Table 2.
Activator | Relative β-galactosidase activity
|
|
---|---|---|
rpoD+ | rpoD-RH596 | |
None | 15.0 ± 1.1 | 15.6 ± 1.6 |
cI wild type | (100) | 79.1 ± 4.3 |
cI-pc1 (Gly-43 to Arg) | 4.7 ± 1.1 | 5.4 ± 1.2 |
cI-pc2 (Asp-38 to Asn) | 15.5 ± 0.7 | 133 ± 10 |
cI-pc3 (Glu-34 to Lys) | 0.6 ± 0.1 | 2.0 ± 0.5 |
Strains are derivatives of MS4274 and MS4276 carrying a PRM-lac8 ΔAB prophage plus either no second prophage or one of four Plac-cIA prophages. Four cultures of each strain were grown at 30°C in M9CAA (22), harvested in exponential phase, and assayed as described (23). Specific activities of the four control cultures (rpoD+ cI+) were averaged to yield the mean specific activity of the control (set at 100; corresponds to 131 Miller units). Specific activity of each of the other cultures was expressed as a percentage of the mean specific activity of the control. The four percentages for a particular genotype were used to calculate the mean and standard deviation given.