Figure 5

Alignment of the NA domain of the 2009 H1N1 strain with the sequences in crystal structures of H5N1 avian flu as well as H1N1 from the 1918 Spanish flu. Residues within 3 Å of the bound drug are indicated with "#", while residues that are different in the new strain compared to both other structures are marked with "@".Intra-strain variation (Flex [AA] in the first annotation line) is displayed as the respective mutated residue in capital letters if found in multiple patients (e.g. D for the N248D substitution) or lower-case (e.g. "i" for V241I) for single occurrences. In the second annotation row, antigenic regions are labelled as "*". Residues with < 3 Å contact to antibodies are labelled "A" for interactions derived from PDB:1ncb, "B" from both PDB:1ncb and PDB:1nmb, "C" from PDB:1nmb and "D" from PDB:2aep.