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Updated: Apr 26, 2026

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
Published on: November 22, 2014
Reversible H atom abstraction catalyzed by the radical S-adenosylmethionine enzyme HydG
Benjamin R Duffus1, Shourjo Ghose, John W Peters
1Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Abstract:
The organometallic H-cluster at the active site of [FeFe]-hydrogenases is synthesized by three accessory proteins, two of which are radical S-adenosylmethionine enzymes (HydE, HydG) and one of which is a GTPase (HydF). In this work we probed the specific role of H atom abstraction in HydG-catalyzed carbon monoxide and cyanide production from tyrosine. The isotope distributions of 5'-deoxyadenosine and p-cresol were evaluated using deuterium-labeled tyrosine substrates in H2O and D2O. The observation of multiply deuterated 5'-deoxyadenosine and deuterated S-adenosylmethionine when the reaction is carried out in D2O provides evidence for a 5'-deoxyadenosyl radical-mediated abstraction of a hydrogen atom from a solvent-exchangeable position as a reversible event.
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