Bio3p is the 7,8-diaminopelargonic acid (DAPA) aminotransferase (BioA; EC 2.6.1.62) of Saccharomyces cerevisiae, a class-III pyridoxal 5'-phosphate-dependent aminotransferase that transfers the alpha-amino group of S-adenosyl-L-methionine to 8-amino-7-oxononanoate (KAPA), forming DAPA in the biotin biosynthesis pathway. It is unusual among aminotransferases in using SAM as the amino donor. BIO3 lies in a subtelomeric cluster with BIO4 (dethiobiotin synthetase) and BIO5 (a transporter for KAPA), and enables yeast to make biotin from exogenous KAPA or DAPA precursors. Unlike the plant BIO1 enzyme, Bio3p is a monofunctional aminotransferase with no dethiobiotin synthetase domain.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004015 S-adenosyl-L-methionine:8-amino-7-oxononanoate transaminase activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000241343, seeded by E. coli BioA (P12995), M. tuberculosis BioA, Arabidopsis BIO1 and Bio3 itself. Bio3 is a canonical BioA-subfamily class-III aminotransferase, so inheritance is sound. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0004015 S-adenosyl-L-methionine:8-amino-7-oxononanoate transaminase activity | IDA PMID:10333520 Characterization of the biotin biosynthesis pathway in Sacch... | ACCEPT | Summary: IDA from Phalip et al. 1999 (abstract cached); the study demonstrates BIO3 encodes DAPA aminotransferase. Defer to SGD curator for assay details. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0004015 S-adenosyl-L-methionine:8-amino-7-oxononanoate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA from InterPro IPR005815 (BioA) and RHEA:16861 / EC 2.6.1.62. Correct. Supporting Evidence: file:yeast/BIO3/BIO3-uniprot.txt It is the only aminotransferase known to utilize SAM as an amino donor |
| GO:0004015 S-adenosyl-L-methionine:8-amino-7-oxononanoate transaminase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways BIOTIN-SYNTHESIS-PWY places Bio3 on the SAM + KAPA -> DAPA step (EC 2.6.1.62). Correct. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0004141 dethiobiotin synthase activity | IBA GO_REF:0000033 | REMOVE | Summary: IBA from PANTHER node PTN000241344 (Eukaryota), whose only seed is Arabidopsis AT5G57590 (BIO1), a bifunctional BioD-BioA fusion. Its DTBS activity resides in the N-terminal BioD module that yeast Bio3 lacks (480 aa, single Aminotran_3 domain). In yeast, DTBS is the separate BIO4 product. The node placement transfers a fusion-partner activity to a monofunctional aminotransferase. Reason: Domain-architecture mismatch; Bio3 has no BioD domain and dethiobiotin synthase activity belongs to Bio4. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. file:yeast/BIO3/BIO3-uniprot.txt Pfam; PF00202; Aminotran_3; 1. |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | MARK AS OVER ANNOTATED | Summary: IBA from the same Arabidopsis-only seeded node PTN000241344; plant BIO1 is mitochondrial. There is no localization data for yeast Bio3, no transit peptide is annotated, and the PAINT losses table records an IRD of mitochondrion below this node, indicating PAINT does not consider it conserved across the clade. Reason: Localization propagated from a single plant fusion protein without yeast support. Supporting Evidence: file:yeast/BIO3/BIO3-uniprot.txt PATHWAY: Cofactor biosynthesis; biotin biosynthesis; 7,8- |
| GO:0005829 cytosol | RCA GO_REF:0000123 | UNDECIDED | Summary: YeastPathways default compartment. No experimental localization exists for Bio3; cytosolic location is plausible for a bacterial-type BioA without a transit peptide but unverified. Reason: Pathway default with no supporting or refuting data. Supporting Evidence: file:yeast/BIO3/BIO3-uniprot.txt PATHWAY: Cofactor biosynthesis; biotin biosynthesis; 7,8- |
| GO:0009102 biotin biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000241343 (E. coli, M. tuberculosis BioA, Arabidopsis, Aspergillus and Bio3). Correct. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0009102 biotin biosynthetic process | IDA PMID:10333520 Characterization of the biotin biosynthesis pathway in Sacch... | ACCEPT | Summary: IDA attached to the Phalip et al. 1999 enzyme demonstration. Correct process. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0009102 biotin biosynthetic process | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (InterPro IPR005815, UniPathway UPA00078). Correct. Supporting Evidence: file:yeast/BIO3/BIO3-uniprot.txt PATHWAY: Cofactor biosynthesis; biotin biosynthesis; 7,8- |
| GO:0009102 biotin biosynthetic process | IMP PMID:10333520 Characterization of the biotin biosynthesis pathway in Sacch... | ACCEPT | Summary: IMP from the engineered biotin-pathway mutant of Phalip et al. 1999. Correct. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0009102 biotin biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways BIOTIN-SYNTHESIS-PWY. Correct. Supporting Evidence: PMID:10333520 We demonstrate that BIO3 (YNR058w) and BIO4 (YNR057c) encode, respectively, a 7, 8-diaminopelargonic acid aminotransferase and a dethiobiotin synthase, involved in the biotin biosynthesis pathway. |
| GO:0030170 pyridoxal phosphate binding | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from IPR005814 (class-III aminotransferase). PLP is the required cofactor of BioA enzymes; correct cofactor binding. Supporting Evidence: file:yeast/BIO3/BIO3-uniprot.txt SIMILARITY: Belongs to the class-III pyridoxal-phosphate-dependent |
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Download this section (compressed HTML)Q: Where in the cell do Bio3 and Bio4 act, given that the final step (Bio2) is mitochondrial and dethiobiotin must reach the matrix?
Experiment: Localize tagged Bio3 and Bio4 under biotin-limiting (induced) conditions by microscopy and fractionation.
7,8-diamino-pelargonic acid aminotransferase (DAPA); catalyzes the second step in the biotin biosynthesis pathway; BIO3 is in a cluster of 3 genes (BIO3, BIO4, and BIO5) that mediate biotin synthesis; BIO3 and BIO4 were acquired by horizontal gene transfer (HGT) from bacteria
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