviable YDL150W S000002309 RPC53 RNA polymerase III subunit C53 ORF Verified inviable YDL152W S000002311 Hypothetical protein; open reading frame overlaps 5' end of essential SAS10 gene encoding a component of the small ribosomal subunit processosome ORF Dubious inviable YDL153C S000002312 SAS10 Component of the small (ribosomal) subunit (SSU) processosome required for pre-18S rRNa processing; essential nucleolar protein that, when overproduced, disrupts silencing ORF Verified inviable YDL163W S000002322 Hypothetical protein; open reading frame overlaps 5' end of essential CDC9 gene encoding DNA ligase ORF Dubious inviable YDL164C S000002323 CDC9 DNA ligase found in the nucleus and mitochondria, an essential enzyme that joins Okazaki fragments during DNA replication; also acts in nucleotide excision repair, base excision repair, and recombination ORF Verified inviable YDL165W S000002324 CDC36 Component of the CCR4-NOT complex, which has multiple roles in regulating mRNA levels including regulation of transcription and destabilizing mRNAs by deadenylation; basal transcription factor ORF Verified inviable YDL166C S000002325 FAP7 Essential NTPase required for small ribosome subunit synthesis, mediates processing of the 20S pre-rRNA at site D in the cytoplasm but associates only transiently with 43S preribosomes via Rps14p, may be the endonuclease for site D ORF Verified inviable YDL193W S000002352 NUS1 Prenyltransferase, required for cell viability ORF Uncharacterized inviable YDL195W S000002354 SEC31 Essential phosphoprotein component (p150) of the COPII coat of secretory pathway vesicles, in complex with Sec13p; required for ER-derived transport vesicle formation ORF Verified inviable YDL196W S000002355 Hypothetical protein; open reading frame is located in promoter region of essential SEC31 gene encoding a component of the COPII secretory vesicle coat ORF Dubious inviable YDL205C S000002364 HEM3 Phorphobilinogen deaminase, catalyzes the conversion of 4-porphobilinogen to hydroxymethylbilane, the third step in the heme biosynthetic pathway; localizes to both the cytoplasm and nucleus; expression is regulated by Hap2p-Hap3p ORF Verified inviable YDL207W S000002366 GLE1 Cytoplasmic nucleoporin required for polyadenylated RNA export but not for protein import; component of Nup82p nuclear pore subcomplex; contains a nuclear export signal ORF Verified inviable YDL208W S000002367 NHP2 Nuclear protein related to mammalian high mobility group (HMG) proteins, essential for function of H/ACA-type snoRNPs, which are involved in 18S rRNA processing ORF Verified inviable YDL209C S000002368 CWC2 Protein involved in pre-mRNA splicing, component of a complex containing Cef1p; interacts with Prp19p; contains an RNA recognition motif; has similarity to S. pombe Cwf2p ORF Verified inviable YDL212W S000002371 SHR3 Endoplasmic reticulum packaging chaperone, required for incorporation of amino acid permeases into COPII coated vesicles for transport to the cell surface ORF Verified inviable YDL217C S000002376 TIM22 Component of the mitochondrial Tim54p-Tim22p complex involved in insertion of polytopic proteins into the inner membrane ORF Verified inviable YDL220C S000002379 CDC13 Single stranded DNA-binding protein found at TG1-3 telomere G-tails; regulates telomere replication through recruitment of specific sub-complexes, but the essential function is telomere capping ORF Verified inviable YDL221W S000002380 Hypothetical protein; open reading frame overlaps 3' end of essential CDC13 gene encoding a telomere capping protein ORF Dubious inviable YDL235C S000002394 YPD1 Phosphorelay intermediate protein, phosphorylated by the plasma membrane sensor Sln1p in response to osmotic stress and then in turn phosphorylates the response regulators Ssk1p in the cytosol and Skn7p in the nucleus ORF Verified inviable YDR002W S000002409 YRB1 Ran GTpase binding protein; involved in nuclear protein import and RNA export, ubiquitin-mediated protein degradation during the cell cycle; shuttles between the nucleus and cytoplasm; is essential; homolog of human RanBP1 ORF Verified inviable YDR013W S000002420 PSF1 Subunit of the GINS complex (Sld5p, Psf1p, Psf2p, Psf3p), which is localized to DNA replication origins and implicated in assembly of the DNA replication machinery ORF Verified inviable YDR016C S000002423 DAD1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segregation; is transferred to the kinetochore prior to mitosis ORF Verified inviable YDR021W S000002428 FAL1 Nucleolar protein required for maturation of 18S rRNA, member of the eIF4A subfamily of DEAD-box ATP-dependent RNA helicases ORF Verified inviable YDR023W S000002430 SES1 Cytosolic seryl-tRNA synthetase, class II aminoacyl-tRNA synthetase that aminoacylates tRNA(Ser), displays tRNA-dependent amino acid recognition which enhances discrimination of the serine substrate, interacts with peroxin Pex21p ORF Verified inviable YDR037W S000002444 KRS1 Lysyl-tRNA synthetase; also identified as a negative regulator of general control of amino acid biosynthesis ORF Verified inviable YDR041W S000002448 RSM10 Mitochondrial ribosomal protein of the small subunit, has similarity to E. coli S10 ribosomal protein; essential for viability, unlike most other mitoribosomal proteins ORF Verified inviable YDR044W S000002451 HEM13 Coproporphyrinogen III oxidase, an oxygen requiring enzyme that catalyzes the sixth step in the heme biosynthetic pathway; localizes to the mitochondrial inner membrane; transcription is repressed by oxygen and heme (via Rox1p and Hap1p) ORF Verified inviable YDR045C S000002452 RPC11 RNA polymerase III subunit C11; mediates pol III RNA cleavage activity and is important for termination of transcription ORF Verified inviable YDR047W S000002454 HEM12 Uroporphyrinogen decarboxylase, catalyzes the fifth step in the heme biosynthetic pathway; localizes to both the cytoplasm and nucleus; activity inhibited by Cu2+, Zn2+, Fe2+, Fe3+ and sulfhydryl-specific reagents ORF Verified inviable YDR050C S000002457 TPI1 Triose phosphate isomerase, abundant glycolytic enzyme; mRNA half-life is regulated by iron availability; transcription is controlled by activators Reb1p, Gcr1p, and Rap1p through binding sites in the 5' non-coding region ORF Verified inviable YDR052C S000002459 DBF4 Regulatory subunit of Cdc7p-Dbf4p kinase complex, required for Cdc7p kinase activity and initiation of DNA replication; phosphorylates the Mcm2-7 family of proteins; cell cycle regulated ORF Verified inviable YDR053W S000002460 Hypothetical protein; open reading frame overlaps 5' end of essential DBF4 gene encoding the regulatory subunit of the Cdc7p-Dbf4p kinase complex ORF Dubious inviable YDR054C S000002461 CDC34 Ubiquitin-conjugating enzyme or E2; together with Skp1p, Rbx1p, Cdc53p, and an F-box protein, forms a ubiquitin-protein ligase called the SCF complex which regulates cell cycle progression by targeting key substrates for degradation ORF Verified inviable YDR060W S000002467 MAK21 Constituent of 66S pre-ribosomal particles, required for large (60S) ribosomal subunit biogenesis; involved in nuclear export of pre-ribosomes; required for maintenance of dsRNA virus; homolog of human CAATT-binding protein ORF Verified inviable YDR062W S000002469 LCB2 Component of serine palmitoyltransferase, responsible along with Lcb1p for the first committed step in sphingolipid synthesis, which is the condensation of serine with palmitoyl-CoA to form 3-ketosphinganine ORF Verified inviable YDR064W S000002471 RPS13 Protein component of the small (40S) ribosomal subunit; has similarity to E. coli S15 and rat S13 ribosomal proteins ORF Verified inviable YDR081C S000002488 PDC2 Transcription factor required for the synthesis of the glycolytic enzyme pyruvate decarboxylase, required for high level expression of both the THI and the PDC genes ORF Verified inviable YDR082W S000002489 STN1 Telomere end-binding and capping protein, plays a key role with Pol12p in linking telomerase action with completion of lagging strand synthesis, and in a regulatory step required for telomere capping ORF Verified inviable YDR086C S000002493 SSS1 Subunit of the Sec61p translocation complex (Sec61p-Sss1p-Sbh1p) that forms a channel for passage of secretory proteins through the endoplasmic reticulum membrane, and of the Ssh1p complex (Ssh1p-Sbh2p-Sss1p); interacts with Ost4p and Wbp1p ORF Verified inviable YDR087C S000002494 RRP1 Essential evolutionarily conserved nucleolar protein necessary for biogenesis of 60S ribosomal subunits and processing of pre-rRNAs to mature rRNAs, associated with several distinct 66S pre-ribosomal particles ORF Verified inviable YDR088C S000002495 SLU7 RNA splicing factor, required for ATP-independent portion of 2nd catalytic step of spliceosomal RNA splicing; interacts with Prp18p; contains zinc knuckle domain ORF Verified inviable YDR091C S000002498 RLI1 Essential iron-sulfur protein required for ribosome biogenesis and translation initiation; facilitates binding of a multifactor complex (MFC) of translation initiation factors to the small ribosomal subunit; predicted ABC family ATPase ORF Verified inviable YDR113C S000002520 PDS1 Securin that inhibits anaphase by binding separin Esp1p, also blocks cyclin destruction and mitotic exit, essential for cell cycle arrest in mitosis in the presence of DNA damage or aberrant mitotic spindles; also present in meiotic nuclei ORF Verified inviable YDR118W S000002525 APC4 Subunit of the Anaphase-Promoting Complex/Cyclosome (APC/C), which is a ubiquitin-protein ligase required for degradation of anaphase inhibitors, including mitotic cyclins, during the metaphase/anaphase transition ORF Verified inviable YDR141C S000002548 DOP1 Protein of unknown function, essential for viability, involved in establishing cellular polarity and morphogenesis; green fluorescent protein (GFP)-fusion protein localizes to the cytoplasm in a punctate pattern ORF Verified inviable YDR145W S000002552 TAF12 Subunit (61/68 kDa) of TFIID and SAGA complexes, involved in RNA polymerase II transcription initiation and in chromatin modification, similar to histone H2A ORF Verified inviable YDR160W S000002567 SSY1 Component of the SPS plasma membrane amino acid sensor system (Ssy1p-Ptr3p-Ssy5p), which senses external amino acid concentration and transmits intracellular signals that result in regulation of expression of amino acid permease genes ORF Verified inviable YDR164C S000002571 SEC1 Sm-like protein involved in docking and fusion of exocytic vesicles through binding to assembled SNARE complexes at the membrane; localization to sites of secretion (bud neck and bud tip) is dependent on SNARE function ORF Verified inviable YDR166C S000002573 SEC5 Essential 107kDa subunit of the exocyst complex (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p, and Exo84p), which has the essential function of mediating polarized targeting of secretory vesicles to active sites of exocytosis ORF Verified inviable YDR167W S000002574 TAF10 Subunit (145 kDa) of TFIID and SAGA complexes, involved in RNA polymerase II transcription initiation and in chromatin modification ORF Verified inviable YDR168W S000002575 CDC37 Essential Hsp90p co-chaperone; necessary for passage through the START phase of the cell cycle ORF Verified inviable YDR170C S000002577 SEC7 Guanine nucleotide exchange factor (GEF) for ADP ribosylation factors involved in proliferation of the Golgi, intra-Golgi transport and ER-to-Golgi transport; found in the cytoplasm and on Golgi-associated coated vesicles ORF Verified inviable YDR172W S000002579 SUP35 Translation termination factor eRF3; altered protein conformation creates the [PSI(+)] prion, a dominant cytoplasmically inherited protein aggregate that alters translational fidelity and creates a nonsense suppressor phenotype ORF Verified inviable YDR177W S000002584 UBC1 Ubiquitin-conjugating enzyme that mediates selective degradation of short-lived and abnormal proteins; plays a role in vesicle biogenesis and ER-associated protein degradation (ERAD); component of the cellular stress response ORF Verified inviable YDR180W S000002588 SCC2 Subunit of cohesin loading factor (Scc2p-Scc4p), a complex required for the loading of cohesin complexes onto chromosomes; involved in establishing sister chromatid