FIG. 3.

The location of the mutations in the BaL envelope gene selected with maC36 and maC46. Black bars indicate the positions of mutations that were identified after maC36 selection (boxed) (19) and maC46 selection (gray shading). The amino acid numbering refers to gp160 of the HIV-1 HXB2 strain. The envelope protein has been subdivided into specific regions. In the gp120 subunit, the signal peptide (SP) and constant (C1 to C5) and variable (V1 to V5) regions are marked, while in the gp41 subunit the fusion peptide (FP), NHR, CHR, membrane proximal region (MPR), membrane-spanning domain (MSD), and cytoplasmatic tail (CT) are highlighted.