Abstract
We have examined amino acid substitutions at residues 115 and 116 in the reverse transcriptase (RT) of HIV-1. A number of properties were examined, including polymerization and processivity on both DNA and RNA templates, strand displacement, ribonucleotide misincorporation, and resistance to nucleoside analogs. The RT variants Tyr-115–Phe and Phe-116–Tyr are similar to wild-type HIV-1 RT in most, but not all, respects. In contrast, the RT variant Tyr-115–Val is significantly impaired in polymerase activity compared with wild-type RT; however, Tyr-115–Val is able to incorporate ribonucleotides as well as deoxyribonucleotides during polymerization and is resistant to a variety of nucleoside analogs.