Terminal Electron-Proton Transfer Dynamics in the Quinone Reduction of Respiratory Complex I.

ABSTRACT: Complex I functions as a redox-driven proton pump in aerobic respiratory chains. By reducing quinone (Q), complex I employs the free energy released in the process to thermodynamically drive proton pumping across its membrane domain. The initial Q reduction step plays a central role in activating the proton pumping machinery. In order to probe the energetics, dynamics, and molecular mechanism for the proton-coupled electron transfer process linked to the Q reduction, we employ here multiscale quantum and classical molecular simulations. We identify that both ubiquinone (UQ) and menaquinone (MQ) can form stacking and hydrogen-bonded interactions with the conserved Q-binding-site residue His-38 and that conformational changes between these binding modes modulate the Q redox potentials and th

SUBMITTER: Gamiz-Hernandez AP 

PROVIDER: S-EPMC6300313 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature