Table 4. NusA-ΔAR2 does not affect termination at timm, a Rho-dependent terminator lacking a nut site.
Strains are MDS42 derivatives that carry the fusion: λpRM - λcI857 – timm – pL – nutL – N::lacZ. At 32°C, pRM is active and pL is repressed; at 42°C, pRM is repressed and pL is active. pRM transcripts terminate at the Rho-dependent timm terminator. Cells were assayed for β-galactosidase activity (Miller units) after overnight growth at 32°C +/− BCM (bicyclomycin, 20μg/ml) or at 42°C. At this concentration, BCM entirely inhibits Rho-dependent termination. Shown is a representative experiment. Assays were performed at least twice with equivalent results.
| strain | nusA | Temp (°C) | BCM | β-gal units |
|---|---|---|---|---|
| 10900 | + | 32 | − | 51 |
| 10900 | + | 32 | + | 378 |
| 10900 | + | 42 | − | 913 |
| 10901 | ΔAR2 | 32 | − | 31 |
| 10901 | ΔAR2 | 32 | + | 625 |
| 10901 | ΔAR2 | 42 | − | 430 |