title: Structural comparison of F1-ATPase: interplay among enzyme structures, catalysis, and rotations.
abstract: F(1)-ATPase, a rotary motor powered by adenosine triphosphate hydrolysis, has been extensively studied by various methods. Here, we performed a systematic comparison of 29 X-ray crystal structures of F(1)-complexes, finding fine interplay among enzyme structures, catalysis, and rotations. First, analyzing the 87 structures of enzymatic αβ-subunits, we confirmed that the two modes, the hinge motion of β-subunit and the loose/tight motion of the αβ-interface, dominate the variations. The structural ensemble was nearly contiguous bridging three clusters, αβ(TP), αβ(DP), and αβ(E). Second, the catalytic site analysis suggested the correlation between the phosphate binding and the tightening of the αβ-interface. Third, addressing correlations of enzymatic structures with the orientations of the central stalk γ, we found that the γ rotation highly correlates with loosening of αβ(E)-interface and β(DP) hinge motions. Finally, calculating the helix 6 angle of β, we identified the recently observed partially closed conformation being consistent with β(HC).
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Kei-ichi
authors.initials: K
authors.lastname: Okazaki
authors.forename: Shoji
authors.initials: S
authors.lastname: Takada
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D055162:Biocatalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D030562:Databases, Protein; D006801:Humans; D008958:Models, Molecular; D025341:Principal Component Analysis; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism
chemical_list: D021122:Protein Subunits; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases