Fig. 5.

Structural conservation of the motavizumab epitope. The motavizumab epitope on the postfusion RSV F ΔFP glycoprotein exists in a conformation that is very similar to that of the motavizumab-bound peptide. A model of motavizumab bound to RSV F ΔFP suggests that motavizumab contacts residues on two protomers in the trimer. (A) Least-squares superposition of residues 255 to 276 from RSV F ΔFP (tan) and the motavizumab-bound peptide structure (gray) (29) (PDB ID 3IXT) as viewed by the antibody. Side chains of residues that contact motavizumab in the peptide-bound structure are shown as sticks. Oxygen atoms are colored red; nitrogen atoms are blue. (B) Model of motavizumab bound to RSV F ΔFP based on the alignment in panel A. The motavizumab heavy chain is colored green, and the light chain is colored blue. RSV F ΔFP residues 254 to 277 are colored red. (C) Close-up of motavizumab binding to RSV F ΔFP. The helix-loop-helix epitope (red) resides in the tan protomer, whereas Asn454 and Lys465 are from the pink protomer.