TABLE 2.
Activation of inaA::lacZ in tolC mutantsa
| Strain
|
Activator controlled by lac promoter | No treatment with 2,2′-dipyridyl
|
Treatment with 5 mM 2,2′-dipyridyl
|
|||||
|---|---|---|---|---|---|---|---|---|
| β-Galactosidase activity (MU)
|
Ratiob | β-Galactosidase activity (MU)
|
Ratiob | |||||
| tolC+ | tolC | tolC+ strain | tolC strain | tolC+ strain | tolC strain | |||
| M4110 | M4114 | None | 6.1 (0.42)c | 11 (1.6) | 1.8 | 12 (0.6) | 16 (1.8) | 1.3 |
| M4111 | M4115 | MarA | 85 (15) | 84 (17) | 1.0 | 63 (17) | 53 (7.4) | 0.84 |
| M4112 | M4116 | SoxS | 80 (24) | 81 (20) | 1.0 | 72 (18) | 61 (9.2) | 0.85 |
| M4113 | M4117 | Rob | 42 (10) | 209 (58) | 5.0 | 675 (139) | 919 (154) | 1.4 |
a
Strains were grown in LB broth at 32°C to an A600 of 0.1, diluted twofold into LB broth with or without 2,2′-dipyridyl, and aerated for 1 h at 32°C. Cells were placed on ice, and an assay was performed to determine the β-galactosidase activity, which was expressed in Miller units (MU). All strains have chromosomal lacIZYA, marRAB, soxS, and rob null mutations.
b
Ratio of the activity in the tolC mutant to the activity in the tolC+ strain.
c
The standard errors of the means are indicated in parentheses.