FIG. 2.

Alignment of the sequences of the 29 HIV-1 group O strains used in the phenotypic analysis. The sequences correspond to the ectodomain of gp41; HIV-O sequences are compared with HIV-1_BRU, used as a reference, and are ranked in ascending order of associated IC₅₀. The IC₅₀ threshold of 1,000 nM is indicated by a horizontal line. Resistance-associated positions are boxed, and the residues at positions 27 and 119 are boxed and indicated by arrows. A schematic linear structure of the gp41 ectodomain is shown in the center. FP, fusion peptide; HR1 and HR2, heptad repeats 1 and 2; TM, transmembrane region. The positions of the HR1 and HR2 domains were defined according to reference 9.