| L68Q | Non-neutral | 4 | 82 |
| L68R | Non-neutral | 5 | 87 |
| L68K | Non-neutral | 5 | 87 |
| D69R | Non-neutral | 1 | 63 |
| D69Q | Neutral | 0 | 53 |
| D69T | Non-neutral | 1 | 63 |
| T72N | Neutral | 0 | 53 |
| T72P | Non-neutral | 1 | 63 |
| T72G | Neutral | 0 | 53 |