TABLE 1.
Effector profiles of the activation of the Pu promoter by XylR and XylRE172Ka
| Effectorb | β-Galactosidase activity (Miller units)c with regulator:
|
|
|---|---|---|
| XylR (wild type) | XylRE172K | |
| None | 200 | 150 |
| m-MBA | 2,000 | 900 |
| Toluene | 1,980 | 1,000 |
| o-NT | 1,330 | 1,150 |
| m-NT | 130 | 850 |
| p-NT | 1,120 | 800 |
| o-AT | 510 | 350 |
| m-AT | 3,430 | 500 |
| p-AT | 540 | 350 |
a
E. coli ET8000(pRD579) also bearing pTS174 (encoding wild-type XylR) or pAD1 (encoding XylRE172K) was grown as described in Materials and Methods with the indicated aromatics at 1 mM.
b
MBA, methylbenzyl alcohol; NT, nitrotoluene; AT, aminotoluene.
c
Results are averages of at least five independent determinations. Standard deviations were on the order of 10 to 15% of the given values.