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Reversible H atom abstraction catalyzed by the radical S-adenosylmethionine enzyme HydG.

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.

SUBMITTER: Duffus BR

PROVIDER: S-EPMC4183638 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

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Reversible H atom abstraction catalyzed by the radical S-adenosylmethionine enzyme HydG.

Duffus Benjamin R BR Ghose Shourjo S Peters John W JW Broderick Joan B JB

Journal of the American Chemical Society 20140910 38

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 observa ...[more]

PMID: 25099480

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