Fig 2. Structure of AM22 in complex with prefusion RSV F.

(A) Crystal structure overview shows three AM22 Fabs bound to the prefusion RSV F trimer, viewed looking along or toward the viral membrane. One RSV F protomer and one AM22 Fab are shown in ribbon representation (left panel), whereas the other protomers and Fabs are shown as molecular surfaces. The AM22 heavy chain is colored purple and the light chain is white. One RSV F protomer is colored green for F1 and blue for F2, whereas the other two RSV F protomers are tan and pink. (B) Close-up of the side and top views in ribbon-and-stick representation, colored as in (A), highlighting the β-sheet hydrogen bond interactions between F1 and the CDR H3 of AM22. The light chain was hidden in the lower-left panel and both panels on the right for clarity. For stick models, oxygen atoms are colored red, nitrogen blue, and sulfur yellow. (C) The amino acid sequence of RSV F site Ø is shown for both strain A2 and strain B9320. Diamond symbols above each residue indicate a contact between AM22 and prefusion RSV F strain A2 based upon PDBePISA analysis of the crystal structure.