FIG. 6.

Identification of SIV gp41 residues that participate in interactions with PRA1. Amino acid substitutions were introduced into the SIV gp41 CD in the context of the C-terminal deletion SCD 1-77 and the full-length gp41 cytoplasmic tail (SIV CD) and tested for the ability to associate with PRA1 in mammalian two-hybrid assays. These mutations included a series of consecutive double and triple alanine substitutions (A) and combinations of nonconsecutive alanine, glutamine, and serine substitutions in SCD 1-77 (B) and the full-length SIV gp41 CD (C). Amino acid replacements are indicated as subscripts and correspond to the amino acid sequence shown in Fig. 4B. Error bars indicate the standard deviations of duplicate transfections.