Referenced in: none

Automatically associated channels: Slo1

Title: Structure of the Vacuolar H(+)-ATPase Rotary Motor Reveals New Mechanistic Insights.

Authors: Shaun Rawson, Clair Phillips, Markus Huss, Felix Tiburcy, Helmut Wieczorek, John Trinick, Michael A Harrison, Stephen P Muench

Journal, date & volume: Structure, 2015 Mar 3 , 23, 461-71

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25661654

Abstract
Vacuolar H(+)-ATPases are multisubunit complexes that operate with rotary mechanics and are essential for membrane proton transport throughout eukaryotes. Here we report a ∼ 1 nm resolution reconstruction of a V-ATPase in a different conformational state from that previously reported for a lower-resolution yeast model. The stator network of the V-ATPase (and by implication that of other rotary ATPases) does not change conformation in different catalytic states, and hence must be relatively rigid. We also demonstrate that a conserved bearing in the catalytic domain is electrostatic, contributing to the extraordinarily high efficiency of rotary ATPases. Analysis of the rotor axle/membrane pump interface suggests how rotary ATPases accommodate different c ring stoichiometries while maintaining high efficiency. The model provides evidence for a half channel in the proton pump, supporting theoretical models of ion translocation. Our refined model therefore provides new insights into the structure and mechanics of the V-ATPases.