cohesion during DSB repair via histone H2AX ORF Verified inviable YDR182W S000002590 CDC1 Putative membrane protein of unknown function involved in Mn2+ homeostasis; mutants display actin and general growth defects, heterogeneous cell cycle arrests, and pleiotropic defects in cell cycle progression and organelle distribution ORF Verified inviable YDR187C S000002595 Hypothetical protein; open reading frame overlaps 5' end of essential CCT6 gene encoding a subunit of the cytosolic chaperonin Cct ring complex ORF Dubious inviable YDR188W S000002596 CCT6 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, essential protein that is required for the assembly of actin and tubulins in vivo; contains an ATP-binding motif ORF Verified inviable YDR189W S000002597 SLY1 Hydrophilic protein involved in vesicle trafficking between the ER and Golgi; SM (Sec1/Munc-18) family protein that binds the tSNARE Sed5p and stimulates its assembly into a trans-SNARE membrane-protein complex ORF Verified inviable YDR190C S000002598 RVB1 Essential protein involved in transcription regulation; component of chromatin remodeling complexes; required for assembly and function of the INO80 complex; member of the RUVB-like protein family ORF Verified inviable YDR196C S000002604 predicted to catalyze the final step in synthesis of Coenzyme A ORF Uncharacterized inviable YDR201W S000002609 SPC19 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segregation; also localized to nuclear side of spindle pole body ORF Verified inviable YDR208W S000002616 MSS4 Phosphatidylinositol-4-phosphate 5-kinase, involved in actin cytoskeleton organization and cell morphogenesis; multicopy suppressor of stt4 mutation ORF Verified inviable YDR211W S000002619 GCD6 Catalytic epsilon subunit of the translation initiation factor eIF2B, the guanine-nucleotide exchange factor for eIF2; activity subsequently regulated by phosphorylated eIF2; first identified as a negative regulator of GCN4 expression ORF Verified inviable YDR212W S000002620 TCP1 Alpha subunit of chaperonin-containing T-complex, which mediates protein folding in the cytosol; involved in maintenance of actin cytoskeleton; homolog to Drosophila melanogaster and mouse tailless complex polypeptide ORF Verified inviable YDR224C S000002632 HTB1 One of two nearly identical (see HTB2) histone H2B subtypes required for chromatin assembly and chromosome function; Rad6p-Bre1p-Lge1p mediated ubiquitination regulates transcriptional activation, meiotic DSB formation and H3 methylation ORF Verified inviable YDR228C S000002636 PCF11 mRNA 3' end processing factor, essential component of cleavage and polyadenylation factor IA (CF IA), involved in pre-mRNA 3' end processing and in transcription termination; binds C-terminal domain of largest subunit of RNA pol II (Rpo21p) ORF Verified inviable YDR232W S000002640 HEM1 5-aminolevulinate synthase, catalyzes the first step in the heme biosynthetic pathway; an N-terminal signal sequence is required for localization to the mitochondrial matrix; expression is regulated by Hap2p-Hap3p ORF Verified inviable YDR235W S000002643 PRP42 U1 snRNP protein involved in splicing, required for U1 snRNP biogenesis; contains multiple tetriatricopeptide repeats ORF Verified inviable YDR236C S000002644 FMN1 Riboflavin kinase, phosphorylates riboflavin to form riboflavin monophosphate (FMN), which is a necessary cofactor for many enzymes; localizes to microsomes and to the mitochondrial inner membrane ORF Verified inviable YDR238C S000002646 SEC26 Essential beta-coat protein of the COPI coatomer, involved in ER-to-Golgi protein trafficking and maintenance of normal ER morphology; shares 43% sequence identity with mammalian beta-coat protein (beta-COP) ORF Verified inviable YDR240C S000002648 SNU56 Component of U1 snRNP required for mRNA splicing via spliceosome; yeast specific, no metazoan counterpart; interacts with mRNA in commitment complex ORF Verified inviable YDR243C S000002651 PRP28 RNA helicase in the DEAD-box family, involved in RNA isomerization at the 5' splice site ORF Verified inviable YDR246W S000002654 TRS23 One of 10 subunits of the transport protein particle (TRAPP) complex of the cis-Golgi which mediates vesicle docking and fusion; involved in endoplasmic reticulum (ER) to Golgi membrane traffic; human homolog is TRAPPC4 ORF Verified inviable YDR267C S000002675 CIA1 Essential protein involved in assembly of cytosolic and nuclear iron-sulfur proteins ORF Verified inviable YDR280W S000002688 RRP45 Protein involved in rRNA processing; component of the exosome 3->5 exonuclease complex ORF Verified inviable YDR288W S000002696 NSE3 Essential subunit of the Mms21-Smc5-Smc6 complex; protein of unknown function; required for DNA repair and growth ORF Uncharacterized inviable YDR292C S000002700 SRP101 Signal recognition particle (SRP) receptor - alpha subunit; contain GTPase domains; involved in SRP-dependent protein targeting; interacts with SRP102p ORF Verified inviable YDR299W S000002707 BFR2 Essential protein possibly involved in secretion; multicopy suppressor of sensitivity to Brefeldin A ORF Verified inviable YDR301W S000002709 CFT1 RNA-binding subunit of the mRNA cleavage and polyadenylation factor; involved in poly(A) site recognition and required for both pre-mRNA cleavage and polyadenylation, 51% sequence similarity with mammalian AAUAA-binding subunit of CPSF ORF Verified inviable YDR302W S000002710 GPI11 ER membrane protein involved in a late step of glycosylphosphatidylinositol (GPI) anchor assembly; involved in the addition of phosphoethanolamine to the multiply mannosylated GPI intermediate; human PIG-Fp is a functional homolog ORF Verified inviable YDR303C S000002711 RSC3 One of 15 subunits of the 'Remodel the Structure of Chromatin' (RSC) complex; essential gene required for regulation of ribosomal protein genes and the cell wall/stress response; highly similar to Rsc30p ORF Verified inviable YDR308C S000002716 SRB7 Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; essential for transcriptional regulation; target of the global repressor Tup1p ORF Verified inviable YDR311W S000002719 TFB1 Subunit of TFIIH and nucleotide excision repair factor 3 complexes, required for nucleotide excision repair, target for transcriptional activators ORF Verified inviable YDR324C S000002732 UTP4 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YDR325W S000002733 YCG1 Non-SMC subunit of the condensin complex (Smc2p-Smc4p-Ycs4p-Brn1p-Ycg1p); required for establishment and maintenance of chromosome condensation, chromosome segregation and for chromatin binding of the condensin complex ORF Verified inviable YDR327W S000002735 Hypothetical protein; open reading frame overlaps 3' end of essential SKP1 gene encoding a conserved kinetochore protein ORF Dubious inviable YDR328C S000002736 SKP1 Evolutionarily conserved kinetochore protein that is part of multiple protein complexes, including the SCF ubiquitin ligase complex, the CBF3 complex that binds centromeric DNA, and the RAVE complex that regulates assembly of the V-ATPase ORF Verified inviable YDR331W S000002739 GPI8 ER membrane glycoprotein subunit of the glycosylphosphatidylinositol transamidase complex that adds glycosylphosphatidylinositol (GPI) anchors to newly synthesized proteins; human PIG-K protein is a functional homolog ORF Verified inviable YDR339C S000002747 FCF1 Essential nucleolar protein that is a component of the SSU (small subunit) processome involved in the pre-rRNA processing steps of 40S ribosomal subunit biogenesis; contains a PINc domain; copurifies with Faf1p ORF Verified inviable YDR341C S000002749 Cytoplasmic arginyl-tRNA synthetase ORF Verified inviable YDR353W S000002761 TRR1 Cytoplasmic thioredoxin reductase, key regulatory enzyme that determines the redox state of the thioredoxin system, which acts as a disulfide reductase system and protects cells against both oxidative and reductive stress ORF Verified inviable YDR355C S000002763 Hypothetical protein; open reading frame overlaps 5' end of essential SPC110 gene encoding an inner plaque spindle pole body component ORF Dubious inviable YDR356W S000002764 SPC110 Inner plaque spindle pole body (SPB) component, ortholog of human kendrin; involved in connecting nuclear microtubules to SPB; interacts with Tub4p-complex and calmodulin; phosphorylated by Mps1p in cell cycle-dependent manner ORF Verified inviable YDR361C S000002769 BCP1 Essential protein involved in nuclear export of Mss4p, which is a lipid kinase that generates phosphatidylinositol 4,5-biphosphate and plays a role in actin cytoskeleton organization and vesicular transport ORF Uncharacterized inviable YDR362C S000002770 TFC6 One of six subunits of RNA polymerase III transcription initiation factor complex (TFIIIC); part of TFIIIC TauB domain that binds BoxB promoter sites of tRNA and other genes; cooperates with Tfc3p in DNA binding; human homolog is TFIIIC-110 ORF Verified inviable YDR365C S000002773 ESF1 Nucleolar protein involved in pre-rRNA processing; depletion causes severely decreased 18S rRNA levels ORF Verified inviable YDR367W S000002775 Protein of unknown function; green fluorescent protein (GFP)-fusion protein localizes to the cytoplasm in a punctate pattern ORF Uncharacterized inviable YDR373W S000002781 FRQ1 N-myristoylated calcium-binding protein that may have a role in intracellular signaling through its regulation of the phosphatidylinositol 4-kinase Pik1p; member of the recoverin/frequenin branch of the EF-hand superfamily ORF Verified inviable YDR376W S000002784 ARH1 Oxidoreductase of the mitochondrial inner membrane, involved in cytoplasmic and mitochondrial iron homeostasis and required for activity of Fe-S cluster-containing enzymes; one of the few mitochondrial proteins essential for viability ORF Verified inviable YDR381W S000002789 YRA1 Nuclear protein that binds to RNA and to Mex67p, required for export of poly(A)+ mRNA from the nucleus; member of the REF (RNA and export factor binding proteins) family; another family member, Yra2p, can substitute for Yra1p function ORF Verified inviable YDR390C S000002798 UBA2 Nuclear protein that acts as a heterodimer with Aos1p to activate Smt3p (SUMO) before its conjugation to proteins (sumoylation), which may play a role in protein targeting; essential for viability ORF Verified inviable YDR394W S000002802 RPT3 One of six ATPases of the 19S regulatory particle of the 26S proteasome involved in the degradation of ubiquitinated substrates; substrate of N-acetyltransferase B ORF Verified inviable YDR396W S000002804 Hypothetical protein; open reading frame extensively overlaps essential NCB2 gene encoding the beta subunit of the NC2 dimeric histone-fold complex ORF Dubious inviable YDR397C S000002805 NCB2 Beta subunit of the NC2 dimeric histone-fold complex; represses RNA polymerase II transcription through binding to TBP and inhibition of TFIIA and TFIIB; homologous to the Dr1 subunit of the mammalian NC2 (negative cofactor2) ORF Verified inviable YDR398W S000002806 UTP5 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YDR404C S000002812 RPB7 RNA polymerase II subunit B16; forms two subunit dissociable complex with Rpb4p ORF Verified inviable YDR407C S000002815 TRS120 One of 10 subunits of the transport protein particle (TRAPP) complex of the cis-Golgi which mediates vesicle docking and fusion; involved in endoplasmic reticulum (ER) to Golgi membrane traffic ORF Verified inviable YDR412W S000002820 RRP17 Protein required for cell viability ORF Uncharacterized inviable YDR413C S000002821 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; overlaps the essential uncharacterized ORF YDR412W that is implicated in rRNA processing ORF Dubious inviable YDR416W S000002824 SYF1 Component of the spliceosome complex involved in pre-mRNA splicing; involved in regulation of cell cycle progression; similar to Drosophila crooked neck protein ORF Verified inviable YDR427W S000002835 RPN9 Non-ATPase regulatory subunit of the 26S proteasome, has similarity to putative proteasomal subunits in other species; null mutant is temperature sensitive and exhibits cell cycle and proteasome assembly defects ORF Verified inviable YDR429C S000002837 TIF35 Subunit of the core complex of translation initiation factor 3(eIF3), which is essential