Figure 1. Effects of ATP on HIV-1 RT reaction kinetics.

A. The substrate-velocity curves of purified HIV-1 RTs in the presence of ATP. RNA-dependent DNA polymerase activity [13] of the purified RTs was measured using various concentrations of [α-³²P]dTTP and poly (rA)·p(dT)_12-18 in the presence of ATP. Representative results with 93JP-NH1 RT (left) and ERT-mt6 RT (right) are shown. B. Lineweaver-Burk double-reciprocal plots for ATP-dependent inhibition of dTTP incorporation. Reciprocal values of the initial velocities and substrate concentrations in Figure 1A are plotted. C. Effects of ATP on K_m (left) and k_cat (right) values in RT reaction. The K_m and k_cat values were estimated by fitting of the initial velocity of dTTP incorporation to Equations 3 and 4 as described in Materials and Methods. The mean values with variances of the six independent experiments are shown.