A real-time NADH-coupled ATPase assay was performed by adding 1 mM ATP (saturating ATP [8]) to start the reaction followed by 50 ng of pUC18 DNA (indicated as a break in the trace). (A) Example traces clearly show that ATBC reduces the rate of ATP consumption by UvrA. The slopes provide the V_max ATP consumption rate. (B) k_cat values were calculated from the known concentration of UvrA. k_cat values in the presence of ATP only are shown in dark bars, and with both ATP and DNA in light bars. ATBC reduces the observed k_cat by ∼70%. Experiments were performed at room temperature in the ABC buffer, no ADP accumulates in this assay. The error bars represent the standard error of the mean (UvrA n = 26, UvrA + ATBC n = 6). *P = 0.0002, **P < 0.0001 (unpaired t-test).