TABLE 2.
Activation of the Pu promoter by XylR, XylRD135N, XylRD135E, and XylRD135Qa
| Effectorb | β-Galactosidase activity (Miller units)c with:
|
|||
|---|---|---|---|---|
| XylR (wild type) | XylRD135Q | XylRD135N | XylRD135E | |
| None | 200 | 1,230 | 2,160 | 90 |
| m-MBA | 2,000 | 2,520 | 2,400 | 230 |
| Toluene | 1,980 | 2,140 | 2,590 | 240 |
| o-NT | 1,330 | 3,190 | 2,460 | 100 |
| m-NT | 130 | 1,130 | 1,060 | 20 |
| p-NT | 1,120 | 2,240 | 1,630 | 40 |
a
E. coli ET8000(pRD579) also bearing pTS174 (encoding wild-type XylR), pAD49 (encoding XylRD135N), pRS1 (encoding XylRD135E), or pRS2 (encoding XylRD135Q) was grown as described in Materials and Methods with the indicated aromatics at 1 mM.
b
MBA, methylbenzyl alcohol; NT, nitrotoluene.
c
Results are averages of at least five independent determinations. Standard deviations were on the order of 10 to 15% of the given values.