TABLE 3.
Alanine substitutions in RhaS H-T-H 1 analyzed at wild-type rhaB-lacZ
| RhaS derivative | % of wild-type activitya (sp act [U]) |
|---|---|
| Leu201Ala | 48 (238) |
| Arg202Ala | 4 (14) |
| His205Ala | 28 (97) |
| Arg206Ala | 0.1 (0.7) |
a
β-Galactosidase specific activity was measured from a single-copy rhaB-lacZ fusion in a rhaS deletion strain transformed with plasmids encoding either a wild-type or mutant form of RhaS. Cultures were grown in MOPS growth medium containing glycerol, l-rhamnose, and appropriate antibiotic. The activity of RhaS mutants is represented as the percentage of the activity of wild-type RhaS. Standard errors were less than 10% of the average units.