Figure 2

Surface representation of HA protein. Amino acids associated with antigenic sites (Sb and Ca) and N-glycosylation are highlighted in orange in (A) side view of HA trimers, (B) side view of HA monomer, (C) top view of HA trimers and (D) top view of HA monomer. Sialic acid is shown in green. Figures were generated by Discovery Studio Visualizer-Accelrys.