TABLE 4.
Effect of ssDNA exonuclease deficiency on SOS expression
| β-Galactosidase activitya |
||||
|---|---|---|---|---|
| Exonuclease deficiency (additional genotype) | Strain no. | No. of experiments | −MMC | +MMC |
| None | N7843 | 10 | 77 ± 8 | 1474 ± 70 |
| ExoI− | N7844 | 7 | 94 ± 4 | 1591 ± 96 |
| ExoVII− | N7859 | 4 | 83 ± 12 | 1343 ± 60 |
| SbcCD− | N7845 | 4 | 65 ± 13 | 1384 ± 61 |
| ExoI− ExoVII− | N7860 | 4 | 136 ± 6 | 1542 ± 95 |
| ExoI− SbcCD− | N7846 | 4 | 102 ± 5 | 1354 ± 82 |
| ExoVII− SbcCD− | N7847 | 4 | 109 ± 7 | 1309 ± 47 |
| ExoI− ExoVII− SbcCD− | N7837 | 7 | 398 ± 28 | 1962 ± 52 |
| None (rpoC[R919H]) | N7888 | 4 | 135 ± 7 | 2520 ± 42 |
| ExoI− ExoVII− SbcCD− (rpoC[R919H]) | N7889 | 4 | 476 ± 40 | 2365 ± 75 |
a
Measured in ΔlacIZYA strains carrying a sulA∷ lacZ+ fusion as described in materials and methods and expressed as Miller Units. Values are means ± SE. MMC = mitomycin C.