Reaction: (8S)-8-amino-7-oxononanoate + [protein]-L-lysine + CO2 = (7R,8S)-8-amino-7-(carboxyamino)nonanoate + [protein]-(S)-2-amino-6-oxohexanoate (overall reaction)
(1a) (8S)-8-amino-7-oxononanoate + [protein]-L-lysine + NAD(P)H = [protein]-N6-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysine + H2O + NAD(P)+
(1b) [protein]-N6-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysine + CO2 + H2O + NAD(P)+ + H+ = (7R,8S)-8-amino-7-(carboxyamino)nonanoate + [protein]-(S)-2-amino-6-oxohexanoate + NAD(P)H + H+
Other name(s): bioU (gene name)
Systematic name: (8S)-8-amino-7-oxononanoate:[protein]-L-lysine aminotransferase (N-carboxylating)
Comments: The enzyme, which participates in biotin biosynthesis, is found in haloarchaea and some cyanobacteria. It forms a conjugant between (7R,8S)-8-amino-7-oxononanoate and an internal lysine residue and catalyses multiple reactions, including a reduction, a carboxylation of the ε-amino group of the lysine residue, and an oxidative cleavage of the conjugate to release (7R,8S)-8-amino-7-(carboxyamino)nonanoate. During this process the lysine residue serves as an amino donor and is converted to (S)-2-amino-6-oxohexanoate, resulting in inactivation of the enzyme following a single turnover. cf. EC 188.8.131.52, lysine—8-amino-7-oxononanoate transaminase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Sakaki, K., Ohishi, K., Shimizu, T., Kobayashi, I., Mori, N., Matsuda, K., Tomita, T., Watanabe, H., Tanaka, K., Kuzuyama, T. and Nishiyama, M. A suicide enzyme catalyzes multiple reactions for biotin biosynthesis in cyanobacteria. Nat. Chem. Biol. 16 (2020) 415-422. [PMID: 32042199]