Bna3 (YJL060W) is a class-I pyridoxal 5'-phosphate-dependent aminotransferase of Saccharomyces cerevisiae that acts as the yeast kynurenine aminotransferase (KAT; EC 2.6.1.7), transaminating L-kynurenine with 2-oxoglutarate to form kynurenic acid. This side branch diverts kynurenine away from the quinolinate/NAD+ route. Although originally named for a presumed role in nicotinic acid biosynthesis as the N-formylkynurenine formamidase, crystallographic and biochemical work showed that the formamidase is Bna7 and that Bna3 is the KAT. Bna3 is a homodimer and is dual-localized to the cytosol and mitochondria. It has also been reported to have 2-aminoadipate transaminase activity.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0001558 regulation of cell growth | IMP NOT PMID:18205391 Identification of formyl kynurenine formamidase and kynureni... | ACCEPT | Summary: NOT annotation (IMP) from Wogulis et al. 2008: deletion of BNA3 did not affect growth. Deferring to the curator, who read the full text; the negative statement does not conflict with the enzyme assignment. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO 'catalytic activity' from IPR004838. Uninformative root-level MF; the specific activity is kynurenine:2-oxoglutarate transaminase. Reason: Generic parent of a known specific activity. Proposed replacements: L-kynurenine:2-oxoglutarate transaminase activity Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0004061 arylformamidase activity | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:NADSYN-PWY assigns Bna3 to the N-formylkynurenine formamidase step (EC 3.5.1.9). This is the historical mis-assignment refuted by Wogulis et al. 2008: Bna3 is not a formamidase, and the yeast formamidase is Bna7/YDR428C, an alpha/beta hydrolase. Reason: Arylformamidase activity was shown to belong to BNA7, not BNA3; the pathway database retains an obsolete gene-reaction assignment. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0004061 arylformamidase activity | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:PWY-5651 assigns Bna3 to the N-formylkynurenine formamidase step (EC 3.5.1.9). This is the historical mis-assignment refuted by Wogulis et al. 2008: Bna3 is not a formamidase, and the yeast formamidase is Bna7/YDR428C, an alpha/beta hydrolase. Reason: Arylformamidase activity was shown to belong to BNA7, not BNA3; the pathway database retains an obsolete gene-reaction assignment. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0004061 arylformamidase activity | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:PWY3O-4158 assigns Bna3 to the N-formylkynurenine formamidase step (EC 3.5.1.9). This is the historical mis-assignment refuted by Wogulis et al. 2008: Bna3 is not a formamidase, and the yeast formamidase is Bna7/YDR428C, an alpha/beta hydrolase. Reason: Arylformamidase activity was shown to belong to BNA7, not BNA3; the pathway database retains an obsolete gene-reaction assignment. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0004061 arylformamidase activity | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:TRYPTOPHAN-DEGRADATION-1 assigns Bna3 to the N-formylkynurenine formamidase step (EC 3.5.1.9). This is the historical mis-assignment refuted by Wogulis et al. 2008: Bna3 is not a formamidase, and the yeast formamidase is Bna7/YDR428C, an alpha/beta hydrolase. Reason: Arylformamidase activity was shown to belong to BNA7, not BNA3; the pathway database retains an obsolete gene-reaction assignment. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0005737 cytoplasm | HDA PMID:14562095 Global analysis of protein localization in budding yeast. | ACCEPT | Summary: HDA from the Huh et al. 2003 GFP survey (cytoplasm and mitochondrion). Supporting Evidence: PMID:14562095 Global analysis of protein localization in budding yeast. |
| GO:0005737 cytoplasm | IDA PMID:17034789 Alpha-complementation as a probe for dual localization of mi... | ACCEPT | Summary: IDA from Karniely et al. 2006: cytosolic pool detected by alpha-complementation. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt SubCell mapping (SL-0086) of the cytoplasmic GFP signal. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005739 mitochondrion | HDA PMID:14562095 Global analysis of protein localization in budding yeast. | ACCEPT | Summary: HDA from a mitochondrial proteome / localization survey (PMID:14562095). Consistent with the dual cytosol/mitochondria distribution. Supporting Evidence: PMID:14562095 Global analysis of protein localization in budding yeast. |
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | ACCEPT | Summary: HDA from a mitochondrial proteome / localization survey (PMID:16823961). Consistent with the dual cytosol/mitochondria distribution. Supporting Evidence: PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimensional separation techniques for mitochondrial proteomics. |
| GO:0005739 mitochondrion | HDA PMID:24769239 Quantitative variations of the mitochondrial proteome and ph... | ACCEPT | Summary: HDA from a mitochondrial proteome / localization survey (PMID:24769239). Consistent with the dual cytosol/mitochondria distribution. Supporting Evidence: PMID:24769239 Quantitative variations of the mitochondrial proteome and phosphoproteome during fermentative and respiratory growth in Saccharomyces cerevisiae. |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000203187 seeded by rat KAT (RGD:1306912) and Bna3 itself. Bna3 has a mitochondrial pool, shown by alpha-complementation and mitochondrial proteomics. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005739 mitochondrion | IDA PMID:17034789 Alpha-complementation as a probe for dual localization of mi... | ACCEPT | Summary: IDA from Karniely et al. 2006: alpha-complementation shows Bna3 is dual-distributed between cytosol and mitochondria. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005739 mitochondrion | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt SubCell mapping (SL-0173) of the experimentally observed mitochondrial location. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways SGD_PWY:NADSYN-PWY default compartment. Independently correct: Bna3 has a cytosolic pool. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways SGD_PWY:PWY-5651 default compartment. Independently correct: Bna3 has a cytosolic pool. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways SGD_PWY:PWY3O-4158 default compartment. Independently correct: Bna3 has a cytosolic pool. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways SGD_PWY:TRYPTOPHAN-DEGRADATION-1 default compartment. Independently correct: Bna3 has a cytosolic pool. Supporting Evidence: PMID:17034789 Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria. |
