Fig. 3.

Structure of virion-associated Env. The structure of HIV Env is presented with the relative localization of a gp120 subunit within the virion-associated trimeric structure. The Env volume is displayed in light grey, while the membrane is darker grey at the bottom of the figure. The figure was constructed using the EM Database files EMD-5019 (Env) and EMD-5022 (membrane) (Liu et al., 2008) and the gp120 co-ordinates from PDB file 2NY7 (Zhou et al., 2007), with gp120 positioned into the EM density map using the ‘Fit in Map’ tool in UCSF Chimera (Pettersen et al., 2004).