Colibactin's Cyclopropane Moiety Derived from SAM

Our recent Nature Chemical Biology paper reports an exciting new use for the versatile cofactor S-adenosylmethionine (SAM)! We have identified an unusual nonribosomal peptide synthetase that utilizes SAM for amide bond formation and subsequent cyclopropanation, revealing a novel biosynthetic route to the functional group that likely mediates colibactin's genotoxicity. Congratulations to Li, Yindi, and Matt; and thank you to our collaborators Matthew Henke and Neil Kelleher!