Fig. 6.

A computer-generated model, shown as a stereo diagram, suggests that the binding of the whole E16 antibody to WNV would leave surface areas accessible to putative receptor binding. The antibody density was calculated from the x-ray coordinates of an IgG (PDB ID code 1IGY) after superpositioning one Fab of the IgG on the fitted Fab E16. The WNV surface is shown in green, and Fab E16 is in blue. The unbound Fab portion of the IgG is colored red, and the Fc portion is yellow. The black triangle marks an icosahedral asymmetric unit. A large portion of the WNV surface is accessible, including the glycan at Asn-154 (red arrow). Severe clashes between antibodies bound to DIII-Bs (forming the outer circle around the icosahedral fivefolds) suggest that only some of the possible binding sites can be occupied simultaneously by the whole E16 antibody. Partial occupancy would leave the area close to the fivefold axes accessible to putative receptor molecules.