title: Effects of an ATP analogue, adenosine 5'-[α-thio]-triphosphate, on F1-ATPase rotary catalysis, torque generation, and inhibited intermediated formation.
abstract: F1-ATPase (F1), an important rotary motor protein, converts the chemical energy of ATP hydrolysis into mechanical energy using rotary motion with extremely high efficiency. The energy-conversion mechanism for this molecular motor has been extensively clarified by previous studies, which indicate that the interactions between the catalytic residues and the β- and γ-phosphates of ATP are indispensable for efficient catalysis and torque generation. However, the role of α-phosphate is largely unknown. In this study, we observed the rotation of F1 fuelled with an ATP analogue, adenosine 5'-[α-thio]-triphosphate (ATPαS), in which the oxygen has been substituted with a sulfur ion to perturb the α-phosphate/F1 interactions. In doing so, we have revealed that ATPαS does not appear to have any impact on the kinetic properties of the motor or on torque generation compared to ATP. On the other hand, F1 was observed to lapse into the ADP-inhibited intermediate states when in the presence of ATPαS more severely than in the presence of ATP, suggesting that the α-phosphate group of ATP contributes to the avoidance of ADP-inhibited intermediate formation.
authors: Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
authors: Ayako
authors: A
authors: Yukawa
authors: Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan; JST, CREST, Tokyo 113-8656, Japan; JST, PRESTO, Tokyo 113-8656, Japan. Electronic address: wrikiya@nojilab.t.u-tokyo.ac.jp.
authors: Rikiya
authors: R
authors: Watanabe
authors: Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan; JST, CREST, Tokyo 113-8656, Japan. Electronic address: hnoji@appchem.t.u-tokyo.ac.jp.
authors: Hiroyuki
authors: H
authors: Noji
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D002417:Cattle; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism
chemical_list: D013438:Sulfhydryl Compounds; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases
keywords: ATP analogue; F(1)-ATPase; F(o)F(1)-ATP synthase; Molecular motor; Single-molecule analysis