Figure 4.

Sequence comparison of HIV-1 and HIV-2 Envs. The HIV-1 subtype B infectious molecular clone HXB2 Env gp41 sequence (Database accession number K03455) is aligned to the HIV-2 ROD (M15390) and ISY (J04498) Env gp41 sequences. Amino Acid sites conserved in all 3 sequences are shaded black, and those conserved in 2 of the 3 are shaded grey. Numbering is based on the HXB2 amino acid sequence. The sequences corresponding approximately to the different regions of HIV-1 gp41 have been highlighted as follows: Membrane Anchor (180–203), red; Lentivirus Lytic Peptide-3 (268–286), green; Lentivirus Lytic Peptide-2 (287–313), cyan; Lentivirus Lytic Peptide-1 (326–354), turquoise. Note the lack of homology in LLP-2 and 3 sequences, whereas LLP-1 (337–354) appears to be very homologous between the three strains.