Fig. 4

Cryo-EM reconstruction and model of the BG505.SOSIP.664 trimer in complex with BF520.1 Fab. a Side (above) and top (below) views of the cryo-EM reconstruction and structural model. A single monomer consisting of gp120 (orange) and gp41 (dark cyan), and the BF520.1-Fv variable heavy chain (dark blue) and variable light chain (aquamarine) are highlighted. Glycans removed for clarity. The BG505.SOSIP trimer structure 5ACO.pdb docked into the new EM density map with a correlation score of 0.8602³⁴. A global search yielded a preferred placement of the BF520.1 Fv model into the Fab density with a correlation score of 0.8513 (Supplementary Fig. 5g). b Expanded view of the VH domain and gp120. Shown are the conserved gp120 GDIR sequence (purple), glycans N332 and N301, and CDRH loops (green). Mutations that confer potent neutralization (red) are indicated. c Expanded view of the VL domain and the N332 glycan. CDRL loops (yellow) and mutations that conferred potent neutralization (red) are highlighted