Figure 6.

ATP-mediated excision of AZTMP from DNA/DNA template–primers by HIV-1 RT mutants D67N/K70R and D67N/K70R/K73M. Assays were carried out with 38/25-mer DNA–DNA complexes (sequences shown below the upper panel). The inhibitor was first incorporated at position +1 (indicated with an asterisk) of the 25-nucleotide primer (lane P) to generate a 26-nucleotide product (lane B). Excision of the inhibitor and further primer extension in the presence of 3.2 mm ATP and a mixture of dNTPs led to the formation of a fully extended 38-nucleotide product. Aliquots were removed 2, 4, 6, 8, 10, 12, 15, and 20 min after the addition of ATP. Time courses of the excision reactions are shown below. All dNTPs in the assays were supplied at 100 μm, except for dATP whose concentration was 1 μm. Template–primer and active RT concentrations in these assays were 30 and 24 nm, respectively. Represented values (means ± S.D. error bars) were obtained from at least three independent experiments.