Quinone Catalysis Modulates Proton Transfer Reactions in the Membrane Domain of Respiratory Complex I.

ABSTRACT: Complex I is a redox-driven proton pump that drives electron transport chains and powers oxidative phosphorylation across all domains of life. Yet, despite recently resolved structures from multiple organisms, it still remains unclear how the redox reactions in Complex I trigger proton pumping up to 200 Å away from the active site. Here, we show that the proton-coupled electron transfer reactions during quinone reduction drive long-range conformational changes of conserved loops and trans-membrane (TM) helices in the membrane domain of Complex I from Yarrowia lipolytica. We find that the conformational switching triggers a π → α transition in a TM helix (TM3^ND6) and establishes a proton pathway between the quinone chamber and the antiporter-like subunits, responsible for

SUBMITTER: Kim H 

PROVIDER: S-EPMC10416309 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature