Characterization by ENDOR Spectroscopy of the Iron-Alkyl Bond in a Synthetic Counterpart of Organometallic Intermediates in Radical SAM Enzymes.

ABSTRACT: Members of the radical S-adenosyl-l-methionine (SAM) enzyme superfamily initiate a broad spectrum of radical transformations through reductive cleavage of SAM by a [4Fe-4S]¹⁺ cluster it coordinates to generate the reactive 5'-deoxyadenosyl radical (5'-dAdo^•). However, 5'-dAdo^• is not directly liberated for reaction and instead binds to the unique Fe of the cluster to create the catalytically competent S = 1/2 organometallic intermediate Ω. An alternative mode of reductive SAM cleavage, especially seen photochemically, instead liberates CH₃^•, which forms the analogous S = 1/2 organometallic intermediate with an Fe-CH₃ bond, Ω_M. The presence of a covalent Fe-C bond in both structures was establi

SUBMITTER: Ho MB 

PROVIDER: S-EPMC9529902 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature