FIG. 2.

Inhibition of polymerase activity by AZTTP and 3TCTP. The four HIV-1 RTs used in the subsequent experiments (wild-type [WT], M184V, AZT-21, and M184V/AZT-21) were tested for inhibition by AZTTP and 3TCTP. To simplify the comparisons, the activities of each of the enzymes were normalized to 100%. Various concentrations of AZTTP and 3TCTP were added to polymerization reactions containing a −47 sequencing primer annealed to an M13mp18 DNA template (see Materials and Methods). After 30 min, the reactions were stopped by the addition of trichloroacetic acid and the newly synthesized DNA was collected on Whatman GF/C filters. Panel A shows the effects of adding AZTTP to the polymerization reactions; panel B shows the effects of adding 3TCTP.