Structural Insights into Thioether Bond Formation in the Biosynthesis of Sactipeptides.

ABSTRACT: Sactipeptides are ribosomally synthesized peptides that contain a characteristic thioether bridge (sactionine bond) that is installed posttranslationally and is absolutely required for their antibiotic activity. Sactipeptide biosynthesis requires a unique family of radical SAM enzymes, which contain multiple [4Fe-4S] clusters, to form the requisite thioether bridge between a cysteine and the α-carbon of an opposing amino acid through radical-based chemistry. Here we present the structure of the sactionine bond-forming enzyme CteB, from Clostridium thermocellum ATCC 27405, with both SAM and an N-terminal fragment of its peptidyl-substrate at 2.04 Å resolution. CteB has the (β/α)₆-TIM barrel fold that is characteristic of radical SAM enzymes, as well as a C-terminal SPASM domain t

SUBMITTER: Grove TL 

PROVIDER: S-EPMC6443407 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature