TABLE 4.
E2 and E1 changes during independent passage series
| Passage seriesa | E2 changes (residues 225–270) | E1 changes (residues 375–416) |
|---|---|---|
| 1 | Asp-248→Tyr | Gln-411→Leu |
| 2 | Leu-243→Ser | None |
| 3 | Val-237→Phe | None |
| 4 | None | Gln-411→Leu |
| 5 | None | Phe-399→Ser |
| 6 | Asp-248→Ala | None |
| 7 | Asp-242→Gly | None |
| 8 | None | None |
| 9 | None | None |
| 10 | None | None |
| 11 | None | None |
a
Eleven independent passage series were initiated with the chimera SIN(RRE1) as described in the Materials and Methods, and virus from P10 of each series was sequenced in the E1 and E2 regions. For series 1, all of E1 and E2 were sequenced, and only one change was found in each of E1 and E2; for series 2 to 11, only small regions around the changes found in series 1 were sequenced (225 to 270 in E2 and 375 to 416 in E1). The passage series numbers within series 2 to 5 and within series 6 to 11 have been changed for presentation in order to group similar results together.