Figure 4. Crystal structure of the BG505 SOSIP.664 trimer in complex with Fab 3H+109L and Fab 35O22.

(A) A ribbon representation of the ternary complex of Fab 3H+109L (orange and brown for heavy and light chains, respectively) and Fab 35O22 (light gray and dark gray for heavy and light chains, respectively) bound to an Env protomer (gp120 is in light blue with N137 deleted from the trimer, and gp41 in green), and with the glycans represented as spheres. (B) Superimposition of 3H+109L with PGT122 (on top) and with PGT124 (center), and PGT122 with PGT124 (bottom) on the BG505 SOSIP.664 trimer to show their relative dispositions. Only the CDR loops and LFR3 of 3H+109L (in orange) and PGT122 (in gray) are shown. Right, schematic representation of the relative rotation in degrees (°) of the F_V regions of the different Abs on the epitope surface. (C) Superimposition of the structures of the three complexes based on the gp120 subunits only (in ribbon representation), with the variable region of each Ab represented as a solid surface and the glycans in spheres. The vertical axes that point towards the center of epitope were used to calculate the comparative tilt angle for each Ab in relation to each other.