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 epsilon-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.