title: Structure of the vacuolar H+-ATPase rotary motor reveals new mechanistic insights.
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.
authors: School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors: Shaun
authors: S
authors: Rawson
authors: School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors: Clair
authors: C
authors: Phillips
authors: Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany.
authors: Markus
authors: M
authors: Huss
authors: Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany.
authors: Felix
authors: F
authors: Tiburcy
authors: Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany.
authors: Helmut
authors: H
authors: Wieczorek
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors: John
authors: J
authors: Trinick
authors: School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors: Michael A
authors: MA
authors: Harrison
authors: School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK. Electronic address: s.p.muench@leeds.ac.uk.
authors: Stephen P
authors: SP
authors: Muench
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020134:Catalytic Domain; D017124:Conserved Sequence; D020285:Cryoelectron Microscopy; D005583:Fourier Analysis; D019476:Insect Proteins / Q000737:chemistry*; D018402:Manduca / Q000201:enzymology*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry*
chemical_list: D019476:Insect Proteins; D025262:Vacuolar Proton-Translocating ATPases