Figure 5.

Backward steps in ATP-driven rotation of Arg-finger mutant EhV₁ in the presence of ADP. A, typical time course of rotation at 3 mm ATP in the presence of 10 mm ADP. The black arrowheads indicate the backward steps, and the black arrows indicate the 240° forward steps due to the alternative pathways as observed in TF₁. The x-y trajectory and the expanded time course are shown in insets. In the expanded time course, the regions of red and blue indicate the angular position of the main pause and the subpause, respectively. B, the schematic of backward and recovery steps. The pauses before the −80° backward step (green lines), before the +80° recovery step after the −80° backward step (purple), before the −40° backward step (orange), before the +40° recovery step (red), and before the +80° recovery step after the +40° recovery step (blue) are shown. C, [ADP] dependences of time constants, mean and median values of the pauses shown in B at 3 mm ATP in the presence of 3, 10, and 30 mm ADP. D, [ATP] dependences of time constants, mean and median values of the pauses shown in B at 0.1, 0.3, and 1 mm ATP in the presence of 10 mm ADP. The distributions of pause durations are shown in Fig. S5. Error bars, S.D.