Characterization of a Radical SAM Oxygenase for the Ether Crosslinking in Darobactin Biosynthesis.

ABSTRACT: Darobactin A is a ribosomally synthesized, post-translationally modified peptide (RiPP) with potent and broad-spectrum anti-Gram-negative antibiotic activity. The structure of darobactin A is characterized by an ether and C-C crosslinking. However, the specific mechanism of the crosslink formation, especially the ether crosslink, remains elusive. Here, using in vitro enzyme assays, we demonstrate that both crosslinks are formed by the DarE radical S-adenosylmethionine (SAM) enzyme in an O₂-dependent manner. The relevance of the observed activity to darobactin A biosynthesis was demonstrated by proteolytic transformation of the DarE product into darobactin A. Furthermore, DarE assays in the presence of ¹⁸O₂ or [¹⁸O]water demonstrated that t

SUBMITTER: Nguyen H 

PROVIDER: S-EPMC9588720 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature