FIG. 8.

Comparisons of the locations of the mutations induced by NBD-556 between the structures of unliganded and liganded gp120. The side chains of the mutated residues that appeared during in vitro selection with NBD-556 are shown in yellow, green and purple in the liganded (left) or unliganded (right) structures. The amino acid substitutions that confer resistance in HIV-1 are indicated in purple (S375N and A433T). The crystal structures of liganded and unliganded gp120 were retrieved from the PDB (entries 1RZJ and 2BF1, respectively). The corresponding sites of the NBD-resistant mutations are also shown on the unliganded gp120.