Fig 3.

Conservation of likely SUMOylation sites in PR8 NS1 among human H1N1 and H3N2 influenza virus strains and influenza virus isolates representing sporadic bird-to-human transmission events. (A) Conservation of the two putative SUMOylation sites identified by SUMOsp2.0 and SUMOplot analyses of PR8 NS1 (K70 and K219) and a previously identified SUMOylation site in a highly pathogenic avian influenza virus (K221), among H1N1 and H3N2 human influenza virus strains. The numbers in parentheses indicate the total number of sequences analyzed for each type of human influenza virus. (B) Comparison of the primary sequence of the NS1 protein from various representative human and laboratory-adapted influenza virus strains and viral isolates representing sporadic bird-to-human transmission events. The sequence shown is the one around the two predicted SUMOylation sites in PR8 NS1 (K70 and K219). The predicted consensus SUMOylation sites identified in PR8 NS1 by in silico analyses are depicted underneath the sequence list, with the critical amino acids displayed in boldface type. Note that residue 221 in PR8 NS1 is glutamic acid.