for translation ORF Verified inviable YDR434W S000002842 GPI17 Transmembrane protein subunit of the glycosylphosphatidylinositol transamidase complex that adds GPIs to newly synthesized proteins; human PIG-Sp homolog ORF Verified inviable YDR437W S000002845 GPI19 Subunit of GPI-GlcNAc transferase involved in synthesis of N-acetylglucosaminyl phosphatidylinositol (GlcNAc-PI), which is the first intermediate in glycosylphosphatidylinositol (GPI) anchor synthesis, shares similarity with mammalian PIG-P ORF Verified inviable YDR449C S000002857 UTP6 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YDR454C S000002862 GUK1 Guanylate kinase, converts GMP to GDP; required for growth and mannose outer chain elongation of cell wall N-linked glycoproteins ORF Verified inviable YDR460W S000002868 TFB3 Subunit of TFIIH and nucleotide excision repair factor 3 complexes, involved in transcription initiation, required for nucleotide excision repair; ring finger protein similar to mammalian CAK and TFIIH subunit ORF Verified inviable YDR464W S000002872 SPP41 Protein involved in negative regulation of expression of spliceosome components PRP4 and PRP3 ORF Verified inviable YDR468C S000002876 TLG1 Essential t-SNARE that forms a complex with Tlg2p and Vti1p and mediates fusion of endosome-derived vesicles with the late Golgi; binds the docking complex VFT (Vps fifty-three) through interaction with Vps51p ORF Verified inviable YDR472W S000002880 TRS31 One of 10 subunits of the transport protein particle (TRAPP) complex of the cis-Golgi which mediates vesicle docking and fusion; involved in endoplasmic reticulum (ER) to Golgi membrane traffic ORF Verified inviable YDR473C S000002881 PRP3 Splicing factor, component of the U4/U6-U5 snRNP complex ORF Verified inviable YDR478W S000002886 SNM1 Subunit of RNase MRP, which cleaves pre-rRNA; not shared between Rnase MRP and nuclear Rnase P, in contrast to all other Rnase MRP protein subunits; binds to the NME1 RNA subunit of Rnase MRP ORF Verified inviable YDR487C S000002895 RIB3 3,4-dihydroxy-2-butanone-4-phosphate synthase (DHBP synthase), required for riboflavin biosynthesis from ribulose-5-phosphate, also has an unrelated function in mitochondrial respiration ORF Verified inviable YDR489W S000002897 SLD5 Subunit of the GINS complex (Sld5p, Psf1p, Psf2p, Psf3p), which is localized to DNA replication origins and implicated in assembly of the DNA replication machinery ORF Verified inviable YDR498C S000002906 SEC20 Membrane glycoprotein v-SNARE involved in retrograde transport from the Golgi to the ER; required for N- and O-glycosylation in the Golgi but not in the ER; forms a complex with the cytosolic Tip20p ORF Verified inviable YDR499W S000002907 LCD1 Essential protein required for the DNA integrity checkpoint pathways; interacts physically with Mec1p; putative homolog of S. pombe Rad26 and human ATRIP ORF Verified inviable YDR510W S000002918 SMT3 Ubiquitin-like protein of the SUMO family, conjugated to lysine residues of target proteins; regulates chromatid cohesion, chromosome segregation, APC-mediated proteolysis, DNA replication and septin ring dynamics ORF Verified inviable YDR526C S000002934 Hypothetical protein ORF Dubious inviable YDR527W S000002935 RBA50 Protein involved in transcription; interacts with RNA polymerase II subunits Rpb2p, Rpb3, and Rpb11p; has similarity to human RPAP1 ORF Verified inviable YDR531W S000002939 Pantothenate kinase (ATP:D-pantothenate 4'-phosphotransferase, EC 2.7.1.33); catalyzes the first committed step in the universal biosynthetic pathway leading to coenzyme A1 ORF Uncharacterized inviable YEL002C S000000728 WBP1 Beta subunit of the oligosaccharyl transferase (OST) glycoprotein complex; required for N-linked glycosylation of proteins in the endoplasmic reticulum ORF Verified inviable YEL019C S000000745 MMS21 SUMO ligase involved in chromosomal organization and DNA repair; essential subunit of the Mms21-Smc5-Smc6 complex; mutants are sensitive to methyl methanesulfonate and show increased spontaneous mutation and mitotic recombination ORF Verified inviable YEL026W S000000752 SNU13 RNA binding protein, part of U3 snoRNP involved in rRNA processing, part of U4/U6-U5 tri-snRNP involved in mRNA splicing, similar to human 15.5K protein ORF Verified inviable YEL032W S000000758 MCM3 Protein involved in DNA replication; component of the Mcm2-7 hexameric complex that binds chromatin as a part of the pre-replicative complex ORF Verified inviable YEL034W S000000760 HYP2 Translation initiation factor eIF-5A, promotes formation of the first peptide bond; similar to and functionally redundant with Anb1p; undergoes an essential hypusination modification; expressed under aerobic conditions ORF Verified inviable YEL035C S000000761 UTR5 Protein of unknown function; transcription may be regulated by Gcr1p ORF Uncharacterized inviable YEL055C S000000781 POL5 Protein with sequence similarity to the human MybBP1A and weak sequence similar to B-type DNA polymerases, not required for chromosomal DNA replication; required for the synthesis of rRNA ORF Verified inviable YEL058W S000000784 PCM1 Essential N-acetylglucosamine-phosphate mutase, a hexosephosphate mutase involved in the biosynthesis of chitin ORF Verified inviable YER003C S000000805 PMI40 Mannose-6-phosphate isomerase, catalyzes the interconversion of fructose-6-P and mannose-6-P; required for early steps in protein mannosylation ORF Verified inviable YER006W S000000808 NUG1 GTPase that associates with nuclear 60S pre-ribosomes, required for export of 60S ribosomal subunits from the nucleus ORF Verified inviable YER008C S000000810 SEC3 Non-essential subunit of the exocyst complex (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p, Exo84p) which mediates targeting of post-Golgi vesicles to sites of active exocytosis; Sec3p specifically is a spatial landmark for secretion ORF Verified inviable YER009W S000000811 NTF2 Nuclear envelope protein, interacts with GDP-bound Gsp1p and with proteins of the nuclear pore to transport Gsp1p into the nucleus where it is an essential player in nucleocytoplasmic transport ORF Verified inviable YER012W S000000814 PRE1 20S proteasome beta-type subunit; localizes to the nucleus throughout the cell cycle ORF Verified inviable YER013W S000000815 PRP22 DEAH-box RNA-dependent ATPase/ATP-dependent RNA helicase, associates with lariat intermediates before the second catalytic step of splicing; mediates ATP-dependent mRNA release from the spliceosome and unwinds RNA duplexes ORF Verified inviable YER018C S000000820 SPC25 Component of the evolutionarily conserved kinetochore-associated Ndc80 complex (Ndc80p-Nuf2p-Spc24p-Spc25p); involved in chromosome segregation, spindle checkpoint activity and kinetochore clustering ORF Verified inviable YER021W S000000823 RPN3 Essential, non-ATPase regulatory subunit of the 26S proteasome lid, similar to the p58 subunit of the human 26S proteasome; temperature-sensitive alleles cause metaphase arrest, suggesting a role for the proteasome in cell cycle control ORF Verified inviable YER022W S000000824 SRB4 Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; essential for transcriptional regulation ORF Verified inviable YER023W S000000825 PRO3 Delta 1-pyrroline-5-carboxylate reductase, catalyzes the last step in proline biosynthesis ORF Verified inviable YER025W S000000827 GCD11 Gamma subunit of the translation initiation factor eIF2, involved in the identification of the start codon; binds GTP when forming the ternary complex with GTP and tRNAi-Met ORF Verified inviable YER036C S000000838 ARB1 ATPase of the ATP-binding cassette (ABC) family involved in 40S and 60S ribosome biogenesis, has similarity to Gcn20p; shuttles from nucleus to cytoplasm, physically interacts with Tif6p, Lsg1p ORF Uncharacterized inviable YER038C S000000840 KRE29 Essential subunit of the Mms21-Smc5-Smc6 complex; protein of unknown function; required for growth and DNA repair; heterozygous mutant shows haploinsufficiency in K1 killer toxin resistance ORF Verified inviable YER043C S000000845 SAH1 S-adenosyl-L-homocysteine hydrolase, catabolizes S-adenosyl-L-homocysteine which is formed after donation of the activated methyl group of S-adenosyl-L-methionine (AdoMet) to an acceptor ORF Verified inviable YER048W-A S000007237 ISD11 Protein required for mitochondrial iron-sulfur cluster biosynthesis ORF Uncharacterized inviable YER082C S000000884 UTP7 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YER093C S000000895 TSC11 Subunit of TORC2 (Tor2p-Lst8p-Avo1-Avo2-Tsc11p-Bit61p), a membrane-associated complex that regulates actin cytoskeletal dynamics during polarized growth and cell wall integrity; involved in sphingolipid metabolism; contains a RasGEFN domain ORF Verified inviable YER094C S000000896 PUP3 Beta subunit of the 20S proteasome involved in ubiquitin-dependent catabolism; human homolog is subunit C10 ORF Verified inviable YER104W S000000906 RTT105 Protein with a role in regulation of Ty1 transposition ORF Verified inviable YER112W S000000914 LSM4 Lsm (Like Sm) protein; part of heteroheptameric complexes (Lsm2p-7p and either Lsm1p or 8p): cytoplasmic Lsm1p complex involved in mRNA decay; nuclear Lsm8p complex part of U6 snRNP and possibly involved in processing tRNA, snoRNA, and rRNA ORF Verified inviable YER125W S000000927 RSP5 Ubiquitin-protein ligase involved in ubiquitin-mediated protein degradation; plays a role in heat shock element (HSE)-mediated gene expression and multivesicular body sorting; contains a hect (homologous to E6-AP carboxyl terminus) domain ORF Verified inviable YER126C S000000928 NSA2 Constituent of 66S pre-ribosomal particles, involved in 60S ribosomal subunit biogenesis ORF Verified inviable YER127W S000000929 LCP5 Essential protein involved in maturation of 18S rRNA; depletion leads to inhibited pre-rRNA processing and reduced polysome levels; localizes primarily to the nucleolus ORF Verified inviable YER133W S000000935 GLC7 Catalytic subunit of type 1 serine/threonine protein phosphatase, involved in many processes including glycogen metabolism, sporulation, and mitosis; interacts with multiple regulatory subunits; predominantly isolated with Sds22p ORF Verified inviable YER136W S000000938 GDI1 GDP dissociation inhibitor, regulates vesicle traffic in secretory pathways by regulating the dissociation of GDP from the Sec4/Ypt/rab family of GTP binding proteins ORF Verified inviable YER146W S000000948 LSM5 Lsm (Like Sm) protein; part of heteroheptameric complexes (Lsm2p-7p and either Lsm1p or 8p): cytoplasmic Lsm1p complex involved in mRNA decay; nuclear Lsm8p complex part of U6 snRNP and possibly involved in processing tRNA, snoRNA, and rRNA ORF Verified inviable YER147C S000000949 SCC4 Subunit of cohesin loading factor (Scc2p-Scc4p), a complex required for the loading of cohesin complexes onto chromosomes; involved in establishing sister chromatid cohesion during double-strand break repair via phosphorylated histone H2AX ORF Verified inviable YER148W S000000950 SPT15 TATA-binding protein, general transcription factor that interacts with other factors to form the preinitiation complex at promoters, essential for viability ORF Verified inviable YER157W S000000959 COG3 Essential component of the conserved oligomeric Golgi complex (Cog1p through Cog8p), a cytosolic tethering complex that functions in protein trafficking to mediate fusion of transport vesicles to Golgi compartments ORF Verified inviable YER159C S000000961 BUR6 Protein that forms a heterodimeric histone-fold NC2 general transcription regulator complex with Ydr1p that binds to TBP and represses RNA pol II transcription during assembly of the preinitiation complex, homologous to human NC2alpha ORF Verified inviable YER165W S000000967 PAB1 Poly(A) binding protein, part of the 3'-end RNA-processing complex, mediates interactions between the 5' cap structure and the 3' mRNA poly(A) tail, involved in control of poly(A) tail length, interacts with translation factor eIF-4G ORF Verified inviable YER168C S000000970 CCA1 ATP (CTP):tRNA-specific tRNA nucleotidyltransferase; different forms targeted to the nucleus, cytosol, and mitochondrion are generated via the use of multiple transcriptional and translational start sites ORF Verified inviable YER171W S000000973 RAD3 5' to 