Fig 2.

Protein sequence alignments of RT and IN. Reference amino acid sequences of SRV-4 (GenBank accession number NC_014474.1), HIV-1 (accession number NC_001802.1), MoMLV (accession number NC_001501.1), and FIV (accession number NC_001482.1) were aligned by using the program Clustal W, and the regions corresponding to the RT-polymerase domain (residues 63 to 234) (A) and the IN catalytic core domain (residues 50 to 212) (B) of HIV-1 are shown. The amino acid numbering of SRV-4 IN is based on that of SRV-3 (68). Absolutely conserved residues and conserved substitutions are shown in black and gray boxes, respectively. For symbols above the sequences, closed circles indicate residues associated with drug resistance for HIV-1, and asterisks indicate catalytic residues.