TABLE 4.
Role of GltC in ornithine-mediated gltA repressiona
| Strain | Relevant genotype | gltA/gltC region of the fusion | β-Galactosidase activity (gltA-lacZ fusion) (U)
|
|||
|---|---|---|---|---|---|---|
| Medium with glucose plus:
|
Medium without glucose but with ornithine | |||||
| Ammonium | Glutamate | Ornithine | ||||
| LG219 | Wild type | gltAp+ | 74.2 | 2.0 | 1.1 | 0.8 |
| BB917 | gltC(P88L) | gltAp+ | 100.5 | 13.5 | 26.2 | 75.6 |
| BB1051 | gltC(P88L) tnrA | gltAp+ | 104.7 | 125.8 | 76.0 | |
| BB947 | gltC(T99A) | gltAp+ | 167.6 | 27.9 | 29.1 | 208.8 |
| BB1052 | gltC(T99A) tnrA | gltAp+ | 203.5 | 203.5 | 222.8 | 208.3 |
| BB977 | gltC(I160K) | gltAp+ | 104.6 | 5.8 | 8.0 | 61.0 |
| BB1053 | gltC(I160K) tnrA | gltAp+ | 124.1 | 99.0 | 52.6 | |
| LG286 | Wild type | gltAp86 | 166.5 | 21.3 | 56.9 | 198.5 |
| LG286-T | tnrA | gltAp86 | 192.0 | 191.0 | 126.0 | 195.8 |
a
Strains BB917, BB947, BB977, and BB1051 to BB1053 contain a gltA-lacZ fusion as in LG219 and the proJ::pBB559 (′proJ′ neo) insertion linked to the gltC locus. The strains were grown to mid-exponential phase in the indicated minimal media and assayed for β-galactosidase activity.