title: Radical SAM enzymes in methylation and methylthiolation.
abstract: Radical S-adenosyl-l-methionine (SAM) enzymes are a large and diverse superfamily with functions ranging from enzyme activation through a single H atom abstraction to complex organic and metal cofactor synthesis involving a series of steps. Though these enzymes carry out a variety of functions, they share common structural and mechanistic characteristics. All of them contain a site-differentiated [4Fe-4S] cluster, ligated by a CX(3)CX(2)C or similar motif, which binds SAM at the unique iron. The [4Fe-4S](1+) state of the cluster reductively cleaves SAM to produce a 5'-deoxyadenosyl radical, which serves to initiate the diverse reactions catalyzed by these enzymes. Recent highlights in the understanding of radical SAM enzymes will be presented, with a particular emphasis on enzymes catalyzing methylation and methythiolation reactions.
authors.affiliation: Department of Chemistry and Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Rachel U
authors.initials: RU
authors.lastname: Hutcheson
authors.forename: Joan B
authors.initials: JB
authors.lastname: Broderick
mesh_terms: D008745:Methylation; D008958:Models, Molecular; D011496:Protein Methyltransferases / Q000737:chemistry* / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000737:chemistry* / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D012436:S-Adenosylmethionine; D011496:Protein Methyltransferases