title: ATP hydrolysis assists phosphate release and promotes reaction ordering in F1-ATPase.
abstract: F1-ATPase (F1) is a rotary motor protein that can efficiently convert chemical energy to mechanical work of rotation via fine coordination of its conformational motions and reaction sequences. Compared with reactant binding and product release, the ATP hydrolysis has relatively little contributions to the torque and chemical energy generation. To scrutinize possible roles of ATP hydrolysis, we investigate the detailed statistics of the catalytic dwells from high-speed single wild-type F1 observations. Here we report a small rotation during the catalytic dwell triggered by the ATP hydrolysis that is indiscernible in previous studies. Moreover, we find in freely rotating F1 that ATP hydrolysis is followed by the release of inorganic phosphate with low synthesis rates. Finally, we propose functional roles of the ATP hydrolysis as a key to kinetically unlock the subsequent phosphate release and promote the correct reaction ordering.
authors.affiliation: Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Japan.
authors.forename: Chun-Biu
authors.initials: CB
authors.lastname: Li
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ueno
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.|PRESTO, Japan Science and Technology Agency, Tokyo 113-8656, Japan.|CREST, Japan Science and Technology Agency, Tokyo 113-8656, Japan.
authors.forename: Rikiya
authors.initials: R
authors.lastname: Watanabe
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.|CREST, Japan Science and Technology Agency, Tokyo 113-8656, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Noji
authors.affiliation: Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Japan.
authors.forename: Tamiki
authors.initials: T
authors.lastname: Komatsuzaki
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D002384:Catalysis; D003198:Computer Simulation; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009010:Monte Carlo Method; D010710:Phosphates / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012399:Rotation; D019415:Torque
chemical_list: D020409:Molecular Motor Proteins; D010710:Phosphates; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases