Extended Data Fig. 6: Details of the primate immunodeficiency viruses conserved features.
a, An additional disulfide was observed in one branch which placed cys at residues 165 and 168, stabilizing the turn between the B and C strands of V1V2. b, Disulfides observed in the hypervariable V1 loop are highlighted in purple. Due to poor alignment confidence in this region the sequences are shown from residue cys157 conserved in all viruses in the tree. c, The HIV-2 glycan shield is modeled as in Fig. 5e with minor deviations from SIVmac239. d, The fusion peptide region of SIVmac239 adopts a helical structure and abuts the core of the Env contrary to the flexible conformations observed in HIV-1 Env (BG505, PDB ID: 5FYL). We note that the FP is one residue longer in the viruses more proximal to HIV-1.
