Figure 2.

In vitro motility–sliding velocity. The sliding velocity was similar to WT for both mutants in the absence of load. The presence of G440A MV (nonhydrolyzing mutant) was used as a tethering load in the loaded in vitro motility assay. A, the average velocity of all of the filaments (moving and nonmoving) was determined and plotted as a function of the fraction of G440A MV present relative to the total MV added to the assay. B, the number of stuck filaments was determined and plotted as a function of the fraction of G440A. C, the velocity of only the moving filaments was plotted as a function of G440A fraction. Significant differences of the mutants compared with the WT are indicated by asterisks (*, p < 0.05; **, p < 0.005; n = 4).