3' DNA helicase, involved in nucleotide excision repair and transcription; subunit of RNA polymerase II transcription initiation factor TFIIH; subunit of Nucleotide Excision Repair Factor 3 (NEF3); homolog of human XPD protein ORF Verified inviable YER172C S000000974 BRR2 RNA-dependent ATPase RNA helicase involved in the facilitation and disruption of snRNA interactions, required for disruption of U4/U6 base-pairing in native snRNPs to activate the spliceosome for catalysis ORF Verified inviable YFL002C S000001894 SPB4 Putative ATP-dependent RNA helicase, nucleolar protein required for synthesis of 60S ribosomal subunits at a late step in the pathway; sediments with 66S pre-ribosomes in sucrose gradients ORF Verified inviable YFL005W S000001889 SEC4 Secretory vesicle-associated Rab GTPase essential for exocytosis; associates with the exocyst component Sec15p and may regulate polarized delivery of transport vesicles to the exocyst at the plasma membrane ORF Verified inviable YFL008W S000001886 SMC1 Subunit of the multiprotein cohesin complex, essential protein involved in chromosome segregation and in double-strand DNA break repair; SMC chromosomal ATPase family member, binds DNA with a preference for DNA with secondary structure ORF Verified inviable YFL009W S000001885 CDC4 F-box protein required for G1/S and G2/M transition, associates with Skp1p and Cdc53p to form a complex, SCFCdc4, which acts as ubiquitin-protein ligase directing ubiquitination of the phosphorylated CDK inhibitor Sic1p ORF Verified inviable YFL017C S000001877 GNA1 Evolutionarily conserved glucosamine-6-phosphate acetyltransferase required for multiple cell cycle events including passage through START, DNA synthesis, and mitosis; involved in UDP-N-acetylglucosamine synthesis, forms GlcNAc6P from AcCoA ORF Verified inviable YFL017W-A S000002965 SMX2 Core Sm protein Sm G; part of heteroheptameric complex (with Smb1p, Smd1p, Smd2p, Smd3p, Sme1p, and Smx3p) that is part of the spliceosomal U1, U2, U4, and U5 snRNPs; homolog of human Sm G ORF Verified inviable YFL022C S000001872 FRS2 Alpha subunit of cytoplasmic phenylalanyl-tRNA synthetase, forms a tetramer with Frs1p to form active enzyme; evolutionarily distant from mitochondrial phenylalanyl-tRNA synthetase based on protein sequence, but substrate binding is similar ORF Verified inviable YFL024C S000001870 EPL1 Component of NuA4, which is an essential histone H4/H2A acetyltransferase complex; homologous to Drosophila Enhancer of Polycomb ORF Verified inviable YFL029C S000001865 CAK1 Cyclin-dependent kinase-activating kinase required for passage through the cell cycle, phosphorylates and activates Cdc28p; nucleotide-binding pocket differs significantly from those of most other protein kinases ORF Verified inviable YFL034C-B S000001859 MOB2 Component of the RAM signaling network, localizes and activates the Ace2p in the daughter cell nucleus to direct daughter cell-specific transcription of several genes involved in cell separation; Mob1p-like protein ORF Verified inviable YFL037W S000001857 TUB2 Beta-tubulin; associates with alpha-tubulin (Tub1p and Tub3p) to form tubulin dimer, which polymerizes to form microtubules ORF Verified inviable YFL038C S000001856 YPT1 Ras-like small GTPase, involved in the ER-to-Golgi step of the secretory pathway; complex formation with the Rab escort protein Mrs6p is required for prenylation of Ypt1p by protein geranylgeranyltransferase type II (Bet2p-Bet4p) ORF Verified inviable YFL039C S000001855 ACT1 Actin, structural protein involved in cell polarization, endocytosis, and other cytoskeletal functions ORF Verified inviable YFL045C S000001849 SEC53 Phosphomannomutase, involved in synthesis of GDP-mannose and dolichol-phosphate-mannose; required for folding and glycosylation of secretory proteins in the ER lumen ORF Verified inviable YFR002W S000001898 NIC96 Component of the nuclear pore complex, required for nuclear pore formation; forms a subcomplex with Nsp1p, Nup57p, and Nup49p ORF Verified inviable YFR003C S000001899 YPI1 Inhibitor of the type I protein phosphatase Glc7p, which is involved in regulation of a variety of metabolic processes; overproduction causes decreased cellular content of glycogen ORF Verified inviable YFR004W S000001900 RPN11 Metalloprotease subunit of the 19S regulatory particle of the 26S proteasome lid; couples the deubiquitination and degradation of proteasome substrates ORF Verified inviable YFR005C S000001901 SAD1 Conserved zinc-finger domain protein involved in pre-mRNA splicing, required for assembly of U4 snRNA into the U4/U6 particle ORF Verified inviable YFR027W S000001923 ECO1 Acetyltransferase required for the establishment of sister chromatid cohesion during DNA replication, but not for its maintenance during G2 and M phases; also required for postreplicative double-strand break repair; interacts with Chl1p ORF Verified inviable YFR028C S000001924 CDC14 Protein phosphatase required for mitotic exit; located in the nucleolus until liberated by the FEAR and Mitotic Exit Network in anaphase, enabling it to act on key substrates to effect a decrease in CDK/B-cyclin activity and mitotic exit ORF Verified inviable YFR029W S000001925 PTR3 Component of the SPS plasma membrane amino acid sensor system (Ssy1p-Ptr3p-Ssy5p), which senses external amino acid concentration and transmits intracellular signals that result in regulation of expression of amino acid permease genes ORF Verified inviable YFR031C S000001927 SMC2 Component of the condensin complex, essential SMC chromosomal ATPase family member that forms a complex with Smc4p to form the active ATPase; Smc2p/Smc4p complex binds DNA, possibly in the cleft formed by the coiled-coil of the folded dimer ORF Verified inviable YFR037C S000001933 RSC8 One of 15 subunits of the 'Remodel the Structure of Chromatin' (RSC) complex; essential for viability and mitotic growth; homolog of SWI/SNF subunit Swi3p, but unlike Swi3p, does not activate transcription of reporters ORF Verified inviable YFR042W S000001938 Protein required for cell viability ORF Uncharacterized inviable YFR050C S000001946 PRE4 20S proteasome beta-type subunit ORF Verified inviable YFR051C S000001947 RET2 Delta subunit of the coatomer complex (COPI), which coats Golgi-derived transport vesicles; involved in retrograde transport between Golgi and ER ORF Verified inviable YFR052W S000001948 RPN12 Subunit of the 19S regulatory particle of the 26S proteasome lid; synthetically lethal with RPT1, which is an ATPase component of the 19S regulatory particle; physically interacts with Nob1p and Rpn3p ORF Verified inviable YGL001C S000002969 ERG26 C-3 sterol dehydrogenase, catalyzes the second of three steps required to remove two C-4 methyl groups from an intermediate in ergosterol biosynthesis ORF Verified inviable YGL008C S000002976 PMA1 Plasma membrane H+-ATPase, pumps protons out of the cell; major regulator of cytoplasmic pH and plasma membrane potential; part of the P2 subgroup of cation-transporting ATPases ORF Verified inviable YGL011C S000002979 SCL1 Alpha subunit of the 20S core complex of the 26S proteasome involved in the degradation of ubiquitinated substrates; essential for growth; detected in the mitochondria ORF Verified inviable YGL018C S000002986 JAC1 Specialized J-protein that functions with Hsp70 in Fe-S cluster biogenesis in mitochondria, involved in iron metabolism; contains a J domain typical to J-type chaperones; localizes to the mitochondrial matrix ORF Verified inviable YGL022W S000002990 STT3 Subunit of the oligosaccharyltransferase complex of the ER lumen, which catalyzes asparagine-linked glycosylation of newly synthesized proteins; forms a subcomplex with Ost3p and Ost4p and is directly involved in catalysis ORF Verified inviable YGL030W S000002998 RPL30 Protein component of the large (60S) ribosomal subunit, has similarity to rat L30 ribosomal protein; involved in pre-rRNA processing in the nucleolus; autoregulates splicing of its transcript ORF Verified inviable YGL040C S000003008 HEM2 Delta-aminolevulinate dehydratase, a homo-octameric enzyme, catalyzes the conversion of delta-aminolevulinic acid to porphobilinogen, the second step in the heme biosynthetic pathway; localizes to both the cytoplasm and nucleus ORF Verified inviable YGL044C S000003012 RNA15 Cleavage and polyadenylation factor I (CF I) component involved in cleavage and polyadenylation of mRNA 3' ends; interacts with the A-rich polyadenylation signal in complex with Rna14p and Hrp1p ORF Verified inviable YGL047W S000003015 ALG13 Catalytic component of UDP-GlcNAc transferase, required for the second step of dolichyl-linked oligosaccharide synthesis; anchored to the ER membrane via interaction with Alg14p; similar to bacterial and human glycosyltransferases ORF Verified inviable YGL048C S000003016 RPT6 One of six ATPases of the 19S regulatory particle of the 26S proteasome involved in the degradation of ubiquitinated substrates; bound by ubiquitin-protein ligases Ubr1p and Ufd4p; localized mainly to the nucleus throughout the cell cycle ORF Verified inviable YGL055W S000003023 OLE1 Fatty acid desaturase, required for monounsaturated fatty acid synthesis and for normal distribution of mitochondria ORF Verified inviable YGL061C S000003029 DUO1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segregation; is transferred to the kinetochore prior to mitosis ORF Verified inviable YGL065C S000003033 ALG2 Presumed early mannosyltransferase involved in the N-linked glycosylation pathway; alg2 mutants exhibit temperature-sensitive growth and abnormal accumulation of the lipid-linked oligosaccharide Man2GlcNAc2-PP-Dol ORF Verified inviable YGL068W S000003036 MNP1 Protein associated with the mitochondrial nucleoid; putative mitochondrial ribosomal protein with similarity to E. coli L7/L12 ribosomal protein; required for normal respiratory growth ORF Verified inviable YGL069C S000003037 Dubious open reading frame, unlikely to encode a protein; not conserved in closely related Saccharomyces species; 92% of ORF overlaps the uncharacterized ORF YGL068W; deletion in cyr1 mutant results in loss of stress resistance ORF Dubious inviable YGL073W S000003041 HSF1 Trimeric heat shock transcription factor, activates multiple genes in response to hyperthermia; recognizes variable heat shock elements (HSEs) consisting of inverted NGAAN repeats; constitutively DNA-bound; posttranslationally regulated ORF Verified inviable YGL074C S000003042 Hypothetical protein; open reading frame overlaps 5' end of essential HSF1 gene encoding heat shock transcription factor ORF Dubious inviable YGL075C S000003043 MPS2 Essential membrane protein localized at the nuclear envelope and spindle pole body (SPB), required for insertion of the newly duplicated SPB into the nuclear envelope; potentially phosphorylated by Cdc28p ORF Verified inviable YGL091C S000003059 NBP35 Essential nuclear protein, evolutionarily conserved putative ATPase; exhibits genetic interaction with CDC2 encoding the catalytic subunit of DNA polymerase delta ORF Verified inviable YGL092W S000003060 NUP145 Essential nucleoporin, catalyzes its own cleavage in vivo to generate a C-terminal fragment that assembles into the Nup84p subcomplex of the nuclear pore complex, and an N-terminal fragment of unknown function that is homologous to Nup100p ORF Verified inviable YGL093W S000003061 SPC105 Protein required for accurate chromosome segregation, localizes to the nuclear side of the spindle pole body; forms a complex with Ydr532cp ORF Verified inviable YGL097W S000003065 SRM1 Nucleotide exchange factor for Gsp1p, localizes to the nucleus, required for nucleocytoplasmic trafficking of macromolecules; potentially phosphorylated by Cdc28p ORF Verified inviable YGL098W S000003066 USE1 Essential SNARE protein localized to the ER, involved in retrograde traffic from the Golgi to the ER; forms a complex with the SNAREs Sec22p, Sec20p and Ufe1p ORF Verified inviable YGL099W S000003067 LSG1 Putative GTPase involved in 60S ribosomal subunit biogenesis; required for the release of Nmd3p from 60S subunits in the cytoplasm ORF Verified inviable YGL102C S000003070 Hypothetical protein; open reading frame overlaps 3' end of essential RPL28 gene encoding a large subunit ribosomal protein ORF Dubious inviable YGL103W