Lipoate-binding proteins and specific lipoate-protein ligases in microbial sulfur oxidation reveal an atpyical role for an old cofactor.

ABSTRACT: Many Bacteria and Archaea employ the heterodisulfide reductase (Hdr)-like sulfur oxidation pathway. The relevant genes are inevitably associated with genes encoding lipoate-binding proteins (LbpA). Here, deletion of the gene identified LbpA as an essential component of the Hdr-like sulfur-oxidizing system in the Alphaproteobacterium Hyphomicrobium denitrificans. Thus, a biological function was established for the universally conserved cofactor lipoate that is markedly different from its canonical roles in central metabolism. LbpAs likely function as sulfur-binding entities presenting substrate to different catalytic sites of the Hdr-like complex, similar to the substrate-channeling function of lipoate in carbon-metabolizing multienzyme complexes, for example pyruvate dehydrogenase.

SUBMITTER: Cao X 

PROVIDER: S-EPMC6067878 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature