Analysis of amino insertion mutations in the fingers subdomain of HIV-1 reverse transcriptase.

In response to dideoxy inosine/hydroxyurea dual therapy, HIV-1 (human immunodeficiency virus type-1) variants were isolated that had a small amino acid insertion and flanking amino acid substitutions in the fingers subdomain of HIV-1. We have analyzed the reverse transcriptase variants for their effects on HIV-1 reverse transcriptase activity. The data suggests that the inserted amino acid residues are responsible for low-level resistance to the nucleoside analog ddITP, while the role of the flanking amino acid substitutions is to compensate for the deleterious effects of the insertion.