S000003071 RPL28 Ribosomal protein L29 of the large (60S) ribosomal subunit, has similarity to E. coli L15 and rat L27a ribosomal proteins; may have peptidyl transferase activity; can mutate to cycloheximide resistance ORF Verified inviable YGL111W S000003079 NSA1 Constituent of 66S pre-ribosomal particles, involved in 60S ribosomal subunit biogenesis ORF Verified inviable YGL112C S000003080 TAF6 Subunit (60 kDa) of TFIID and SAGA complexes, involved in transcription initiation of RNA polymerase II and in chromatin modification, similar to histone H4 ORF Verified inviable YGL113W S000003081 SLD3 Protein involved in the initiation of DNA replication, required for proper assembly of replication proteins at the origins of replication; interacts with Cdc45p ORF Verified inviable YGL116W S000003084 CDC20 Cell-cycle regulated activator of anaphase-promoting complex/cyclosome (APC/C), which is required for metaphase/anaphase transition; directs ubiquitination of mitotic cyclins, Pds1p, and other anaphase inhibitors; potential Cdc28p substrate ORF Verified inviable YGL120C S000003088 PRP43 RNA helicase in the DEAH-box family, involved in release of the lariat-intron from the spliceosome ORF Verified inviable YGL122C S000003090 NAB2 Nuclear polyadenylated RNA-binding protein; autoregulates mRNA levels; related to human hnRNPs; has nuclear localization signal sequence that binds to Kap104p; required for poly(A) tail length control and nuclear mRNA export ORF Verified inviable YGL123W S000003091 RPS2 Protein component of the small (40S) subunit, essential for control of translational accuracy; has similarity to E. coli S5 and rat S2 ribosomal proteins ORF Verified inviable YGL128C S000003096 CWC23 Component of a complex containing Cef1p, putatively involved in pre-mRNA splicing; has similarity to E. coli DnaJ and other DnaJ-like proteins and to S. pombe Cwf23p ORF Verified inviable YGL130W S000003098 CEG1 Alpha (guanylyltransferase) subunit of the mRNA capping enzyme, a heterodimer (the other subunit is CET1, an RNA 5'-triphophatase) involved in adding the 5' cap to mRNA; the mammalian enzyme is a single bifunctional polypeptide ORF Verified inviable YGL137W S000003105 SEC27 Essential beta'-coat protein of the COPI coatomer, involved in ER-to-Golgi and Golgi-to-ER transport; contains WD40 domains that mediate cargo selective interactions; 45% sequence identity to mammalian beta'-COP ORF Verified inviable YGL142C S000003110 GPI10 Integral membrane protein involved in glycosylphosphatidylinositol (GPI) anchor synthesis; putative alpha 1,2 mannosyltransferase required for addition of the third mannose onto the GPI core structure; human PIG-Bp is a functional homolog ORF Verified inviable YGL145W S000003113 TIP20 Peripheral membrane protein required for fusion of COPI vesicles with the ER, prohibits back-fusion of COPII vesicles with the ER, may act as a sensor for vesicles at the ER membrane ORF Verified inviable YGL150C S000003118 INO80 ATPase that forms a large complex, containing actin and several actin-related proteins, that has chromatin remodeling activity and 3' to 5' DNA helicase activity in vitro; shows similarity to the Snf2p family of ATPases ORF Verified inviable YGL155W S000003123 CDC43 Beta subunit of geranylgeranyltransferase type I, catalyzes geranylgeranylation to the cysteine residue in proteins containing a C-terminal CaaX sequence ending in Leu or Phe; has substrates important for morphogenesis ORF Verified inviable YGL169W S000003137 SUA5 Protein required for respiratory growth; null mutation suppresses the Cyc1p translation defect caused by the presence of an aberrant ATG codon upstream of the correct start ORF Verified inviable YGL171W S000003139 ROK1 ATP-dependent RNA helicase of the DEAD box family; required for 18S rRNA synthesis ORF Verified inviable YGL172W S000003140 NUP49 Subunit of the Nsp1p-Nup57p-Nup49p-Nic96p subcomplex of the nuclear pore complex (NPC), required for nuclear export of ribosomes ORF Verified inviable YGL201C S000003169 MCM6 Protein involved in DNA replication; component of the Mcm2-7 hexameric complex that binds chromatin as a part of the pre-replicative complex ORF Verified inviable YGL207W S000003175 SPT16 Subunit of the heterodimeric FACT complex (Spt16p-Pob3p), facilitates RNA Polymerase II transcription elongation through nucleosomes by destabilizing and then reassembling nucleosome structure ORF Verified inviable YGL225W S000003193 VRG4 Golgi GDP-mannose transporter; regulates Golgi function and glycosylation in Golgi ORF Verified inviable YGL233W S000003202 SEC15 Essential 113kDa subunit of the exocyst complex (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p, and Exo84p), which mediates polarized targeting of vesicles to active sites of exocytosis; Sec15p associates with Sec4p and vesicles ORF Verified inviable YGL238W S000003207 CSE1 Nuclear envelope protein that mediates the nuclear export of importin alpha (Srp1p), homolog of metazoan CAS protein, required for accurate chromosome segregation ORF Verified inviable YGL239C S000003208 Hypothetical protein; open reading frame overlaps 5' end of essential CSE1 gene encoding a nuclear envelope protein involved in nuclear export ORF Dubious inviable YGL245W S000003214 GUS1 Glutamyl-tRNA synthetase (GluRS), forms a complex with methionyl-tRNA synthetase (Mes1p) and Arc1p; complex formation increases the catalytic efficiency of both tRNA synthetases and ensures their correct localization to the cytoplasm ORF Verified inviable YGL247W S000003216 BRR6 Essential nuclear envelope integral membrane protein required for nuclear transport; depletion alters nucleoporin distribution and nuclear envelope morphology, suggesting a role in the spatial organization of nuclear pores ORF Verified inviable YGR002C S000003234 SWC4 Protein of unknown function, component of the Swr1p complex that incorporates Htz1p into chromatin; component of the NuA4 histone acetyltransferase complex ORF Verified inviable YGR005C S000003237 TFG2 TFIIF (Transcription Factor II) middle subunit; involved in both transcription initiation and elongation of RNA polymerase II; homologous to human RAP30 ORF Verified inviable YGR009C S000003241 SEC9 t-SNARE protein important for fusion of secretory vesicles with the plasma membrane; similar to but not functionally redundant with Spo20p; SNAP-25 homolog ORF Verified inviable YGR013W S000003245 SNU71 Component of U1 snRNP required for mRNA splicing via spliceosome; yeast specific, no metazoan counterpart ORF Verified inviable YGR024C S000003256 THG1 tRNAHis guanylyltransferase, adds a guanosine residue to the 5' end of tRNAHis after transcription and RNase P cleavage; couples nuclear division and migration to cell budding and cytokinesis; essential enzyme conserved among eukaryotes ORF Verified inviable YGR029W S000003261 ERV1 Flavin-linked sulfhydryl oxidase localized to the mitochondrial intermembrane space, has a role in the maturation of cytosolic iron-sulfur proteins; ortholog of human hepatopoietin (ALR) ORF Verified inviable YGR030C S000003262 POP6 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends ORF Verified inviable YGR046W S000003278 Putative protein of unknown function; mRNA is targeted to the bud via the mRNA transport system involving She2p; deletion mutant is inviable ORF Uncharacterized inviable YGR047C S000003279 TFC4 One of six subunits of the RNA polymerase III transcription initiation factor complex (TFIIIC); part of the TauA domain of TFIIIC that binds BoxA DNA promoter sites of tRNA and similar genes; has TPR motifs; human homolog is TFIIIC-102 ORF Verified inviable YGR048W S000003280 UFD1 Protein that interacts with Cdc48p and Npl4p, involved in recognition of polyubiquitinated proteins and their presentation to the 26S proteasome for degradation; involved in transporting proteins from the ER to the cytosol ORF Verified inviable YGR060W S000003292 ERG25 C-4 methyl sterol oxidase, catalyzes the first of three steps required to remove two C-4 methyl groups from an intermediate in ergosterol biosynthesis; mutants accumulate the sterol intermediate 4,4-dimethylzymosterol ORF Verified inviable YGR065C S000003297 VHT1 High-affinity plasma membrane H+-biotin (vitamin H) symporter; mutation results in fatty acid auxotrophy; 12 transmembrane domain containing major facilitator subfamily member; mRNA levels negatively regulated by iron deprivation and biotin ORF Verified inviable YGR073C S000003305 Hypothetical protein; open reading frame extensively overlaps essential SMD1 gene encoding a U6 snRNP protein ORF Dubious inviable YGR074W S000003306 SMD1 Core Sm protein Sm D1; part of heteroheptameric complex (with Smb1p, Smd2p, Smd3p, Sme1p, Smx3p, and Smx2p) that is part of the spliceosomal U1, U2, U4, and U5 snRNPs; homolog of human Sm D1 ORF Verified inviable YGR075C S000003307 PRP38 Unique component of the U4/U6.U5 tri-snRNP particle, dispensable for spliceosome assembly, but required for conformational changes which lead to catalytic activation of the spliceosome ORF Verified inviable YGR082W S000003314 TOM20 Component of the TOM (translocase of outer membrane) complex responsible for recognition and initial import steps for all mitochondrially directed proteins; acts as a receptor for incoming precursor proteins ORF Verified inviable YGR083C S000003315 GCD2 Delta subunit of the translation initiation factor eIF2B, the guanine-nucleotide exchange factor for eIF2; activity subsequently regulated by phosphorylated eIF2; first identified as a negative regulator of GCN4 expression ORF Verified inviable YGR090W S000003322 UTP22 Possible U3 snoRNP protein involved in maturation of pre-18S rRNA, based on computational analysis of large-scale protein-protein interaction data ORF Uncharacterized inviable YGR091W S000003323 PRP31 Splicing factor, component of the U4/U6-U5 snRNP complex ORF Verified inviable YGR094W S000003326 VAS1 Mitochondrial and cytoplasmic valyl-tRNA synthetase ORF Verified inviable YGR095C S000003327 RRP46 Protein involved in rRNA processing; component of the exosome 3->5 exonuclease complex ORF Verified inviable YGR098C S000003330 ESP1 Separase with cysteine protease activity (related to caspases) that promotes sister chromatid separation by mediating dissociation of the cohesin Scc1p from chromatin; inhibited by Pds1p ORF Verified inviable YGR099W S000003331 TEL2 Essential DNA-binding protein specific to single-stranded yeast telomeric DNA repeats, required for telomere length regulation and telomere position effect ORF Verified inviable YGR103W S000003335 NOP7 Nucleolar protein involved in rRNA processing and 60S ribosomal subunit biogenesis; constituent of several different pre-ribosomal particles; required for exit from G0 and the initiation of cell proliferation ORF Verified inviable YGR113W S000003345 DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segregation; Ipl1p target for regulating kinetochore-MT attachments ORF Verified inviable YGR114C S000003346 Hypothetical protein; open reading frame overlaps 5' end of essential SPT6 gene involved in nucleosome disassembly and reassembly during transcription ORF Dubious inviable YGR115C S000003347 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; partially overlaps the verified and essential ORF SPT6/YGR115C ORF Dubious inviable YGR116W S000003348 SPT6 Essential protein that interacts with histones and is involved in nucleosome disassembly and reassembly during transcription elongation ORF Verified inviable YGR119C S000003351 NUP57 Essential subunit of the nuclear pore complex (NPC), functions as the organizing center of an NPC subcomplex containing Nsp1p, Nup49p, Nup57p, and Nic96p ORF Verified inviable YGR120C S000003352 COG2 Essential component of the conserved oligomeric Golgi complex (Cog1p through Cog8p), a cytosolic tethering complex that functions in protein trafficking to mediate fusion of transport vesicles to Golgi compartments ORF Verified inviable YGR128C S000003360 UTP8 Nucleolar protein required for export of tRNAs from the nucleus; also copurifies with the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YGR140W S000003372 CBF2 Essential kinetochore protein, component of the CBF3 multisubunit complex that binds to the CDEIII region of the centromere; Cbf2p also binds to the CDEII region