The generation of 5′-deoxyadenosyl radicals by adenosylmethionine-dependent radical enzymes

Adenosylmethionine-dependent radical enzymes provide a novel mechanism for generating the highly oxidizing 5'-deoxyadenosyl radical in an anaerobic reducing environment. Recent studies suggest a unique covalent interaction between adenosylmethionine and a catalytic iron-sulfur cluster that may promote inner-sphere electron transfer to the sulfonium, resulting in the reductive cleavage of a C-S bond and the generation of a 5'-deoxyadenosyl radical. The utilization of this radical as a catalytic and stoichiometric oxidant in many different enzyme reactions reflects the broad diversity of radical enzymes throughout biology.