Table 1.

Representation of the steps in the sequential relay mechanism of rotation in F1-ATPase

θiθf (°)β1subunitβ2subunitβ3subunit
080ATP bindingADP release*ATP in pocket
80120ATP in pocketPi releaseATP hydrolysis
120200ATP in pocketATP bindingADP release*
  • In the stator ring the β1, β2, β3 order is counter clockwise as viewed from the rotor side. Key subunit for the step are in boldface. The “ATP, ADP and Pi in pocket” fields correspond to no ligand change during this step.

  • * ADP release is irreversible in these experiments and does not affect the outcome of stalling experiments.

  • We neglect the effect of the coupling of the hydrolysis cleavage reaction to rotor.

  • This transition is identical to that of θi=0° (first row) if the ring is rotated by 120° counter clockwise.