Figure 4.

ATP hydrolysis by disulfide-cross-linked variants. A, basal rates of ATP hydrolysis by disulfide-cross-linked variants and wild-type HslU. Assays contained 0.3 μm HslU or pseudohexamers and 5 mm ATP. Values are averages of at least three replicates ± 1 S.D. (error bars). B, basal ATP hydrolysis rates for disulfide-cross-linked pseudohexamers plotted as a function of the number of W subunits. C, rates of ATP hydrolysis determined in the presence of 0.9 μm HslV dodecamer (other conditions as in A). The numbers above each bar represent the rate in the presence of HslV divided by the rate in the absence of HslV.