Table 3. NusA-ΔAR2 dominant transcription termination defects at λnutRtR1.
Strains are derivatives of MDS42 and where indicated, carry a plac-NusA+ plasmid. lacZ is expressed from the fusion λcI857 – pR – cro (ΔRBS) – nutR – tR1 – cII::lacZ. Cells are assayed for β-galactosidase activity (Miller units) after overnight growth at 42°C. Strains carrying plasmids were induced with IPTG (0.5 mM). Shown is a representative experiment. Assays were performed at least twice with equivalent results.
| strain | nusA | plasmid | β-gal units |
|---|---|---|---|
| 10323 | + | − | 176 |
| 10324 | Δ | − | 343 |
| 10881 | ΔAR2 | − | 902 |
| 10875 | + | plac-NusA | 227 |
| 10876 | Δ | plac-NusA | 158 |
| 10889 | ΔAR2 | plac-NusA | 1114 |