Table 4.
Amino acid variations in natural isolates
| Amino acid position | Changed amino acids | Surface (S) or inside (I) |
|---|---|---|
| 20 | A, I, T | S |
| 22 | N, S, T | S |
| 45 | D, G, N | S |
| 48 | H, P, R | S |
| 53 | D, K, N | S |
| 69 | I, P, Q | S |
| 94 | I, N, T | S |
| 103 | A, L, S, T | I |
| 131a | K, R, S | S |
| 135b | D, G, N | S |
| 146 | E, H, K, Q | S |
| 148a | D, N, S | S |
| 150 | A, D, S, T | S |
| 153 | I, T, V | S |
| 164 | E, K, R | S |
| 179b | A, N, T | S |
| 180 | A, E, G, T, V | S |
| 182a | D, E, N | S |
| 200 | D, N, T | S |
| 206 | L, M, S, V | S |
| 216b | L, M, Q | S |
| 264 | H, K, N, T, Y | S |
| 265 | G, K, N, R, S | S |
| 267 | D, N, S | S |
| 269 | A, T, V | I |
| 316 | A, S, T | Cleavage site |
| 317 | G, K, R | Cleavage site |
| 318 | A, L, S | Cleavage site |
Amino acid comparison was performed with 133 viruses clustered with Y280 lineage, isolated from 1994 to 2005. Positions were selected in which three or more amino acids were different. Escape mutant has a change in this residue in this study (a) and in that of Kaverin et al. (b) [12]