TABLE 3.
Activity of the epsI, opsG, and epsR promoters in the presence or absence of EpsR
| Strain | EpsRa | Plasmids | β-Galacto- sidase activity (Miller Ub) | Relative activityc |
|---|---|---|---|---|
| K60 | + | pGepsI::lacZ + pLAFR3 | 337.3 | 1.0 |
| K60 | +++ | pGepsI::lacZ + pKL4 | 50.4 | 0.2 |
| K60 | + | pGL10::lacZ + pLAFR3 | 36.5 | 0.1 |
| K60 | + | pGopsG::lacZ + pLAFR3 | 533.4 | 1.0 |
| K60::epsRΩ | − | pGopsG::lacZ + pLAFR3 | 612.9 | 1.2 |
| K60 | +++ | pGopsG::lacZ + pKL4 | 600.9 | 1.1 |
| K60 | + | pGepsR::lacZ + pLAFR3 | 177.8 | 1.0 |
| K60::epsRΩ | − | pGepsR::lacZ + pLAFR3 | 169.7 | 0.9 |
| K60 | +++ | pGepsR::lacZ + pKL4 | 157.5 | 0.9 |
a
+, produced from one copy of epsR; +++, produced from pKL4; −, not produced.
b
β-Galactosidase activity is expressed in Miller units (micromoles of o-nitrophenyl-β-d-galactopyranoside hydrolyzed per minute per milligram of protein [30]). Values shown are the average of two independent trials.
c
Activity of each promoter in the presence of wild-type levels of EpsR is adjusted to 1.0.