FIG. 2.

(color). The torque-speed relationship (TSR) of the E. coli flagellar motor. Rotation speed is measured with beads of various loads (data points) attached to a flagellar stub, under different pH conditions (colors) [5]; solid curves: model fits. Inset: Total torque vs speed from [6], normalized by the number of stators. Data collapse indicates that stators contribute independently and additively to the total torque. Solid curve: model TSR for a single stator using the same parameters as in the main figure and Fig. S2 [17], with the temperature fit as 21 °C and the stall torque fit as 300 pN · nm.