TABLE 5.
Effect of glpFKX amplification on ompF, ompC, ompA, and lacZ expression
| Fusion or gene (in MC4100) tested | Plasmid introduced | β-Galactosidase activitya | Repression by glpb |
|---|---|---|---|
| Φ(ompF′-lacZ+)7.14 | pACYC177 | 372 ± 82 | |
| pGPH9925 (glpFKX) | 191 ± 20 | 2 | |
| Φ(ompC′-lacZ+)10.21 | pACYC177 | 160 ± 42 | |
| pGPH9925 (glpFKX) | 209 ± 30 | 0.8 | |
| Φ(ompA′-lacZ+) (Hyb) | pACYC177 | 81 ± 4 | |
| pCJ102 (glpK) | 76 ± 18 | 1 | |
| lacZ | pACYC177 | 4,520 ± 400c | |
| pGPH9925 (glpFKX) | 2,497 ± 71c | 1.8 |
a
β-Galactosidase activity was assayed during growth at 30°C in MM adjusted to pH 7 and supplemented with glycerol and appropriate antibiotics.
b
Repression values correspond to the ratio of β-galactosidase activities produced by the indicated operon fusion without glp amplification to the activities produced with glp amplification.
c
1 mM IPTG was added to the medium.