FIG 1.

Structure of H5Nx HA. (A) HA monomer for H5N6 HA (cyan) and H5N8 HA (green). The occupied glycosylation sites, A23, A165, and A286 on HA1 and B154 on HA2, are labeled and are shown as sticks. (B) Comparison of the H5N6 HA RBS (green) with equivalent, overlapping structures from H5N8 HA (cyan) and Anhui HA (magenta). The three structural elements making up the binding site—the 130-loop, the 190-helix, and the 220-loop—are labeled. Conserved residues are shown as green sticks. The amino acids discussed in the text are shown as orange sticks. All structural figures were generated with MacPyMol (75).