FIGURE 1.

The dNTP concentration dependence of the processivity of M184I and M184A HIV-1 RTs. A, the processivity assays of the RT proteins were performed at dNTP concentrations of 5, 50, 100, and 200 μm each. The substrates used for the processivity assays were made by annealing a 5′-end-labeled DNA primer to a 520-nt RNA template (see “Experimental Procedures”). Equivalent amounts of each RT protein normalized by specific activity were prebound to the substrate, and the reaction was initiated by addition of Mg²⁺, dNTPs, and the oligo(dT)-poly(rA) trap. Each reaction was performed in duplicate and terminated at 20 min. B, for the trap control, the reaction conditions were the same as for the processivity assay except the oligo(dT)-poly(rA) trap was added before RT addition. Only the reaction at 100 μm of each dNTP is shown. C, the extension reaction was also performed without the trap mix under the same reaction conditions. Only the reaction at 100 μm of each dNTP is shown. L, 25-bp DNA ladder.