possibly forming a different multimeric complex, ubiquitinated in vivo ORF Verified inviable YGR145W S000003377 ENP2 Essential nucleolar protein of unknown function; contains WD repeats, interacts with Mpp10p and Bfr2p, and has homology to Spb1p ORF Uncharacterized inviable YGR147C S000003379 NAT2 N alpha-acetyl-transferase, transfers acetyl group from acetyl coenzyme A to the N-terminal methionine residues of proteins ORF Verified inviable YGR156W S000003388 PTI1 Pta1p Interacting protein ORF Verified inviable YGR158C S000003390 MTR3 3'5' exoribonuclease, exosome subunit; nucleolar protein involved in export of mRNA and ribosomal subunits; homologous to the E. coli exonuclease RNase PH ORF Verified inviable YGR172C S000003404 YIP1 Integral membrane protein required for the biogenesis of ER-derived COPII transport vesicles; interacts with Yif1p and Yos1p; localizes to the Golgi, the ER, and COPII vesicles ORF Verified inviable YGR175C S000003407 ERG1 Squalene epoxidase, catalyzes the epoxidation of squalene to 2,3-oxidosqualene; plays an essential role in the ergosterol-biosynthesis pathway and is the specific target of the antifungal drug terbinafine ORF Verified inviable YGR179C S000003411 OKP1 Outer kinetochore protein, required for accurate mitotic chromosome segregation; component of the kinetochore sub-complex COMA (Ctf19p, Okp1p, Mcm21p, Ame1p) that functions as a platform for kinetochore assembly ORF Verified inviable YGR185C S000003417 TYS1 Cytoplasmic tyrosyl-tRNA synthetase, class I aminoacyl-tRNA synthetase that aminoacylates tRNA(Tyr), required for cytoplasmic protein synthesis, interacts with positions 34 and 35 of the anticodon of tRNATyr ORF Verified inviable YGR186W S000003418 TFG1 TFIIF (Transcription Factor II) largest subunit; involved in both transcription initiation and elongation of RNA polymerase II; homologous to human RAP74 ORF Verified inviable YGR190C S000003422 Hypothetical protein; open reading frame overlaps 5' end of essential HIP1 gene encoding histidine permease ORF Dubious inviable YGR191W S000003423 HIP1 High-affinity histidine permease, also involved in the transport of manganese ions ORF Verified inviable YGR195W S000003427 SKI6 3'-to-5' phosphorolytic exoribonuclease that is a subunit of the exosome; required for 3' processing of the 5.8S rRNA; involved in 3' to 5' mRNA degradation and translation inhibition of non-poly(A) mRNAs ORF Verified inviable YGR198W S000003430 Putative protein of unknown function; green fluorescent protein (GFP)-fusion protein localizes to the cytoplasm in a punctate pattern; YGR198W is an essential gene ORF Uncharacterized inviable YGR211W S000003443 ZPR1 Essential protein with two zinc fingers, present in the nucleus of growing cells but relocates to the cytoplasm in starved cells via a process mediated by Cpr1p; binds to translation elongation factor eEF-1 (Tef1p) ORF Verified inviable YGR216C S000003448 GPI1 Membrane protein involved in the synthesis of N-acetylglucosaminyl phosphatidylinositol (GlcNAc-PI), the first intermediate in the synthesis of glycosylphosphatidylinositol (GPI) anchors; human and mouse GPI1p are functional homologs ORF Verified inviable YGR218W S000003450 CRM1 Major karyopherin, involved in export of proteins, RNAs, and ribosomal subunits from the nucleus ORF Verified inviable YGR245C S000003477 SDA1 Highly conserved nuclear protein required for actin cytoskeleton organization and passage through Start, plays a critical role in G1 events, binds Nap1p, also involved in 60S ribosome biogenesis ORF Verified inviable YGR246C S000003478 BRF1 TFIIIB B-related factor, one of three subunits of RNA polymerase III transcription initiation factor TFIIIB, binds TFIIIC and TBP and recruits RNA pol III to promoters, amino-terminal half is homologous to TFIIB ORF Verified inviable YGR251W S000003483 Putative protein of unknown function; deletion mutant has defects in pre-rRNA processing; green fluorescent protein (GFP)-fusion protein localizes to both the nucleus and the nucleolus; YGR251W is an essential gene ORF Uncharacterized inviable YGR253C S000003485 PUP2 Alpha subunit of the 20S proteasome involved in ubiquitin-dependent catabolism; human homolog is subunit zeta ORF Verified inviable YGR264C S000003496 MES1 Methionyl-tRNA synthetase, forms a complex with glutamyl-tRNA synthetase (Gus1p) and Arc1p, which increases the catalytic efficiency of both tRNA synthetases; also has a role in nuclear export of tRNAs ORF Verified inviable YGR265W S000003497 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; partially overlaps the verified ORF MES1/YGR264C, which encodes methionyl-tRNA synthetase ORF Dubious inviable YGR267C S000003499 FOL2 GTP-cyclohydrolase I, catalyzes the first step in the folic acid biosynthetic pathway ORF Verified inviable YGR274C S000003506 TAF1 TFIID subunit (145 kDa), involved in RNA polymerase II transcription initiation, has histone acetyltransferase activity, involved in promoter binding and G1/S progression ORF Verified inviable YGR277C S000003509 Putative protein of unknown function; sequence similarity to Pantetheine-phosphate adenylyltransferase (PPAT); YGR277C is an essential gene ORF Uncharacterized inviable YGR278W S000003510 CWC22 Essential protein, component of a complex containing Cef1p, has similarity to S. pombe Cwf22p; putative spliceosomal component, based on computational analysis of large-scale protein-protein interaction data ORF Verified inviable YGR280C S000003512 PXR1 Essential protein involved in rRNA and snoRNA maturation; competes with TLC1 RNA for binding to Est2p, suggesting a role in regulation of telomerase; human homolog inhibits telomerase; contains a G-patch RNA interacting domain ORF Verified inviable YHL015W S000001007 RPS20 Protein component of the small (40S) ribosomal subunit; overproduction suppresses mutations affecting RNA polymerase III-dependent transcription; has similarity to E. coli S10 and rat S20 ribosomal proteins ORF Verified inviable YHR005C-A S000003530 MRS11 Essential protein of the mitochondrial intermembrane space, forms a complex with Tim9p (TIM10 complex) that mediates insertion of hydrophobic proteins at the inner membrane, has homology to Mrs5p, which is also involved in this process ORF Verified inviable YHR007C S000001049 ERG11 Lanosterol 14-alpha-demethylase, catalyzes the C-14 demethylation of lanosterol to form 4,4''-dimethyl cholesta-8,14,24-triene-3-beta-ol in the ergosterol biosynthesis pathway; member of the cytochrome P450 family ORF Verified inviable YHR019C S000001061 DED81 Cytosolic asparaginyl-tRNA synthetase, required for protein synthesis, catalyzes the specific attachment of asparagine to its cognate tRNA ORF Verified inviable YHR020W S000001062 Putative protein of unknown function, has similarity to proline-tRNA ligase; YHR020W is an essential gene ORF Uncharacterized inviable YHR023W S000001065 MYO1 Type II myosin heavy chain, required for wild-type cytokinesis and cell separation; localizes to the actomyosin ring; binds to myosin light chains Mlc1p and Mlc2p through its IQ1 and IQ2 motifs respectively ORF Verified inviable YHR024C S000001066 MAS2 Larger subunit of the mitochondrial processing protease, essential processing enzyme that cleaves the N-terminal targeting sequences from mitochondrially imported proteins ORF Verified inviable YHR036W S000001078 BRL1 Essential nuclear envelope integral membrane protein identified as a suppressor of a cold-sensitive mutant of CRM1, a karyopherin; homologous to and interacts with Brr6p, which is a nuclear envelope protein involved in nuclear export ORF Verified inviable YHR040W S000001082 BCD1 Essential protein required for the accumulation of box C/D snoRNA ORF Verified inviable YHR042W S000001084 NCP1 NADP-cytochrome P450 reductase; involved in ergosterol biosynthesis; associated and coordinately regulated with Erg11p ORF Verified inviable YHR058C S000001100 MED6 Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; essential for transcriptional regulation ORF Verified inviable YHR062C S000001104 RPP1 Subunit of both RNase MRP, which cleaves pre-rRNA, and nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends ORF Verified inviable YHR065C S000001107 RRP3 Protein involved in rRNA processing; required for maturation of the 35S primary transcript of pre-rRNA and for cleavage leading to mature 18S rRNA; homologous to eIF-4a, which is a DEAD box RNA-dependent ATPase with helicase activity ORF Verified inviable YHR068W S000001110 DYS1 Deoxyhypusine synthase, catalyzes formation of deoxyhypusine, the first step in hypusine biosynthesis; triggers posttranslational hypusination of translation elongation factor eIF-5A and regulates its intracellular levels; tetrameric ORF Verified inviable YHR069C S000001111 RRP4 Protein involved in rRNA processing; component of the exosome 3->5 exonuclease complex with Rrp41p, Rrp42p, Rrp43p and Dis3p ORF Verified inviable YHR070W S000001112 TRM5 tRNA(m(1)G37)methyltransferase, methylates a tRNA base adjacent to the anticodon that has a role in prevention of frameshifting; highly conserved across Archaea, Bacteria, and Eukarya ORF Verified inviable YHR072W S000001114 ERG7 Lanosterol synthase, an essential enzyme that catalyzes the cyclization of squalene 2,3-epoxide, a step in ergosterol biosynthesis ORF Verified inviable YHR074W S000001116 QNS1 Glutamine-dependent NAD(+) synthetase, essential for the formation of NAD(+) from nicotinic acid adenine dinucleotide ORF Verified inviable YHR083W S000001125 SAM35 Essential component of the sorting and assembly machinery (SAM complex or TOB complex) of the mitochondrial outer membrane, which binds precursors of beta-barrel proteins and facilitates their insertion into the outer membrane ORF Verified inviable YHR085W S000001127 IPI1 Protein of unknown function, essential for viability, may be involved in rRNA processing ORF Verified inviable YHR088W S000001130 RPF1 Nucleolar protein involved in the assembly of the large ribosomal subunit; constituent of 66S pre-ribosomal particles; contains a sigma(70)-like motif, which is thought to bind RNA ORF Verified inviable YHR101C S000001143 BIG1 Integral membrane protein of the endoplasmic reticulum, required for normal content of cell wall beta-1,6-glucan ORF Verified inviable YHR107C S000001149 CDC12 Component of the septin ring of the mother-bud neck that is required for cytokinesis; septins recruit proteins to the neck and can act as a barrier to diffusion at the membrane, and they comprise the 10nm filaments seen with EM ORF Verified inviable YHR118C S000001160 ORC6 Subunit of the origin recognition complex, which directs DNA replication by binding to replication origins and is also involved in transcriptional silencing; may be phosphorylated by Cdc28p ORF Verified inviable YHR122W S000001164 Putative protein of unknown function; green fluorescent protein (GFP)-fusion protein localizes to the cytoplasm; may be involved in transcription; YHR122W is an essential gene ORF Uncharacterized inviable YHR143W-A S000001185 RPC10 RNA polymerase subunit, found in RNA polymerase complexes I, II, and III ORF Verified inviable YHR148W S000001191 IMP3 Component of the SSU processome, which is required for pre-18S rRNA processing, essential protein that interacts with Mpp10p and mediates interactions of Imp4p and Mpp10p with U3 snoRNA ORF Verified inviable YHR164C S000001207 DNA2 Essential tripartite DNA replication factor with single-stranded DNA-dependent ATPase, ATP-dependent nuclease, and helicase activities; required for Okazaki fragment processing; involved in DNA repair pathways; potential Cdc28p substrate ORF Verified inviable YHR166C S000001209 CDC23 Subunit of the anaphase-promoting complex/cyclosome (APC/C), which is a ubiquitin-protein ligase required for degradation of anaphase inhibitors, including mitotic cyclins, during the metaphase/anaphase transition ORF Verified inviable YHR170W S000001213 NMD3 Protein involved in nuclear export of the large ribosomal subunit; acts as a Crm1p-dependent adapter protein for export of nascent ribosomal subunits through the nuclear pore complex ORF Verified inviable YHR172W S000001215 SPC97 Component of the microtubule-nucleating Tub4p (gamma-tubulin) complex; interacts with Spc110p at the spindle pole body (SPB) inner