Figure 3. Identification of diverse gorilla CD4 alleles.

(A) Eight unique protein variants of gorilla CD4 were identified. The polymorphic sites (red arrows) are shown in the alignment, where dots indicate amino acid residues that are identical to human. (B) The frequencies of the eight alleles encoding unique CD4 protein variants are shown for three gorilla subspecies, Gorilla gorilla gorilla (n = 28), Gorilla beringei graueri (n = 3), and Gorilla gorilla diehli (n = 1). (C) Cryo-EM structure of an HIV-1 Env trimer in complex with human CD4 (PDB 5U1F) visualized in ChimeraX (Goddard et al., 2017). Individual gp120 and gp41 subunits are colored in light and dark blue, respectively. The CD4 D1 domain (red) and D2-D4 domains (gray) are shown, with gorilla nonsynonymous SNPs shown on the human sequence as purple spheres.