TABLE 2.
Effects of point mutations on J/C-NS3proH77-Ubi viral production
| Backbone | Amino acid substitution ina: |
Mean infectious titer ± SD (log TCID50/ml)b | ||
|---|---|---|---|---|
| Ubi | NS3JFH1 protease | NS3JFH1 helicase | ||
| JFH1 | — | — | — | 3.29 ± 0.40 |
| J/C-NS3proH77-Ubi | — | — | — | < |
| I44T | — | — | < | |
| — | — | Q1251L | 2.94 ± 0.49 | |
| — | P1032L | — | 3.47 ± 0.63 | |
| — | P1032L | Q1251L | 2.79 ± 0.62 | |
| — | P1159Q | — | 3.02 ± 0.48 | |
a
A substitution introduced by site-directed mutagenesis into the J/C-NS3proH77-Ubi cDNA within the sequence encoding the indicated protein is denoted by the native residue followed by its numbering within JFH1 polyprotein and the mutant residue (except for the substitution in the ubiquitin gene, which is numbered according to the amino acid position within the Ubi gene). —, none.
b
Infectious titers (mean results ± standard deviations from 3 transfection experiments, each with 2 or 3 independently transcribed RNAs) were determined 3 days posttransfection. <, below infectivity threshold (1.60 log TCID50/ml).