plaque and with Spc72p at the SPB outer plaque ORF Verified inviable YHR186C S000001229 KOG1 Subunit of TORC1, a rapamycin-sensitive complex involved in growth control that contains Tor1p or Tor2p, Lst8p and Tco89p; contains four HEAT repeats and seven WD-40 repeats; may act as a scaffold protein to couple TOR and its effectors ORF Verified inviable YHR188C S000001231 GPI16 Transmembrane protein subunit of the glycosylphosphatidylinositol transamidase complex that adds GPIs to newly synthesized proteins; human PIG-Tp homolog ORF Verified inviable YHR190W S000001233 ERG9 Farnesyl-diphosphate farnesyl transferase (squalene synthase), joins two farnesyl pyrophosphate moieties to form squalene in the sterol biosynthesis pathway ORF Verified inviable YHR196W S000001239 UTP9 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YHR197W S000001240 RIX1 Essential protein involved in the processing of the ITS2 region of the rRNA locus; required for the maturation and nuclear export of the 60S ribosomal subunit ORF Verified inviable YIL003W S000001265 CFD1 Highly conserved, putative P-loop ATPase localized in the cytoplasm; has a potential role in assembly of iron-sulfur clusters in proteins ORF Verified inviable YIL004C S000001266 BET1 Type II membrane protein required for vesicular transport between the endoplasmic reticulum and Golgi complex; v-SNARE with similarity to synaptobrevins ORF Verified inviable YIL019W S000001281 FAF1 Protein required for pre-rRNA processing and 40S ribosomal subunit assembly ORF Verified inviable YIL021W S000001283 RPB3 RNA polymerase II third largest subunit B44, part of central core; similar to prokaryotic alpha subunit ORF Verified inviable YIL022W S000001284 TIM44 Peripheral mitochondrial membrane protein involved in mitochondrial protein import, tethers essential chaperone Ssc1p to the translocon channel at the matrix side of the inner membrane ORF Verified inviable YIL026C S000001288 IRR1 Subunit of the cohesin complex, which is required for sister chromatid cohesion during mitosis and meiosis and interacts with centromeres and chromosome arms, essential for viability ORF Verified inviable YIL031W S000001293 ULP2 Peptidase that deconjugates Smt3/SUMO-1 peptides from proteins, plays a role in chromosome cohesion at centromeric regions and recovery from checkpoint arrest induced by DNA damage or DNA replication defects; potential Cdc28p substrate ORF Verified inviable YIL046W S000001308 MET30 F-box protein containing five copies of the WD40 motif, controls cell cycle function, sulfur metabolism, and methionine biosynthesis as part of the ubiquitin ligase complex; interacts with and regulates Met4p, localizes within the nucleus ORF Verified inviable YIL048W S000001310 NEO1 Protein involved in the retrograde transport from the Golgi complex to the ER and the endosomal membrane traffic; putative aminophospholipid translocase; member of the highly conserved Drs2 family of P-type ATPases ORF Verified inviable YIL051C S000001313 MMF1 Mitochondrial protein involved in maintenance of the mitochondrial genome ORF Verified inviable YIL061C S000001323 SNP1 Component of U1 snRNP required for mRNA splicing via spliceosome; may interact with poly(A) polymerase to regulate polyadenylation; homolog of human U1 70K protein ORF Verified inviable YIL062C S000001324 ARC15 Subunit of the ARP2/3 complex, which is required for the motility and integrity of cortical actin patches ORF Verified inviable YIL063C S000001325 YRB2 Protein of unknown function involved in nuclear processes of the Ran-GTPase cycle; involved in nuclear protein export; contains Ran Binding Domain and FxFG repeats; interacts with Srm1p, GTP-Gsp1p, Rna1p and Crm1p; is not essential ORF Verified inviable YIL068C S000001330 SEC6 Essential 88kDa subunit of the exocyst complex, which mediates polarized targeting of secretory vesicles to active sites of exocytosis; dimeric form of Sec6p interacts with Sec9p in vitro and inhibits t-SNARE assembly ORF Verified inviable YIL075C S000001337 RPN2 Subunit of the 26S proteasome, substrate of the N-acetyltransferase Nat1p ORF Verified inviable YIL078W S000001340 THS1 Threonyl-tRNA synthetase, essential cytoplasmic protein ORF Verified inviable YIL083C S000001345 Homolog to human PPCS ORF Uncharacterized inviable YIL091C S000001353 Protein required for cell viability ORF Uncharacterized inviable YIL104C S000001366 SHQ1 Essential nuclear protein, required for accumulation of box H/ACA snoRNAs and for rRNA processing; interacts with Naf1p ORF Verified inviable YIL106W S000001368 MOB1 Component of the mitotic exit network; associates with and is required for the activation and Cdc15p-dependent phosphorylation of the Dbf2p kinase; required for cytokinesis and cell separation; component of the CCR4 transcriptional complex ORF Verified inviable YIL109C S000001371 SEC24 Component of the Sec23p-Sec24p heterodimeric complex of the COPII vesicle coat; involved in ER to Golgi transport, cargo selection and autophagy; required for the binding of the Sec13 complex to ER membranes; homologous to Lst1p and Lss1p ORF Verified inviable YIL115C S000001377 NUP159 Subunit of the nuclear pore complex that is found exclusively on the cytoplasmic side, forms a subcomplex with Nup82p and Nsp1p, required for mRNA export ORF Verified inviable YIL118W S000001380 RHO3 Non-essential small GTPase of the Rho/Rac subfamily of Ras-like proteins involved in the establishment of cell polarity; GTPase activity positively regulated by the GTPase activating protein (GAP) Rgd1p ORF Verified inviable YIL126W S000001388 STH1 ATPase component of the ATP-dependent RSC chromatin remodeling complex required for kinetochore function in chromosome segregation; required for expression of early meiotic genes; essential helicase-related protein homologous to Snf2p ORF Verified inviable YIL129C S000001391 TAO3 Protein involved in cell morphogenesis and proliferation, associated with protein kinase Cbk1p; mutants activate OCH1 transcription ORF Verified inviable YIL142W S000001404 CCT2 Subunit beta of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YIL143C S000001405 SSL2 Component of the holoenzyme form of RNA polymerase transcription factor TFIIH, has DNA-dependent ATPase/helicase activity and is required, with Rad3p, for unwinding promoter DNA; involved in DNA repair; homolog of human ERCC3 ORF Verified inviable YIL144W S000001406 TID3 Component of the evolutionarily conserved kinetochore-associated Ndc80 complex (Ndc80p-Nuf2p-Spc24p-Spc25p); conserved coiled-coil protein involved in chromosome segregation, spindle checkpoint activity, kinetochore assembly and clustering ORF Verified inviable YIL147C S000001409 SLN1 Histidine kinase osmosensor that regulates a MAP kinase cascade; transmembrane protein with an intracellular kinase domain that signals to Ypd1p and Ssk1p, thereby forming a phosphorelay system similar to bacterial two-component regulators ORF Verified inviable YIL150C S000001412 MCM10 Essential, chromatin-associated protein involved in the initiation of DNA replication; required for the association of the MCM2-7 complex with replication origins ORF Verified inviable YIR006C S000001445 PAN1 Part of actin cytoskeleton-regulatory complex Pan1p-Sla1p-End3p, associates with actin patches on the cell cortex; promotes protein-protein interactions essential for endocytosis; previously thought to be a subunit of poly(A) ribonuclease ORF Verified inviable YIR008C S000001447 PRI1 Subunit of DNA primase, which is required for DNA synthesis and double-strand break repair ORF Verified inviable YIR010W S000001449 DSN1 Essential component of the MIND kinetochore complex (Mtw1p Including Nnf1p-Nsl1p-Dsn1p) which joins kinetochore subunits contacting DNA to those contacting microtubules; important for chromosome segregation ORF Verified inviable YIR011C S000001450 STS1 Protein that interacts with the karyopherin Srp1p; may have a role with Srp1p in ubiquitin-mediated protein degradation ORF Verified inviable YIR012W S000001451 SQT1 Essential protein involved in a late step of 60S ribosomal subunit assembly or modification; contains multiple WD repeats; interacts with Qsr1p in a two-hybrid assay ORF Verified inviable YIR015W S000001454 RPR2 Subunit of nuclear RNase P, which cleaves tRNA precursors to generate mature 5' ends; not shared between Rnase MRP and Rnase P, in contrast to all other Rnase P protein subunits ORF Verified inviable YIR022W S000001461 SEC11 18kDa catalytic subunit of the Signal Peptidase Complex (SPC; Spc1p, Spc2p, Spc3p, and Sec11p) which cleaves the signal sequence of proteins targeted to the endoplasmic reticulum ORF Verified inviable YJL001W S000003538 PRE3 20S proteasome beta-type subunit, responsible for cleavage after acidic residues in peptides ORF Verified inviable YJL002C S000003539 OST1 Alpha subunit of the oligosaccharyltransferase complex of the ER lumen, which catalyzes asparagine-linked glycosylation of newly synthesized proteins ORF Verified inviable YJL005W S000003542 CYR1 Adenylate cyclase, required for cAMP production and cAMP-dependent protein kinase signaling; involved in cell cycle control and glucose and nitrogen repression of sporulation ORF Verified inviable YJL008C S000003545 CCT8 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YJL009W S000003546 Hypothetical protein; open reading frame overlaps 3' end of essential CCT8 gene encoding a subunit of the cytosolic chaperonin Cct ring complex ORF Dubious inviable YJL010C S000003547 NOP9 Essential nucleolar protein required for 18S rRNA synthesis ORF Uncharacterized inviable YJL011C S000003548 RPC17 RNA polymerase III subunit C17; physically interacts with C31, C11, and TFIIIB70; may be involved in the recruitment of pol III by the preinitiation complex ORF Verified inviable YJL014W S000003551 CCT3 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YJL015C S000003552 Hypothetical protein; open reading frame is located in promoter region of essential CCT3 gene encoding a subunit of the cytosolic chaperonin Cct ring complex and also overlaps uncharacterized ORF YJL016W ORF Dubious inviable YJL019W S000003556 MPS3 Essential integral membrane protein required for spindle pole body duplication and for nuclear fusion, localizes to the spindle pole body half bridge, interacts with DnaJ-like chaperone Jem1p and with centrin homolog Cdc31p ORF Verified inviable YJL025W S000003562 RRN7 Protein involved in the transcription of 35S rRNA genes by RNA polymerase I; component of the core factor (CF) complex also composed of Rrn11p, Rrn6p and TATA-binding protein ORF Verified inviable YJL026W S000003563 RNR2 Ribonucleotide-diphosphate reductase (RNR), small subunit; the RNR complex catalyzes the rate-limiting step in dNTP synthesis and is regulated by DNA replication and DNA damage checkpoint pathways via localization of the small subunits ORF Verified inviable YJL031C S000003568 BET4 Alpha subunit of Type II geranylgeranyltransferase required for vesicular transport between the endoplasmic reticulum and the Golgi; provides a membrane attachment moiety to Rab-like proteins Ypt1p and Sec4p ORF Verified inviable YJL032W S000003569 Hypothetical protein; open reading frame overlaps 3' end of essential BET4 gene encoding the alpha subunit of Type II geranylgeranyltransferase ORF Dubious inviable YJL033W S000003570 HCA4 Putative nucleolar DEAD box RNA helicase; high-copy number suppression of a U14 snoRNA processing mutant suggests an involvement in 18S rRNA synthesis ORF Verified inviable YJL034W S000003571 KAR2 ATPase involved in protein import into the ER, also acts as a chaperone to mediate protein folding in the ER and may play a role in ER export of soluble proteins; regulates the unfolded protein response via interaction with Ire1p ORF Verified inviable YJL035C S000003572 TAD2 Subunit of tRNA-specific adenosine-34 deaminase, forms a heterodimer with Tad3p that converts adenosine to inosine at the wobble position of several tRNAs ORF Verified inviable YJL039C S000003576 NUP192 Essential structural subunit of the nuclear pore complex (NPC), localizes to the nuclear periphery of nuclear pores, homologous to human p205 ORF Verified inviable YJL041W S000003577 NSP1 Essential component of the nuclear pore complex, which mediates nuclear import and export ORF Verified