FIGURE 7.
ATP hydrolysis by wild-type and insert-less E. coli gyrase. A, basal ATPase activity plotted as a function of starting ATP concentration in mm (x axis) and nmol of phosphate produced per minute (y axis). Data were fit to an apparent Michaelis-Menten model (Rwt = 0.996; RΔtail = 1.000). B, DNA stimulated ATPase activity plotted as a function of sheared salmon sperm DNA concentration in μm (x axis) and nmol of phosphate produced per minute (y axis). Data were fit to the Hill equation (Rwt = 1.000; RΔtail = 1.000). C, ATPase activity time course. Wild-type and insert-less E. coli gyrase ATPase activities are plotted as a function of nmol phosphate produced (x axis) and time in minutes (y axis). Phosphate produced during a 50-min time course is approaching the saturation point for the assay.