Forced rotation of Na+-driven flagellar motor in a coupling ion-free environment

Shigeru Sugiyama, Yukio Magariyama, Seishi Kudo

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Rotational characteristics of Na+-driven flagellar motor in the presence and absence of coupling ion were analyzed by electrorotation method. The motor rotated spontaneously in the presence of Na+, and the rotation accelerated or decelerated following the direction of the applied external torque. The spontaneous motor rotation was inhibited by removal of external Na+, however, the motor could be forcibly rotated by relatively small external torque applied by the electrorotation apparatus. The observed characteristic of the motor was completely different from that of ATP-driven motor systems, which form rigor bond when their energy source, ATP, is absent. The internal resistance of the flagellar motor increased significantly when the coupling ion could not access the inside of the motor, suggesting that the interaction between the rotor and the stator is changed by the binding of the coupling ion to the internal sites of the motor.

Original languageEnglish
Pages (from-to)32-36
Number of pages5
JournalBiochimica et Biophysica Acta - Bioenergetics
Issue number1
Publication statusPublished - 2004 May 12
Externally publishedYes


  • 2-amino-2-hydroxymethyl-1,3- propandiol
  • CCCP
  • Coupling ion
  • Electrorotation
  • Flagellar motor
  • Torque generation
  • Tris
  • carbonylcyanide-m-chlorophenylhydrazone
  • revolutions per second
  • rps

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology


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