(a) Pause-free translocation velocity versus opposing force at various [ATP], 5 µM ADP, and 5 µM Pi. Error-bars represent the SEM. (b) Hill coefficient derived from fitting translocation velocity versus [ATP] at various opposing forces. Error bars represent the standard error of the fit (SEF). (c) Pause-free velocity versus opposing force compiled from data at 5, 3, and 2 mM ATP. Error-bars represent the SEM. Gray and blue curves represent fits to the two different models depicted in the inset. Analytic expressions and fit parameters for the models are given in Figure 2—figure supplement 2. (d) Generalized kinetic cycle for an ATPase subunit. The first block consists of all rate constants k±1, k±2, … up to the first irreversible transition kj (purple). The second block comprises the remaining rate constants (green). (e) Pause-free velocity versus opposing force at various [ADP] and 3 mM ATP. (f) Vmax and KM values as a function of [ADP] at low opposing force (5 pN). Solid lines are fits to a competitive inhibition model, Ki = 129 ± 19 μM. Error-bars represent the SEF. (g) Pause-free velocity versus opposing force under high [Pi] conditions and 3 mM ATP. Error bars represent the SEM.