TABLE 5.
RhaS variants with increased activation at rhaSR
| Activator | Avg β-galactosidase activity (Miller units) in strain:a |
|
|---|---|---|
| Φ(rhaS-lacZ)Δ85 | Φ(rhaS-lacZ)Δ128 | |
| RhaR | 13 | 1,013 |
| RhaS | 7 | 22 |
| RhaS H205R | 160 | 440 |
| RhaS H253Y | 438 | 679 |
a
β-Galactosidase activity was measured from single-copy lacZ fusion strains grown in MOPS-buffered minimal growth medium containing ampicillin and l-rhamnose. The standard errors were less than 10% of the average activities. The strain background was Δ(rhaSR)::kan recA::cat. Wild-type RhaS, wild-type RhaR, or the RhaS variants were expressed from plasmid pHG165 (26) as previously described (17).