An Abundant and Diverse New Family of Electron Bifurcating Enzymes With a Non-canonical Catalytic Mechanism.

ABSTRACT: Microorganisms utilize electron bifurcating enzymes in metabolic pathways to carry out thermodynamically unfavorable reactions. Bifurcating FeFe-hydrogenases (HydABC) reversibly oxidize NADH (E'∼-280 mV, under physiological conditions) and reduce protons to H₂ gas (E°'-414 mV) by coupling this endergonic reaction to the exergonic reduction of protons by reduced ferredoxin (Fd) (E'∼-500 mV). We show here that HydABC homologs are surprisingly ubiquitous in the microbial world and are represented by 57 phylogenetically distinct clades but only about half are FeFe-hydrogenases. The others have replaced the hydrogenase domain with another oxidoreductase domain or they contain additional subunits, both of which enable various third reactions to be reversibly coupled to NAD⁺

SUBMITTER: Schut GJ 

PROVIDER: S-EPMC9304861 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature