title: Rotational catalysis in proton pumping ATPases: from E. coli F-ATPase to mammalian V-ATPase.
abstract: We focus on the rotational catalysis of Escherichia coli F-ATPase (ATP synthase, F(O)F(1)). Using a probe with low viscous drag, we found stochastic fluctuation of the rotation rates, a flat energy pathway, and contribution of an inhibited state to the overall behavior of the enzyme. Mutational analyses revealed the importance of the interactions among β and γ subunits and the β subunit catalytic domain. We also discuss the V-ATPase, which has different physiological roles from the F-ATPase, but is structurally and mechanistically similar. We review the rotation, diversity of subunits, and the regulatory mechanism of reversible subunit dissociation/assembly of Saccharomyces cerevisiae and mammalian complexes. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).
authors.affiliation: Department of Biochemistry, Iwate Medical University, Yahaba, Iwate, Japan. futaim@iwate-med.ac.jp
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Futai
authors.forename: Mayumi
authors.initials: M
authors.lastname: Nakanishi-Matsui
authors.forename: Haruko
authors.initials: H
authors.lastname: Okamoto
authors.forename: Mizuki
authors.initials: M
authors.lastname: Sekiya
authors.forename: Robert K
authors.initials: RK
authors.lastname: Nakamoto
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017434:Protein Structure, Tertiary; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D029701:Saccharomyces cerevisiae Proteins; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases