CD4 protein structure with domains

Figure. CD4 domain (D1-D4) homology model highlighting sites of positive selection in Simiiformes. This model was created using AlphaFold and visualized on Chimera. The sites of positive selection are colored in white, and they are all found to be in D1 (red) domain at codons 80 and 91. The remaining domains are D2 (blue), D3 (cyan), and D4 (blue). Due to this finding, these sites may potentially be involved in arms race with SIV.