Self-sacrifice in radical S-adenosylmethionine proteins.
The radical SAM superfamily of metalloproteins catalyze the reductive cleavage of S-adenosyl-l-methionine to generate a 5'-deoxyadenosyl radical (5'-dA*) intermediate that is obligate for turnover. The 5'-dA* acts as a potent oxidant, initiating turnover by abstracting a hydrogen atom from an appropriate substrate. A special class of these enzymes use this strategy to functionalize unactivated C-H bonds by insertion of sulfur atoms. This review will describe the characterization of three members of this class - biotin synthase, lipoyl synthase, and MiaB protein - each of which has been shown to cannibalize itself during turnover.
Booker
Squire J
SJ
Department of Chemistry, The Pennsylvania State University, University Park, PA 16803, United States. sjb14@psu.edu
Cicchillo
Robert M
RM
Grove
Tyler L
TL
D029968:Escherichia coli Proteins / Q000378:metabolism; D005609:Free Radicals; D006865:Hydrogenation; D011506:Proteins / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000378:metabolism*; D013466:Sulfurtransferases / Q000378:metabolism
D029968:Escherichia coli Proteins; D005609:Free Radicals; D011506:Proteins; D012436:S-Adenosylmethionine; C499584:MiaB protein, E coli; D013466:Sulfurtransferases; C057985:biotin synthetase