Table 3.
Amino acid signatures in different pandemic H1N1 influenza viruses of 1918, 1977 and 2009 at positions conserved for host specificity. Selected proteins and amino acids numbered according to GenBank sequences of different pandemic influenza viruses were compared
| Protein | Position amino acid | H1N1 (1918) | H1N1 (1977) | H1N1 (2009) |
|---|---|---|---|---|
| PB2 | 44 | A | S | A |
| Polymerase PB2 | 199 | S | S | S |
| 271 | T | A | A | |
| 475 | M | M | L | |
| 588 | A | I | T | |
| 613 | V | T | V | |
| 627 | K | K | E | |
| 674 | A | T | A | |
| PB1 | 327 | R | R | R |
| Polymerase PB1 | 336 | V | I | I |
| PB1-F2 | Yes | Yes | No | |
| PA | 28 | L | L | P |
| Polymerase PA | 55 | N | N | D |
| 225 | S | C | S | |
| 268 | L | I | L | |
| 356 | K | R | R | |
| 382 | D | D | D | |
| 404 | A | S | A | |
| 409 | S | N | N | |
| 552 | S | S | T | |
| HA | 237 | V | V | V |
| Hemagglutinin | 389 | I | I | I |
| NP | 16 | D | D | G |
| Nucleocapsid | 33 | I | I | I |
| Protein | 100 | I | V | V |
| 214 | R | K | R | |
| 305 | L | V | F | |
| 357 | K | K | K | |
| 372 | E | D | E | |
| 422 | B | K | R | |
| 442 | T | K | T | |
| 455 | D | E | D | |
| M1 | 115 | V | I | V |
| Matrix protein 1 | 121 | A | A | T |
| 137 | T | A | T | |
| M2 | 11 | T | I | T |
| Matrix protein 2 | 20 | N | N | S |
| 57 | Y | H | Y | |
| 86 | V | A | V | |
| NS2 | 70 | S | G | G |
| Nonstruc. protein 2 | 107 | L | F | L |
Note: Genbank accession numbers: H1N1 (1918), PB2 (DQ208309), PB1 (DQ208310), PA (DQ208311), HA (AF117241), NP (AY744935), M1, M2 (AY130766), NS2 (AF333238); H1N1 (1977), PB2 (DQ508894), PB1 (DQ508895), PA (DQ508896), HA (DQ508897), NP (DQ508898), M1, M2 (DQ508900), NS2 (DQ508901); H1N1 (2009), PB2 (GQ411904), PB1 (GQ411903), PA (GQ411902), HA (GQ411897), NP (GQ411900), M1, M2 (GQ411898), NS2 (GQ411901)