Table 1. Expression of levD promoter:cat fusion as represented by the CAT specific activities in the wild-type strain UA159 and various levQ mutants.
| Strain | CAT specific activity ± SDa on various growth carbohydrates | |||
| Glucose | Fructose | Mannose | Galactose | |
| levQ+ | 2.8±0.4 | 474.0±44.7 | 870.4±85.2 | 9.6±0.6 |
| levQ | 0.1±0.1 | 0.4±0.0 | 0.3±0.3 | 0.1±0.1 |
| levQ con | 29.5±2.0 | 1.7±0.2 | 27.4±1.1 | 590.5±21.2 |
| levQ con/ levR | 0.1±0.2 | 0.0±0.0 | 0.0±0.0 | 0.1±0.1 |
| levQ con/ levT ΔC | 26.0±1.8 | 1.2±0.4 | 8.0±2.4 | 547.8±25.4 |
| levQ con/ levT M1stop | 14.4±0.7 | 0.8±0.4 | 2.7±1.3 | 148.0±40.6 |
| levQ E170A | 3.7±0.9 | 632.9±36.6 | 1,071.0±50.8 | 15.8±5.4 |
| levQ F292S | 57.0±4.0 | 5.2±2.1 | 150.3±4.4 | 555.0±48.1 |
| levQ LS35 | 459.0±30.3 | 251.1±17.2 | 641.4±72.4 | 2,293.5±8.4 |
| levQ LS46 | 183.9±3.2 | 468.3±48.1 | 826.9±34.0 | 1,204.4±16.3 |
a
The data are presented as the average results of three independent cultures. Cells were cultured in TV broth with 0.5% of the indicated carbohydrates and assays were performed as described in Materials and Methods. Activity is expressed as nmol of chloramphenicol acetylated (mg of protein−1×min−1).