A Canonical Biotin Synthesis Enzyme, 8-Amino-7-Oxononanoate Synthase (BioF), Utilizes Different Acyl Chain Donors in Bacillus subtilis and Escherichia coli.

BioF (8-amino-7-oxononanoate synthase) is a strictly conserved enzyme that catalyzes the first step in assembly of the fused heterocyclic rings of biotin. The BioF acyl chain donor has long been thought to be pimeloyl-CoA. Indeed, the and enzymes have been shown to condense pimeloyl-CoA with l-alanine in a pyridoxal 5'-phosphate-dependent reaction with concomitant CoA release and decarboxylation of l-alanine. However, recent studies of and suggested that the BioF proteins of the two bacteria could have different specificities for pimelate thioesters in that BioF may utilize either pimeloyl coenzyme A (CoA) or the pimelate thioester of the acyl carrier protein (ACP) of fatty acid synthesis. In contrast, BioF seemed likely to be specific for pimeloyl-CoA and unable to utilize pimeloyl-ACP. We now report genetic and data demonstrating that BioF specifically utilizes pimeloyl-CoA. Biotin is an essential vitamin required by mammals and birds because, unlike bacteria, plants, and some fungi, these organisms cannot make biotin. Currently, the biotin included in vitamin tablets and animal feeds is made by chemical synthesis. This is partly because the biosynthetic pathways in bacteria are incompletely understood. This paper defines an enzyme of the pathway and shows that it differs from that of in the ability to utilize specific precursors. These bacteria have been used in biotin production and these data may aid in making biotin produced by biotechnology commercially competitive with that produced by chemical synthesis.