| GO:0006569 L-tryptophan catabolic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: YeastPathways SGD_PWY:PWY-5651 (L-tryptophan degradation), attached via the incorrect formamidase assignment. Bna3 does act on a tryptophan catabolite (kynurenine -> kynurenic acid, a side branch), so the broad process is defensible, but not via the step YeastPathways assigns. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0006569 L-tryptophan catabolic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: YeastPathways SGD_PWY:TRYPTOPHAN-DEGRADATION-1 (L-tryptophan degradation), attached via the incorrect formamidase assignment. Bna3 does act on a tryptophan catabolite (kynurenine -> kynurenic acid, a side branch), so the broad process is defensible, but not via the step YeastPathways assigns. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0009435 NAD+ biosynthetic process | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:NADSYN-PWY NAD+ biosynthesis, derived from the obsolete assignment of Bna3 to the formamidase step. As a KAT, Bna3 diverts kynurenine to kynurenic acid, away from quinolinate and NAD+. Reason: Pathway membership follows from a refuted reaction assignment; KAT activity is not a step of NAD+ synthesis. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0009435 NAD+ biosynthetic process | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways SGD_PWY:PWY3O-4158 NAD+ biosynthesis, derived from the obsolete assignment of Bna3 to the formamidase step. As a KAT, Bna3 diverts kynurenine to kynurenic acid, away from quinolinate and NAD+. Reason: Pathway membership follows from a refuted reaction assignment; KAT activity is not a step of NAD+ synthesis. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. PMID:18205391 demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF. |
| GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000203188 seeded by human KYAT1 (Q16773), mouse and rat KATs, and Bna3 itself. Consistent with Wogulis et al. identifying Bna3 as the yeast KAT. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. file:yeast/BNA3/BNA3-uniprot.txt Reaction=L-kynurenine + 2-oxoglutarate = kynurenate + L-glutamate + |
| GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity | IDA PMID:18205391 Identification of formyl kynurenine formamidase and kynureni... | ACCEPT | Summary: IDA from Wogulis et al. 2008 (abstract only cached): biochemical evidence that Bna3 is the yeast kynurenine aminotransferase. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA from RHEA:65560 and EC 2.6.1.7 on the UniProt entry. Correct. Supporting Evidence: file:yeast/BNA3/BNA3-uniprot.txt Reaction=L-kynurenine + 2-oxoglutarate = kynurenate + L-glutamate + |
| GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity | ISS PMID:18205391 Identification of formyl kynurenine formamidase and kynureni... | ACCEPT | Summary: ISS to human KYAT1 (Q16773) from Wogulis et al. 2008, which used structure and sequence comparison to reassign Bna3 as KAT. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0030170 pyridoxal phosphate binding | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO (IPR004838/IPR004839, class-I aminotransferase). PLP is the cofactor of Bna3. Supporting Evidence: file:yeast/BNA3/BNA3-uniprot.txt Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; |
| GO:0034276 kynurenic acid biosynthetic process | IDA PMID:18205391 Identification of formyl kynurenine formamidase and kynureni... | ACCEPT | Summary: IDA from Wogulis et al. 2008: Bna3 converts kynurenine to kynurenic acid. This is the process directly served by KAT activity. Supporting Evidence: PMID:18205391 demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. |
| GO:0047536 L-2-aminoadipate:2-oxoglutarate transaminase activity | IDA PMID:19342587 The automation of science. | KEEP AS NON CORE | Summary: IDA from King et al. 2009 (Robot Scientist 'Adam'), which tested hypotheses about the genes encoding the orphan 2-aminoadipate:2-oxoglutarate aminotransferase activity. The abstract does not name genes; deferring to the curator. A side-activity of a broad-specificity class-I aminotransferase is plausible (mammalian KAT II/AADAT has both), but the physiological lysine-pathway aminotransferase role belongs to other enzymes. Supporting Evidence: PMID:19342587 Adam has autonomously generated functional genomics hypotheses about the yeast Saccharomyces cerevisiae and experimentally tested these hypotheses by using laboratory automation. |
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Download this section (compressed HTML)Q: What is the physiological substrate preference of Bna3 (kynurenine vs 2-aminoadipate vs aromatic amino acids) and does its mitochondrial pool have a distinct role?
Experiment: Steady-state kinetics of purified Bna3 with kynurenine, 2-aminoadipate and aromatic amino acids, and metabolite profiling (kynurenic acid) of bna3 deletion strains.
Kynurenine aminotransferase; catalyzes formation of kynurenic acid from kynurenine; potential Cdc28p substrate
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