Figure 2:

Atomic models of the mature HIV-2 CA lattice assembly.

A, B. Top and side views of the IP6 density in the central pore of the HIV-2 CA hexamer (A) or pentamer (B), along with density for residues R18 and K25 (stick). The helices lining the pore are shown in cartoon representation. C. Cartoon representation of the CA protomer in the hexamer (blue) aligned with previous crystal structures of HIV-2 CA NTD⁴⁰ (beige) and CTD⁴¹ (green). Insets highlight structurally conserved salt bridge between GL-AN D97 and R119 (upper left), cryo-EM density of the CypA-binding loop (upper right), swinging out of the ₁₇₆ǪTD₁₇₈ loop of the CTD upon ordered engagement with NTD in the CA lattice (lower left), and shift of the ₅₈CVGDH₆₂ loop of the NTD and adjacent residues to accommodate adjacent protomer contact (light blue; lower right).