FIG 4.

Comparison of seal11 HA antigenic sites with other HA structures. (A) Recognized AS mapped onto the seal11 HA structure, shown as a surface representation and colored individually. (B) Structural comparison of the antigenic sites on the HA molecules between A(H3N8) (avian dkUkr63 and seal11) and seasonal H3N2 (Aichi68 and HK05). Three-dimensional models of the H3 HA molecules of each HA were used and are shown as surface representations. Expanded views of the antigenic sites (A through E) are shown. Amino acids are colored as follows: positive (Arg and Lys), blue; negative (Asp and Glu), red; hydrophobic (Ala, Phe, Gly, Ile, Leu, Met, Val, and Trp), yellow; polar (His, Asn, Gln, Ser, Thr, and Tyr), green.