Effect of external torque on the ATP-driven rotation of F1-ATPase

Takahiro Watanabe-Nakayama, Shoichi Toyabe, Seishi Kudo, Shigeru Sugiyama, Masasuke Yoshida, Eiro Muneyuki

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

F1-ATPase is a rotary molecular motor powered by the torque generated by another rotary motor F0 to synthesize ATP in vivo. Therefore elucidation of the behavior of F1 under external torque is very important. Here, we applied controlled external torque by electrorotation and investigated the ATP-driven rotation for the first time. The rotation was accelerated by assisting torque and decelerated by hindering torque, but F1 rarely showed rotations in the ATP synthesis direction. This is consistent with the prediction by models based on the assumption that the rotation is tightly coupled to ATP hydrolysis and synthesis. At low ATP concentrations (2 and 5 μM), 120° stepwise rotation was observed. Due to the temperature rise during experiment, quantitative interpretation of the data is difficult, but we found that the apparent rate constant of ATP binding clearly decreased by hindering torque and increased by assisting torque.

Original languageEnglish
Pages (from-to)951-957
Number of pages7
JournalBiochemical and biophysical research communications
Volume366
Issue number4
DOIs
Publication statusPublished - 2008 Feb 22

Keywords

  • External force
  • F-ATPase
  • Molecular motor
  • Single molecule
  • Tight coupling

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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