TABLE 1.
Complementation of cya in E. coli DHP1 using sigE and sigD fusions to B. pertussis cya domains
| Test plasmid pair | Mean β-galactosidase activity (Miller units) ± SDa |
|---|---|
| pT18 + pT25 (vectors) | 81 ± 2 |
| pT18 + pT25-SigD′ | 55 ± 2 |
| pSigD′-T18 + pT25 | 61 ± 0 |
| pSigE-T18 + pT25 | 61 ± 5 |
| pSigE-T18 + pT25-SigE | 2,405 ± 220 |
| pSigE-T18 + pT25-SicA | 62 ± 5 |
| pSigD′-T18 + pT25-SigE | 439 ± 43 |
| pSigD′-T18 + pT25-SicA | 68 ± 4 |
| pSigE-T18 + pT25-SigD′ | 93 ± 3 |
a
E. coli strain DHP1 containing the indicated plasmids was grown overnight (18 h) in Luria-Bertani broth supplemented with chloramphenicol (25 μg/ml) and ampicillin (100 μg/ml) in 13-cm test tubes at 26°C on a roller drum. β-Galactosidase activity was measured as described in the text.