Figure 1: The epitopes of four classes of bNMAb. Currently, there are four broad classes of bNMAb against the HIV-1 trimeric spike (red): Ab that bind the membrane proximal region (blue), the CD4bs (yellow), the oligomannose patch on the outer domain with or without implication of the V3 loop (green) and the V1/V2 domain (brown). Representatives of each class have been extensively structurally characterised. Here, these are shown alongside a low-resolution cryo-EM map of the unliganded gp160 spike (EMDID: 5019) (red mesh) oriented with the viral membrane on the top. In the gp41 portion, the two bNMAb that recognize the membrane proximal region are shown: 4E10 (PDBID: 2FX7) and 2F5 (PDBID:1TJG). Beneath that, in the gp120 portion, are bNMAb that recognize the CD4bs: VRC01 (PDBID: 3NGB), PG04 (PDBID: 3SE9) and b12 (PDBID: 2NY7). Also in the gp120 portion are bNMAb that bind the outer domain region around the V3 loop: 2G12 (PDBID: 1OP5) and PGT128 (PDBID: 3TYG). Finally at the bottom is a bNMAb that binds a quaternary-fold-dependent epitope in the V1/V2 domain: PG9 (PDBID 3U2S). Here, all structures are displayed in cartoon format with the heavy chains of the Ab coloured cyan, the light chains coloured magenta, the gp120 protein portions coloured red and the gp120 glycan portions coloured green.