Mechanism of Reduction of an Aminyl Radical Intermediate in the Radical SAM GTP 3',8-Cyclase MoaA.

ABSTRACT: The diversity of the reactions catalyzed by radical S-adenosyl-l-methionine (SAM) enzymes is achieved at least in part through the variety of mechanisms to quench their radical intermediates. In the SPASM-twitch family, the largest family of radical SAM enzymes, the radical quenching step is thought to involve an electron transfer to or from an auxiliary 4Fe-4S cluster in or adjacent to the active site. However, experimental demonstration of such functions remains limited. As a representative member of this family, MoaA has one radical SAM cluster ([4Fe-4S]_RS) and one auxiliary cluster ([4Fe-4S]_AUX), and catalyzes a unique 3',8-cyclization of GTP into 3',8-cyclo-7,8-dihydro-GTP (3',8-cH₂GTP) in the molybdenum cofactor (Moco) biosynthesis. Here, we re

SUBMITTER: Pang H 

PROVIDER: S-EPMC8415136 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature