YJL045W (SDH1b) encodes a minor paralog of the succinate dehydrogenase flavoprotein subunit Sdh1p (SDHA family, FAD-dependent oxidoreductase 2 family). On a plasmid it restores respiration and SDH activity in sdh1 mutants. Residual SDH activity in sdh1 single disruptants depends on it, so it can act as the catalytic flavoprotein of complex II (succinate:quinone oxidoreductase, EC 1.3.5.1), oxidizing succinate to fumarate at its FAD and passing electrons to Sdh2p. Its promoter activity is 100-500-fold lower than SDH1's, and its deletion alone has no obvious phenotype, so it contributes little to respiration under standard conditions. It localizes to mitochondria.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005739 mitochondrion | HDA PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. | ACCEPT | Summary: High-throughput localization of YJL045Wp to mitochondria in the Sickmann et al. 2003 MS proteome of highly purified mitochondria. Correct but less specific than the experimentally supported sub-mitochondrial location. Detection of this low-abundance paralog in purified mitochondria supports mitochondrial targeting. Supporting Evidence: PMID:14576278 The proteins of highly pure yeast mitochondria were separated by several independent methods and analyzed by tandem MS. |
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | ACCEPT | Summary: High-throughput localization of YJL045Wp to mitochondria in the PROMITO multidimensional MS survey of purified yeast mitochondria (Reinders et al. 2006). Correct but less specific than the experimentally supported sub-mitochondrial location. Supporting Evidence: PMID:16823961 A total of 851 different proteins (PROMITO dataset) were identified by use of multidimensional LC-MS/MS |
| GO:0005739 mitochondrion | HDA PMID:24769239 Quantitative variations of the mitochondrial proteome and ph... | ACCEPT | Summary: High-throughput localization of YJL045Wp to mitochondria in the carbon-source quantitative mitochondrial proteome/phosphoproteome study (Renvoise et al. 2014). Correct but less specific than the experimentally supported sub-mitochondrial location. Supporting Evidence: PMID:24769239 we performed an overall quantitative proteomic and phosphoproteomic study of isolated mitochondria extracted from yeast grown on fermentative (glucose or galactose) and respiratory (lactate) media |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN000180258, SDHA flavoprotein clade) is_active_in mitochondrion. Correct for this Sdh1p paralog. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Mitochondrion inner membrane |
| GO:0005743 mitochondrial inner membrane | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt SL-0168 mapping to mitochondrial inner membrane. UniProt bases this on similarity to Sdh1p (matrix-side peripheral membrane protein). Reasonable. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Mitochondrion inner membrane |
| GO:0005743 mitochondrial inner membrane | ISS GO_REF:0000024 | ACCEPT | Summary: ISS from Sdh1p (Q00711) to inner membrane. Reasonable: YJL045W can substitute for Sdh1p in complex II when overexpressed. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0005743 mitochondrial inner membrane | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA from TCA-EUK-PWY, is_active_in inner membrane. Acceptable for the minor flavoprotein isoform. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Mitochondrion inner membrane |
| GO:0006099 tricarboxylic acid cycle | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (InterPro IPR011281 SDH flavoprotein; UniPathway) to TCA cycle. YJL045W is an active SDH flavoprotein but is expressed 100-500-fold below SDH1 and its deletion has no phenotype. The TCA role is real but minor. Supporting Evidence: PMID:9730279 indicates that the isoenzyme encoded by SDH1b is unlikely to play an important role in mitochondrial respiration PMID:16232921 the activity disappeared in double disruptants of the SDH1 and SDH2 or SDH1b (the SDH1 homologue) genes |
| GO:0006121 mitochondrial electron transport, succinate to ubiquinone | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN000180258) to succinate-to-ubiquinone electron transport. Correct for an SDHA-family flavoprotein able to restore respiration in sdh1 mutants. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0008177 succinate dehydrogenase (quinone) activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (ARBA, IPR011281, RHEA:40523, EC 1.3.5.1) to SQR activity. Correct. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; |
| GO:0008177 succinate dehydrogenase (quinone) activity | IGI PMID:16232921 Effect of gene disruption of succinate dehydrogenase on succ... | ACCEPT | Summary: IGI with SDH1 (Kubo et al. 2000): SDH activity disappeared only in the sdh1 sdh1b double disruptant, so the SDH1b product (YJL045W) supplies residual SQR activity in sdh1 cells. Supporting Evidence: PMID:16232921 the activity disappeared in double disruptants of the SDH1 and SDH2 or SDH1b (the SDH1 homologue) genes |
