TABLE 1.
An hfq-1 mutation decreased the regulatory activity of DsrA RNA
| Reporter fusiona | Other allelesb | β-Galactosidase sp act (U)c
|
Colony phenotyped | |
|---|---|---|---|---|
| Vector | pDsrA | |||
| RpoS::LacZ | Wild-type | 50 | 610 | Mucoid |
| dsrA1 | 11 | 600 | Nonmucoid | |
| hfq-1 | 2.5 | 20 | Nonmucoid | |
| hfq-2 | 48 | 593 | Mucoid | |
| rcsA90::lacZ | Wild-type | 15 | 103 | Mucoid |
| hfq-1 | 10 | 12 | Nonmucoid | |
| hfq-2 | 14 | 90 | Mucoid | |
| cps-2::lacZ | Wild-type | 12 | 90 | Mucoid |
| hfq-1 | 10 | 15 | Nonmucoid | |
All strains are single-copy λ(imm21) lysogens at att λ. Strains were grown in LB medium at 30°C. The RpoS::LacZ fusion is a translational fusion. The cps-2 and rcsA90::lacZ fusions are transcriptional fusions.
Mutations were transduced into the fusion strains by P1-mediated transduction.
Total β-galactosidase units were plotted against the OD600 of the culture. The slope of the curve between OD values of 0.2 and 1.0 (approximately log phase) was used as the specific activity of each fusion. Slopes had an r2 of >0.95. Specific activities varied less than 10% between experiments.
Colony phenotypes for strains with pDsrA were determined after growth overnight on LB plates at 30°C. vector (pACYC184) or pDsrA (dsrA cloned into pACYC184) (26) were used.