Time course of ATP hydrolysis by WT, Cys-less, and V32C/A268C lock mutant complexes. The complexes were incubated at 25 °C for 10 min in the presence of 50 μm MgADP in advance. 10 μg of the complexes were added into the assay mixture at 25 s after starting the measurement (down arrow): black line, WT; red line, Cys-less; blue line, unlocked V32C/A268C; purple line, locked V32C/A268C.