Atomic resolution structures of the methane-activating enzyme in anaerobic methanotrophy reveal extensive post-translational modifications.

ABSTRACT: Anaerobic methanotrophic archaea (ANME) are crucial to planetary carbon cycling. They oxidise methane in anoxic niches by transferring electrons to nitrate, metal oxides, or sulfate-reducing bacteria. No ANMEs have been isolated, hampering the biochemical investigation of anaerobic methane oxidation. Here, we obtained the true atomic resolution structure of their methane-capturing system (Methyl-Coenzyme M Reductase, MCR), circumventing the isolation barrier by exploiting microbial enrichments of freshwater nitrate-reducing ANME-2d grown in bioreactors, and marine ANME-2c in syntrophy with bacterial partners. Despite their physiological differences, these ANMEs have extremely conserved MCR structures, similar to homologs from methanogenic Methanosarcinales, rather than the phylogenetically

SUBMITTER: Muller MC 

PROVIDER: S-EPMC12413448 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature