Fig. 4

Mutations of Glutamic acid 560 (E560) in the HR1 modeled in Env trimers. The supposed residues which are associated with HR1 are modeled in the CD4- and 17b-liganded Env SOSIP trimer (PDB code: 5VN3). The CD4 molecules are colored red and 17b are colored cyan. Each protomer of gp120 and gp41 are colored green and purple, blue and skyblue, and wheat and yellow, respectively. The residues in gp120 are colored green or wheat, and the residues in gp41 are colored yellow. The view of the topological layers in the gp120 inner domain and gp41 HR1 region highlight the residues in gp120 that located in and around its potential interaction sites with the residue at position 560 of gp41. The following residues belong to different layers: L52, F53, H72, A73, and P79 in layer 1; A221, G222, and F223 in layer 2. The residues between I548 and Q562 are not observed in this model