title: Crystal structure of A3B3 complex of V-ATPase from Thermus thermophilus.
abstract: Vacuolar-type ATPases (V-ATPases) exist in various cellular membranes of many organisms to regulate physiological processes by controlling the acidic environment. Here, we have determined the crystal structure of the A(3)B(3) subcomplex of V-ATPase at 2.8 A resolution. The overall construction of the A(3)B(3) subcomplex is significantly different from that of the alpha(3)beta(3) sub-domain in F(o)F(1)-ATP synthase, because of the presence of a protruding 'bulge' domain feature in the catalytic A subunits. The A(3)B(3) subcomplex structure provides the first molecular insight at the catalytic and non-catalytic interfaces, which was not possible in the structures of the separate subunits alone. Specifically, in the non-catalytic interface, the B subunit seems to be incapable of binding ATP, which is a marked difference from the situation indicated by the structure of the F(o)F(1)-ATP synthase. In the catalytic interface, our mutational analysis, on the basis of the A(3)B(3) structure, has highlighted the presence of a cluster composed of key hydrophobic residues, which are essential for ATP hydrolysis by V-ATPases.
authors.affiliation: Division of Molecular Biosciences, Imperial College London, South Kensington Campus, London, UK.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Maher
authors.forename: Satoru
authors.initials: S
authors.lastname: Akimoto
authors.forename: Momi
authors.initials: M
authors.lastname: Iwata
authors.forename: Koji
authors.initials: K
authors.lastname: Nagata
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Hori
authors.forename: Masasuke
authors.initials: M
authors.lastname: Yoshida
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
authors.forename: So
authors.initials: S
authors.lastname: Iwata
authors.forename: Ken
authors.initials: K
authors.lastname: Yokoyama
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry; D001407:Bacillus / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D003460:Crystallization; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016963:Thermus thermophilus / Q000201:enzymology* / Q000235:genetics; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D025262:Vacuolar Proton-Translocating ATPases