| GO:0008177 succinate dehydrogenase (quinone) activity | IGI PMID:9730279 Suppression of sdh1 mutations by the SDH1b gene of Saccharom... | ACCEPT | Summary: IGI with SDH1 (Colby et al. 1998): YJL045W (SDH1b) on a plasmid restored respiration in an sdh1 mutant that lacked SDH activity, so it is a functional SDH flavoprotein. Supporting Evidence: PMID:9730279 The second plasmid (pG52/T8) had an insert with reading frame (YJL045w) of yeast chromosome X coding for a homologue of SDH1. PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0008177 succinate dehydrogenase (quinone) activity | IMP PMID:16232921 Effect of gene disruption of succinate dehydrogenase on succ... | ACCEPT | Summary: IMP (Kubo et al. 2000): SDH1b disruption, combined with sdh1, removes the remaining SDH activity. Supporting Evidence: PMID:16232921 the activity disappeared in double disruptants of the SDH1 and SDH2 or SDH1b (the SDH1 homologue) genes |
| GO:0008177 succinate dehydrogenase (quinone) activity | ISS GO_REF:0000024 | ACCEPT | Summary: ISS from bovine/human SDHA (P31040) to SQR activity. Correct by orthology and supported by yeast complementation. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0008177 succinate dehydrogenase (quinone) activity | ISS PMID:9730279 Suppression of sdh1 mutations by the SDH1b gene of Saccharom... | ACCEPT | Summary: ISS (Colby et al. 1998) from Sdh1p: YJL045W is an SDH1 homologue. Correct. Supporting Evidence: PMID:9730279 The second plasmid (pG52/T8) had an insert with reading frame (YJL045w) of yeast chromosome X coding for a homologue of SDH1. |
| GO:0008177 succinate dehydrogenase (quinone) activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA contributes_to SQR. Correct, as the flavoprotein acts within complex II. Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; |
| GO:0009060 aerobic respiration | RCA GO_REF:0000123 | TOO GENERAL | Summary: YeastPathways RCA to aerobic respiration. Correct, broad; the physiological contribution is minor. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0016491 oxidoreductase activity | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO to generic oxidoreductase activity. Uninformative. Reason: Replace with the specific SQR activity. Proposed replacements: succinate dehydrogenase (quinone) activity Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; |
| GO:0016627 oxidoreductase activity, acting on the CH-CH group of donors | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO (IPR014006) to 'oxidoreductase activity, acting on the CH-CH group of donors'. Correct parent of the specific activity (succinate oxidation is CH-CH to quinone). Reason: Use the specific SQR term. Proposed replacements: succinate dehydrogenase (quinone) activity Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; |
| GO:0022900 electron transport chain | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO (IPR014006) to 'electron transport chain'. Correct but broad. The specific process is GO:0006121, already annotated by IBA. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0032991 protein-containing complex | RCA GO_REF:0000123 | MODIFY | Summary: YeastPathways RCA part_of generic 'protein-containing complex'. Uninformative. Reason: Use the specific complex term. Proposed replacements: respiratory chain complex II (succinate dehydrogenase) Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Reaction=a quinone + succinate = fumarate + a quinol; |
| GO:0045273 respiratory chain complex II (succinate dehydrogenase) | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN000180258) part_of complex II. Reasonable. It can stand in for Sdh1p in complex II, though direct biochemical isolation of a YJL045W-containing complex has not been shown. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0045333 cellular respiration | IEA GO_REF:0000117 | TOO GENERAL | Summary: ARBA IEA to cellular respiration. Correct, broad. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0045333 cellular respiration | IGI PMID:16232921 Effect of gene disruption of succinate dehydrogenase on succ... | TOO GENERAL | Summary: IGI with SDH1 (Kubo et al. 2000): sdh1 sdh1b double disruptant cannot grow on glycerol. Supporting Evidence: PMID:16232921 Two double disruptants showed no growth on a medium containing glycerol as the sole carbon source, while the single disruptants could utilize glycerol. PMID:16232921 the activity disappeared in double disruptants of the SDH1 and SDH2 or SDH1b (the SDH1 homologue) genes |
| GO:0045333 cellular respiration | IGI PMID:9730279 Suppression of sdh1 mutations by the SDH1b gene of Saccharom... | TOO GENERAL | Summary: IGI with SDH1 (Colby et al. 1998): SDH1b restores respiration in an sdh1 mutant. Supporting Evidence: PMID:9730279 Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. |
| GO:0045333 cellular respiration | IMP PMID:16232921 Effect of gene disruption of succinate dehydrogenase on succ... | TOO GENERAL | Summary: IMP (Kubo et al. 2000) to cellular respiration. Correct (double-mutant context). Supporting Evidence: PMID:16232921 Two double disruptants showed no growth on a medium containing glycerol as the sole carbon source, while the single disruptants could utilize glycerol. |
| GO:0050660 flavin adenine dinucleotide binding | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO to FAD binding. Correct: SDHA-family flavoproteins carry covalently bound FAD (UniProt, by similarity). Supporting Evidence: file:yeast/YJL045W/YJL045W-uniprot.txt Name=FAD; Xref=ChEBI:CHEBI:57692; |
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Download this section (compressed HTML)Minor succinate dehydrogenase isozyme; participates in oxidation of succinate and transfer of electrons to ubiquinone; induced during the diauxic shift in a Cat8p-dependent manner; YJL045W has a paralog, SDH1, that arose from the whole genome duplication
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