A 'suicide' enzyme that participates in biotin synthesis. Catalyzes the formation of (S)-8-amino-7-oxononanoate (DAN-carbamic acid) from (7R,8S)-8-amino-7-(carboxyamino)nonanoate (DAN), a function equivalent to the cannonical BioA reaction and the first half-reaction of BioD. The cellular requirement for biotin is thought be low enough that this single turnover enzyme supplies a sufficient amount of the cofactor. Overall it catalyzes three reactions: formation of a covalent linkage with 8-amino-7-oxononanoate to yield a BioU-DAN conjugate at the epsilon-amino group of Lys124 of BioU using NAD(P)H, carboxylation of the conjugate to form BioU-DAN-carbamic acid, and release of DAN-carbamic acid using NAD(P)+ (By similarity). Complements a bioA deletion in E.coli (PubMed:32042199). (8S)-8-amino-7-oxononanoate + CO2 + L-lysyl-[protein] = (7R,8S)-8-amino-7-(carboxyamino)nonanoate + (S)-2-amino-6-oxohexanoyl-[protein] + 2 H(+) (8S)-8-amino-7-oxononanoate + H(+) + L-lysyl-[protein] + NADPH = H2O + N(6)-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysyl-[protein] + NADP(+) CO2 + H2O + N(6)-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysyl-[protein] + NADP(+) = (7R,8S)-8-amino-7-(carboxyamino)nonanoate + (S)-2-amino-6-oxohexanoyl-[protein] + 3 H(+) + NADPH (8S)-8-amino-7-oxononanoate + H(+) + L-lysyl-[protein] + NADH = H2O + N(6)-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysyl-[protein] + NAD(+) CO2 + H2O + N(6)-[(2S,3R)-2-amino-8-carboxyoctan-3-yl]-L-lysyl-[protein] + NAD(+) = (7R,8S)-8-amino-7-(carboxyamino)nonanoate + (S)-2-amino-6-oxohexanoyl-[protein] + 3 H(+) + NADH Cofactor biosynthesis; biotin biosynthesis. Monomer. In cannonical biotin synthesis a pimeloyl-conjugate is transformed into biotin by the subsequent action of BioF, BioA, BioD and BioB. This enzyme replaces BioA and performs the first half-reaction of BioD. Belongs to the BioU family.