FIG 5.

Representative NS1 sequence alignments from H5N1 influenza viruses obtained from infected individuals. Shown are 20 representative sequences of H5N1 NS1 encoded in influenza viruses obtained from infected individuals. The accession ID number is shown at the far left side of each sequence. The first sequence (AF084285) belongs to an H5N1 NS1 that does not contain the 5-aa residue deletion at the LR. Note that this is a Hong Kong strain isolated in 1997 (residues 50 to 99 are numbered above and shown in black). The remaining 19 sequences depict how the NS1 sequence from influenza A virus strains isolated after 2000 contain an NS1 with residues 80 to 84 deleted at the linker region (because of this deletion, the remaining sequence has been renumbered and is shown above the sequences). Residue 71 is highlighted by a rectangular box to emphasize the consensus E71 found in most H5N1 NS1s. The boldface NS1 sequences that contain a glycine at position 71 (AY818147 and EF511457) belong to the A/VietNam/1203/2004(H5N1) and A/VietNam/1204/2004(H5N1) influenza viruses, respectively. The search criteria used in the Influenza Research Database (51) included a search for protein NS1 of virus type A, human hosts, all geographic groupings, and H5N1 subtype, with removal of duplicate sequences, and no date restrictions were placed on the search.