Cryo-EM and MD infer water-mediated proton transport and autoinhibition mechanisms of V_o complex.

ABSTRACT: Rotary vacuolar adenosine triphosphatases (V-ATPases) drive transmembrane proton transport through a V_o proton channel subcomplex. Despite recent high-resolution structures of several rotary ATPases, the dynamic mechanism of proton pumping remains elusive. Here, we determined a 2.7-Å cryo-electron microscopy (cryo-EM) structure of yeast V_o proton channel in nanodisc that reveals the location of ordered water molecules along the proton path, details of specific protein-lipid interactions, and the architecture of the membrane scaffold protein. Moreover, we uncover a state of V_o that shows the c-ring rotated by ~14°. Molecular dynamics simulations demonstrate that the two rotary states are in thermal equilibrium and depict how the protonation state of e

SUBMITTER: Roh SH 

PROVIDER: S-EPMC7541076 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature