Structure of the HC19 antibody in complex with the HA1 domain of Aichi H3N2.

<p>A) 3D structure three fragments of antibody (Fab, blue) bound to the HA1 domains of trimeric HA (brown) of Aichi H3N2 (PDB: 2vir) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159074#pone.0159074.ref026" target="_blank">26</a>]. B) Zoom in on the CDR containing Fab subdomain. Peptides containing the CDR sequences 26–32 (CDR1), 53–55 (CDR2) and 99–110 (CDR3) were entitled PeA (green), PeC (black) and PeB (red) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159074#pone.0159074.ref027" target="_blank">27</a>]. C) PeB interacting with HA in proximity to the sialic acid binding pocket (yellow). Amino acids beneficial for binding are shown in blue, non-favorable amino acids (see <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159074#sec017" target="_blank">Results</a></b>) are shown in black. D) Primary and secondary structures of VH of the Fab fragment. Antibody derived peptides are colored as in B.