TABLE 4.
Genetic analysis of malT and malK repression by glpFKX amplification
| Fusiona tested and genetic background | Plasmid introduced | β-Galactosidase activityb | Repression by glpc |
|---|---|---|---|
| Φ(malK′ -lacZ+)1 | |||
| MC4100 | pACYC177 | 339 ± 51 | |
| pGPH9925 (glpFKX) | VL | Full | |
| GPH8818 (malTp1 malTp10) | pACYC177 | 377 ± 77 | |
| pGPH9925 (glpFKX) | 220 ± 57 | 1.7 | |
| GPH8549 (cya crp∗) | pACYC177 | 122 ± 10 | |
| pGPH9925 (glpFKX) | 60 ± 11 | 2 | |
| Φ(malT′-lacZ+)1 | |||
| MC4100 | pACYC177 | 593 ± 41 | |
| pGPH9925 (glpFKX) | 194 ± 25 | 3 | |
| GPH8549 (cya crp∗) | pACYC177 | 404 ± 95 | |
| pGPH9925 (glpFKX) | 345 ± 71 | 1.2 | |
| Φ(malTpl malTp10′- lacZ+)1, MC4100 | pACYC177 | 720 ± 137 | |
| pGPH9925 (glpFKX) | 1,145 ± 250 | 0.6 |
a
The indicated operon fusion on pJEL250.
b
β-Galactosidase activity was assayed during growth at 30°C in MM adjusted to pH 7 and supplemented with glycerol, ampicillin, and kanamycin. VL, very low β-galactosidase activity (below the sensitivity threshold of the method used).
c
Repression values correspond to the ratio between β-galactosidase activities of the indicated fusion in the presence of pGPH9925 and in the presence of pACYC177.