inviable YJL050W S000003586 MTR4 Dead-box family ATP dependent helicase required for mRNA export from the nucleus; co-factor of the exosome complex, required for 3' end formation of 5.8S rRNA ORF Verified inviable YJL054W S000003590 TIM54 Component of the mitochondrial Tim54p-Tim22p complex involved in insertion of polytopic proteins into the inner membrane ORF Verified inviable YJL061W S000003597 NUP82 Subunit of the nuclear pore complex (NPC), forms a subcomplex with Nup159p and Nsp1p, interacts with Nup116p and is required for proper localization of Nup116p in the NPC ORF Verified inviable YJL069C S000003605 UTP18 Possible U3 snoRNP protein involved in maturation of pre-18S rRNA, based on computational analysis of large-scale protein-protein interaction data ORF Uncharacterized inviable YJL072C S000003608 PSF2 Subunit of the GINS complex (Sld5p, Psf1p, Psf2p, Psf3p), which is localized to DNA replication origins and implicated in assembly of the DNA replication machinery ORF Verified inviable YJL074C S000003610 SMC3 Subunit of the multiprotein cohesin complex required for sister chromatid cohesion in mitotic cells; also required, with Rec8p, for cohesion and recombination during meiosis; phylogenetically conserved SMC chromosomal ATPase family member ORF Verified inviable YJL076W S000003612 NET1 Core subunit of the RENT complex, which is a complex involved in nucleolar silencing and telophase exit; stimulates transcription by RNA polymerase I and regulates nucleolar structure ORF Verified inviable YJL081C S000003617 ARP4 Nuclear actin-related protein involved in chromatin remodeling, component of chromatin-remodeling enzyme complexes ORF Verified inviable YJL085W S000003621 EXO70 Essential 70kDa subunit of the exocyst complex (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p, and Exo84p), which has the essential function of mediating polarized targeting of secretory vesicles to active sites of exocytosis ORF Verified inviable YJL086C S000003622 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; partially overlaps the verified genes YJL085W/EXO70 and YJL087C/TRL1 ORF Dubious inviable YJL087C S000003623 TRL1 tRNA ligase, required for tRNA splicing; composed of three essential domains containing the phosphodiesterase, polynucleotide kinase, and ligase activities required for ligation; localized at the inner membrane of the nuclear envelope ORF Verified inviable YJL090C S000003626 DPB11 Essential BRCT repeat protein, required on the prereplicative complex at replication origins for loading DNA polymerases to initiate DNA synthesis, also required for S/M checkpoint control ORF Verified inviable YJL091C S000003627 GWT1 Protein involved in the inositol acylation of glucosaminyl phosphatidylinositol (GlcN-PI) to form glucosaminyl(acyl)phosphatidylinositol (GlcN(acyl)PI), an intermediate in the biosynthesis of glycosylphosphatidylinositol (GPI) anchors ORF Verified inviable YJL097W S000003633 PHS1 Protein of unknown function; homolog of mammalian PTPLA; involved in sphingolipid biosynthesis; required for cell viability ORF Uncharacterized inviable YJL104W S000003640 PAM16 Constituent of the mitochondrial import motor associated with the presequence translocase, along with Ssc1p, Tim44p, Mge1p, and Pam18p; has similarity to J-domain containing proteins ORF Verified inviable YJL109C S000003645 UTP10 Nucleolar protein, component of the small subunit (SSU) processome containing the U3 snoRNA that is involved in processing of pre-18S rRNA ORF Verified inviable YJL111W S000003647 CCT7 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YJL125C S000003661 GCD14 Subunit of tRNA (1-methyladenosine) methyltransferase, with Gcd10p, required for the modification of the adenine at position 58 in tRNAs, especially tRNAi-Met; first identified as a negative regulator of GCN4 expression ORF Verified inviable YJL143W S000003679 TIM17 Essential constituent of the mitochondrial inner membrane presequence translocase; interacts with Pam18p to recruit the presequence translocase-associated motor (PAM complex) and also required for protein sorting during import ORF Verified inviable YJL156C S000003692 SSY5 Probable serine protease of the SPS plasma membrane amino acid sensor system (Ssy1p-Ptr3p-Ssy5p), which senses external amino acid concentration and transmits intracellular signals that regulate expression of amino acid permease genes ORF Verified inviable YJL167W S000003703 ERG20 Farnesyl pyrophosphate synthetase, has both dimethylallyltranstransferase and geranyltranstransferase activities; catalyzes the formation of C15 farnesyl pyrophosphate units for isoprenoid and sterol biosynthesis ORF Verified inviable YJL173C S000003709 RFA3 Subunit of heterotrimeric Replication Factor A (RF-A), which is a highly conserved single-stranded DNA binding protein involved in DNA replication, repair, and recombination ORF Verified inviable YJL174W S000003710 KRE9 Glycoprotein involved in cell wall beta-glucan assembly; null mutation leads to severe growth defects, aberrant multibudded morphology, and mating defects ORF Verified inviable YJL194W S000003730 CDC6 Essential ATP-binding protein required for DNA replication, component of the pre-replicative complex (pre-RC) which requires ORC to associate with chromatin and is in turn required for Mcm2-7p DNA association; homologous to S. pombe Cdc18p ORF Verified inviable YJL195C S000003731 Dubious open reading frame unlikely to encode a protein, based on available experimental and comparative sequence data; partially overlaps the verified gene YJL194W/CDC6 ORF Dubious inviable YJL202C S000003738 Hypothetical protein; open reading frame overlaps 3' end of essential PRP21 gene encoding a subunit of the SF3a splicing factor complex ORF Dubious inviable YJL203W S000003739 PRP21 Subunit of the SF3a splicing factor complex, required for spliceosome assembly ORF Verified inviable YJR002W S000003762 MPP10 Component of the SSU processome, which is required for pre-18S rRNA processing, interacts with and controls the stability of Imp3p and Imp4p, essential for viability; similar to human Mpp10p ORF Verified inviable YJR006W S000003766 HYS2 DNA polymerase III (delta) subunit, essential for cell viability; involved in DNA replication and DNA repair ORF Verified inviable YJR007W S000003767 SUI2 Alpha subunit of the translation initiation factor eIF2, involved in the identification of the start codon; phosphorylation of Ser51 is required for regulation of translation by inhibiting the exchange of GDP for GTP ORF Verified inviable YJR012C S000003773 Putative protein of unknown function; proposed involvement in transport based on mass spectrometry analysis of copurifying proteins; partially overlaps neighboring ORF, GPI14/YJR013W ORF Uncharacterized inviable YJR013W S000003774 GPI14 Glycosylphosphatidylinositol-alpha 1,4 mannosyltransferase I, involved in GPI anchor biosynthesis, requires Pbn1p for function; homolog of mammalian PIG-M ORF Uncharacterized inviable YJR016C S000003777 ILV3 Dihydroxyacid dehydratase, catalyzes third step in the common pathway leading to biosynthesis of branched-chain amino acids ORF Verified inviable YJR017C S000003778 ESS1 Peptidylprolyl-cis/trans-isomerase (PPIase) specific for phosphorylated serine and threonine residues N-terminal to proline; regulates phosphorylation of the RNA polymerase II large subunit (Rpo21p) C-terminal domain ORF Verified inviable YJR022W S000003783 LSM8 Lsm (Like Sm) protein; forms heteroheptameric complex (with Lsm2p, Lsm3p, Lsm4p, Lsm5p, Lsm6p, and Lsm7p) that is part of spliceosomal U6 snRNP and is also implicated in processing of pre-tRNA, pre-snoRNA, and pre-rRNA ORF Verified inviable YJR023C S000003784 Hypothetical protein; open reading frame overlaps essential LSM8 gene encoding an snRNP protein required for RNA processing and splicing ORF Dubious inviable YJR041C S000003802 URB2 Nucleolar protein required for normal metabolism of the rRNA primary transcript, proposed to be involved in ribosome biogenesis ORF Verified inviable YJR042W S000003803 NUP85 Subunit of the Nup84p subcomplex of the nuclear pore complex (NPC), required for assembly of the subcomplex and also for formation of the nucleocytoplasmic Gsp1p concentration gradient that plays a role in nuclear trafficking ORF Verified inviable YJR045C S000003806 SSC1 Mitochondrial matrix ATPase that is a subunit of the presequence translocase-associated protein import motor (PAM); involved in protein translocation into the matrix and protein folding; member of the heat shock protein 70 (HSP70) family ORF Verified inviable YJR046W S000003807 TAH11 DNA replication licensing factor, required for pre-replication complex assembly ORF Verified inviable YJR057W S000003818 CDC8 Thymidylate and uridylate kinase, functions in de novo biosynthesis of pyrimidine deoxyribonucleotides; converts dTMP to dTDP and dUMP to dUTP; essential for mitotic and meiotic DNA replication; homologous to S. pombe Tmp1p ORF Verified inviable YJR064W S000003825 CCT5 Subunit of the cytosolic chaperonin Cct ring complex, related to Tcp1p, required for the assembly of actin and tubulins in vivo ORF Verified inviable YJR065C S000003826 ARP3 Essential component of the Arp2/3 complex, which is a highly conserved actin nucleation center required for the motility and integrity of actin patches; involved in endocytosis and membrane growth and polarity ORF Verified inviable YJR067C S000003828 YAE1 Essential protein of unknown function ORF Verified inviable YJR068W S000003829 RFC2 Subunit of heteropentameric Replication factor C (RF-C), which is a DNA binding protein and ATPase that acts as a clamp loader of the proliferating cell nuclear antigen (PCNA) processivity factor for DNA polymerases delta and epsilon ORF Verified inviable YJR072C S000003833 NPA3 Essential, conserved, cytoplasmic ATPase; phosphorylated by the Pcl1p-Pho85p kinase complex ORF Verified inviable YJR076C S000003837 CDC11 Component of the septin ring of the mother-bud neck that is required for cytokinesis; septins recruit proteins to the neck and can act as a barrier to diffusion at the membrane, and they comprise the 10nm filaments seen with EM ORF Verified inviable YJR093C S000003853 FIP1 Subunit of cleavage polyadenylation factor (CPF), interacts directly with poly(A) polymerase (Pap1p) to regulate its activity ORF Verified inviable YJR112W S000003873 NNF1 Essential component of the MIND kinetochore complex (Mtw1p Including Nnf1p-Nsl1p-Dsn1p) which joins kinetochore subunits contacting DNA to those contacting microtubules; required for accurate chromosome segregation ORF Verified inviable YJR123W S000003884 RPS5 Protein component of the small (40S) ribosomal subunit, the least basic of the non-acidic ribosomal proteins; phosphorylated in vivo; essential for viability; has similarity to E. coli S7 and rat S5 ribosomal proteins ORF Verified inviable YJR141W S000003902 Putative protein of unknown function; may be involved in mRNA processing; YJR141W is an essential gene ORF Uncharacterized inviable YKL004W S000001487 AUR1 Phosphatidylinositol:ceramide phosphoinositol transferase (IPC synthase), required for sphingolipid synthesis; can mutate to confer aureobasidin A resistance ORF Verified inviable YKL006C-A S000002101 SFT1 Intra-Golgi v-SNARE, required for transport of proteins between an early and a later Golgi compartment ORF Verified inviable YKL012W S000001495 PRP40 U1 snRNP protein involved in splicing, interacts with the branchpoint-binding protein during the formation of the second commitment complex ORF Verified inviable YKL013C S000001496 ARC19 Subunit of the ARP2/3 complex, which is required for the motility and integrity of cortical actin patches ORF Verified inviable YKL014C S000001497 URB1 Nucleolar protein required for the normal accumulation of 25S and 5.8S rRNAs, associated with the 27SA2 pre-ribosomal particle; proposed to be involved in the biogenesis of the 60S ribosomal subunit ORF Verified inviable YKL018W S000001501 SWD2 Subunit of the COMPASS (Set1C) complex, which methylates histone H3 on lys 4 and is involved in telomeric silencing; subunit of CPF (cleavage and polyadenylation factor), a complex involved in RNAP II transcription termination ORF Verified inviable YKL019W S000001502 RAM2 Alpha subunit of both the farnesyltransfer