Radical S-adenosylmethionine enzyme catalyzed thioether bond formation in sactipeptide biosynthesis.

Sactipeptides represent a new emerging class of ribosomally assembled and posttranslationally modified peptides that show diverse bioactivities. Their common hallmark is an intramolecular thioether bond that crosslink the sulfur atom of a cysteine residue with the α-carbon of an acceptor amino acid. This review summarizes recent achievements concerning the biosynthesis of sactipeptides in general and with special focus on the common enzymatic radical SAM mechanism leading to the thioether linkage formation. In addition this mechanism is compared to the mechanism of thioether bond formation during lanthipeptide biosynthesis and to other radical based thioether bond forming reactions.