TABLE 3.
Transcriptional activities of derivatives of the pyxaAB promoter in different genetic backgroundsa
| Plasmid | Description | Mean β-galactosidase activity (nmol of produced ONP mg−1 min−1) ± SDb in:
|
|
|---|---|---|---|
| Wild type | ΔabrB mutant | ||
| pKN1 | yxaAB gene promoter with all surrounding sequences | 0.8 ± 0.3 | 3.1 ± 0.8 |
| pKN1-1 | yxaAB gene promoter with all surrounding sequences; gnt operon promoter inactivated by deletion of −10 region | 1.6 ± 0.3 | 5.1 ± 1.1 |
| pKN1-2 | yxaAB gene promoter with predicted UP | 4.4 ± 0.9 | 10.1 ± 1.8 |
| pKN1-3 | yxaAB gene promoter with shortened predicted UP | 6.1 ± 1.1 | 12.1 ± 1.7 |
| pKN1-4 | Core of yxaAB gene promoter | 8.2 ± 1.5 | 17.8 ± 3.2 |
a
For details concerning the pyxaAB derivatives, see Fig. 3 and the text.
b
Data were collected at the transition stage of growth from three independent experiments.