Thioether bond formation by SPASM domain radical SAM enzymes: C_α H-atom abstraction in subtilosin A biosynthesis

Abstract

AlbA is a radical SAM enzyme catalyzing the formation of three unusual thioether bonds in the antibiotic subtilosin A. We demonstrate here that AlbA catalyzes direct Cα H-atom abstraction and likely contains three essential [4Fe-4S] centers. This leads us to propose novel mechanistic perspectives for thioether bond catalysis by radical SAM enzymes.