Reversible Formation of Alkyl Radicals at [Fe₄S₄] Clusters and Its Implications for Selectivity in Radical SAM Enzymes.

ABSTRACT: All kingdoms of life use the transient 5'-deoxyadenosyl radical (5'-dAdo•) to initiate a wide range of difficult chemical reactions. Because of its high reactivity, the 5'-dAdo• must be generated in a controlled manner to abstract a specific H atom and avoid unproductive reactions. In radical S-adenosylmethionine (SAM) enzymes, the 5'-dAdo• is formed upon reduction of SAM by an [Fe₄S₄] cluster. An organometallic precursor featuring an Fe-C bond between the [Fe₄S₄] cluster and the 5'-dAdo group was recently characterized and shown to be competent for substrate radical generation, presumably via Fe-C bond homolysis. Such reactivity is without precedent for Fe-S clusters. Here, we show that synthetic [Fe₄S₄]-alkyl cluste

SUBMITTER: Brown AC 

PROVIDER: S-EPMC7447116 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature