Figure 3.

Strand-displacement activity of wild-type (WT) and mutant HIV-1 RTs. The PBS DNA oligonucleotide was end-labeled with [γ³²P]ATP and annealed to sense single-strand DNA. A 10-fold excess of unlabeled DNA oligonucleotides also was annealed to the sense-strand DNA to provide the targets to be displaced. The RT polymerization reaction was done in the presence of two different concentrations of KCl: 75 mM KCl (A) and 35 mM KCl (B). The 5′ end of the first unlabeled target DNA oligonucleotide (marked at the right) indicates the starting point for strand displacement. Duplicate assays, labeled 1 and 2, were done for each sample.