TABLE 3.
Nalidixic acid and mitomycin C responses in lexA+ and lexA1 host strains
| Fusion to gene or operon | Host straina | Response ratio for:
|
||
|---|---|---|---|---|
| Nalidixic acid (2 h, 10 μg/ml) | Mitomycin C (2 h, 250 ng/ml) | RLU at 2 h, no chemical addedb | ||
| Known LexA regulon members | ||||
| ydjM | lexA+ | 5.2 | 9.0 | 19.58 |
| lexA1 | 0.4 | 0.9 | 12.91 | |
| dinG ybiB | lexA+ | 4.0 | 5.0 | 15.88 |
| lexA1 | 1.0 | 1.1 | 12.96 | |
| Nalidixic acid upregulated on the solid LuxArray and in liquid culturec | ||||
| oraA | lexA+ | 11.1 | 15.3 | 2.69 |
| lexA1 | 1.1 | 1.2 | 2.18 | |
| yigN | lexA+ | 5.7 | 9.8 | 8.08 |
| lexA1 | 0.6 | 0.9 | 5.30 | |
| ycgH | lexA+ | 3.2 | 1.1 | 0.90 |
| lexA1 | 2.3 | 1.7 | 0.64 | |
| intG | lexA+ | 3.2 | 1.2 | 0.08 |
| lexA1 | 1.6 | 2.5 | 0.13 | |
| lpxA lpxB rnhB dnaE | lexA+ | 2.9 | 1.1 | 0.29 |
| lexA1 | 2.4 | 1.3 | 0.29 | |
| rihC | lexA+ | 1.5 | 1.0 | 8.81 |
| lexA1 | 1.2 | 1.0 | 7.28 | |
| Non-DNA damage-responsive control | ||||
| yciG | lexA+ | 0.3 | 0.6 | 0.31 |
| lexA1 | 0.7 | 0.6 | 0.33 | |
a
The lexA+ host strain was E. coli DM800, while the lexA1 host strain was E. coli DM803.
b
The light production in the absence of perturbation reflects the relative basal levels of promoter activity. RLU, relative light units.
c
Fusions to oraA and yigN were LexA dependent and generally DNA damage responsive, while those to ycgH, intG, the lpxA lpxB rnhB dnaE operon, and rihC were nalidixic acid upregulated and not generally DNA damage inducible.