Table 2. The effect of virS mutations on perfringolysin O production.
| Strain | Base Changeb/Characteristic | Amino Acid Change | PFO titre (log)2 a |
| Random Mutants | |||
| JIR4000(pJIR751) | vector control | <1 | |
| JIR4000(pJIR884) | virS+ positive control | 5.8±0.1 | |
| JIR4000(pJIR2108)* | CTT → TTT | L99F | <1 |
| JIR4000(pJIR1983) | ACA → GCA | T100A | <1 |
| JIR4000(pJIR2105)* | GAA → AAA | E102K | <1 |
| JIR4000(pJIR1977) | CAT → TAT | H255Y | <1 |
| JIR4000(pJIR1930) | GAT → GGT | D256G | <1 |
| JIR4000(pJIR2028) | AAT → AAA | N259K | <1 |
| JIR4000(pJIR2106)* | CAC → TAC | H260Y | <1 |
| JIR4000(pJIR2073) | TGT → TAT | C335Y | <1 |
| JIR4000(pJIR1953) | GGC → GAC | G402D | <1 |
| JIR4000(pJIR2186)* | GGA → AGA | G415R | <1 |
| Site-Directed Mutants | |||
| JIR4000(pJIR2306) | ATT → TTT | I88F | 4.6±0.1 |
| JIR4000(pJIR2305) | TTA → TTT | L92F | 3.7±0.1 |
| JIR4000(pJIR2326) | TTA → GCA | L96A | 5.7±0.1 |
| JIR4000(pJIR2325) | TTA → AAT | L96N | 5.7±0.1 |
| JIR4000(pJIR2206) | TTA → TTT | L96F | <1 |
| JIR4000(pJIR2379) | CTT → AAT | L99N | <1 |
| JIR4000(pJIR2378) | CTT → GCA | L99A | <1 |
| JIR4000(pJIR2175) | ACA → TCA | T100S | 5.0±0.5 |
| JIR4000(pJIR2173) | ACA → TGT | T100C | 2.0±0.4 |
| JIR4000(pJIR2177) | ACA → GTA | T100V | <1 |
| JIR4000(pJIR2231) | CTA → TTT | L104F | 4.6±0.3 |
a
PFO titre±SD: Perfringolysin O activity is shown as the average of duplicate assays carried out on preparations from at least three separate cultures of each strain.
b
Base changes are shown in bold.
*
refers to hydroxylamine derived mutants.