TABLE 1.
Effect of spermidine on the β-galactosidase activity of lacZ fusions to pucB, pufB, and the RSP3361 genec
| lacZ fusiona | Vectorb | Spermidine
|
|
|---|---|---|---|
| Absent | Present | ||
| Φ(pucB-lacZ) | pCF200 | 272.4 | 517.5 |
| Φ(pufB-lacZ) | pUI1663 | 398.3 | 506.5 |
| Φ(pufB-lacZ) | pUI1662 | 36.4 | 62.0 |
| Φ(RSP3361-lacZ) | pJE4935 | 9.8 | 24.6 |
| Φ(RSP3361Δ1-lacZ) | pJE4936 | 2.6 | 6.8 |
| rrnB(div.)-Φ(pucB-lacZ) | pJE5400 | 71.3 | 177.7 |
| rrnBPdown(div.)-Φ(pucB-lacZ) | pJE5403 | 24.5 | 51.9 |
a
“(div.)” indicates that the rrnB promoters are divergently transcribed from pucB. Δ1 indicates a deletion of PrrA site 1.
b
The lacZ fusion vectors used were constructed as described in the following references: pCF200 (50); pUI1663 and pUI1662 (25); pJE4935 and pJE4936 (29); pJE5400 and pJE5403 (this study). All fusions are transcriptional, except for that of pUI1662, which is a translational fusion to pufB.
c
Cells were grown aerobically by sparging with 69% N2, 30% O2, and 1% CO2. Units of β-galactosidase are expressed in μmol/min/mg protein. Experiments were performed in duplicate, and the standard deviation was ≤15%.