FIG. 2.

Alignment of MLV and HIV-1 RT sequences. The sequences of Moloney MLV (Mo-MLV) and HIV-1 RT were aligned in regions flanking mutations known to confer resistance to one or more drugs. The murine RCR used in these studies was sequenced and found to be identical to the Moloney sequence in these regions (data not shown). (A) 3TC resistance mutation occurs at amino acid 184 of HIV (shaded box); the sequence of the Moloney RT in this region is identical to that of 3TC-resistant HIV-1. (B) d4T resistance mutation occurs at amino acid 75 of HIV (shaded box). The sequence of MLV RT in the homologous position differs from wild-type HIV at several residues in this region.