Determinants of Directionality and Efficiency of the ATP Synthase F_o Motor at Atomic Resolution.

ABSTRACT: F_o subcomplex of ATP synthase is a membrane-embedded rotary motor that converts proton motive force into mechanical energy. Despite a rapid increase in the number of high-resolution structures, the mechanism of tight coupling between proton transport and motion of the rotary c-ring remains elusive. Here, using extensive all-atom free energy simulations, we show how the motor's directionality naturally arises from the interplay between intraprotein interactions and energetics of protonation of the c-ring. Notably, our calculations reveal that the strictly conserved arginine in the a-subunit (R176) serves as a jack-of-all-trades: it dictates the direction of rotation, controls the protonation state of the proton-release site, and separates the two proton-access half-channels. Ther

SUBMITTER: Marciniak A 

PROVIDER: S-EPMC8762653 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature