Molecular Basis of the Electron Bifurcation Mechanism in the [FeFe]-Hydrogenase Complex HydABC.

ABSTRACT: Electron bifurcation is a fundamental energy coupling mechanism widespread in microorganisms that thrive under anoxic conditions. These organisms employ hydrogen to reduce CO₂, but the molecular mechanisms have remained enigmatic. The key enzyme responsible for powering these thermodynamically challenging reactions is the electron-bifurcating [FeFe]-hydrogenase HydABC that reduces low-potential ferredoxins (Fd) by oxidizing hydrogen gas (H₂). By combining single-particle cryo-electron microscopy (cryoEM) under catalytic turnover conditions with site-directed mutagenesis experiments, functional studies, infrared spectroscopy, and molecular simulations, we show that HydABC from the acetogenic bacteria Acetobacterium woodii and Thermoanaerobacter kivui empl

SUBMITTER: Katsyv A 

PROVIDER: S-EPMC10021017 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature