TABLE 3.
Role of Lrp in the regulation of various operons of the Ntr regulon
| Straina | Relevant genotype | Sp act (U/mg of protein) ofb:
|
||
|---|---|---|---|---|
| Glutamate synthase | Glutamate dehydrogenase | Histidase | ||
| KC3346 | Wild type | 117 ± 11 | 427 ± 66 | 41 ± 4 |
| KC4602 | lrp-101 | ≤15 ± 0.3 | 225 ± 23 | 53 ± 6 |
a
The growth medium was comprised of W4 salts (4) supplemented with glucose (0.4%), ammonium sulfate, l-glutamine (0.2%), l-leucine, l-isoleucine, l-valine, and l-serine (0.005%). KC4602 also contained ampicillin at 100 μg/ml to maintain the lrp-101 allele.
b
Means ± standard errors of the means of at least three independent experiments. The assays were performed as described previously (18).