TABLE 3.
Transcription activation by partially constitutive variants of RhaS with substitutions that map to RhaS-CTD
| β-Galactosidase Activityc | ||||
|---|---|---|---|---|
| Expt | RhaS varianta | No. of isolatesb | (−) L-rhamnose | (+) L-rhamnose |
| A | Wild type | 0.55 | 218 | |
| F184Y/Q207R | 1 | 8.6 | 8.9 | |
| L201R | 6 | 54 | 329 | |
| L208F | 2 | 5.6 | 285 | |
| Q210R | 1 | 2.6 | 326 | |
| B | Wild type | 0.34 | 206 | |
| F184Y | 0.69 | 218 | ||
| Q207R | 0.73 | 243 | ||
a
Wild type and RhaS variants were encoded on pHG165 transformed into SME3000 (λΦ(rhaB-lacZ)Δ84 Δ(rhaSR)::Km).
b
Number of times this substitution was independently isolated in random mutagenesis screen.
c
Cultures were grown in MOPS growth medium containing glycerol plus ampicillin with or without L-rhamnose as indicated. β-Galactosidase activity (in Miller Units) was assayed. Standard errors were less than 20% of the average units, except for a few of the samples with activities below 3 Miller units. These had errors up to 31% of the average units.