FIGURE 3.

Time courses of rotation of a 0.49-μm polystyrene bead duplex attached to the γ-subunit. (a) Wild-type; (b) γ-Δ14; (c) γ-Δ17; and (d) γ-Δ21. Top time axes apply to [ATP] at 200 nM and above, and bottom axes to 20 nM and 60 nM ATP. Records showing the highest average speed over >7 consecutive revolutions are selected and shown. Insets show the whole time courses, where the selected portions are shown in red. Average rotation frequency in Fig. 4 and torque in Fig. 6 were calculated on such selected portions containing >7 consecutive revolutions. Horizontal lines (solid and dotted) are separated by 120°, and each time course has been adjusted such that frequent pauses fall on a horizontal line.