FIGURE 5.

Extension of DNA primers containing 3′-end dCMP and rCMP by HIV-1 RT in macrophage dNTP concentrations. A, diagram of the template (T) and primers (P) used in this experiment. Two 5′-end ³²P-labeled DNA primers containing dCMP or CMP at their 3′ ends were individually annealed to the RNA 40-mer template. These two template-primers were extended by HIV-1 RT (40 nm; green circle), and single nucleotide (dATP) extension time courses were preformed with dTTP for the first nucleotide incorporation. B, the two template-primers were also extended by HIV-1 RT with both dATP and dGTP for the first and second dNTP incorporations at their macrophage concentrations (see Table 1), respectively, from the 3′-end dCMP or rCMP primers. The reactions were conducted for 30, 60, 90, 120, 240, 480, and 720 s. P, unextended primer; E1, one nucleotide extended product; E2, two nucleotide extended products; C, no RT control.