TABLE 2.
Expression of lacZ transcriptional fusions from reporter plasmids in S. flexneri strains
Transcriptional fusion | Reporter plasmida | Size of the cloned fragment (bp) | β-Galactosidase activity in derivatives of the following strainb:
|
Ratioc | |
---|---|---|---|---|---|
Wild type | ipaD | ||||
ipaH7.8-lacZ | pMM11 | 584 | 30 | 1,700 | 55 |
ipaH4.5-lacZ | pMM12 | 625 | 150 | 420 | 3 |
ipaH1.4-lacZ | pMM13 | 568 | 45 | 40 | 1 |
ospC1-lacZ | pMM19 | 740 | 30 | 440 | 15 |
ospF-lacZ | pMM65 | 128 | 45 | 370 | 8 |
ospD3-lacZ | pMM29 | 510 | 130 | 220 | 1.7 |
ospG-lacZ | pMM20 | 338 | 220 | 250 | 1 |
icsB-lacZ | pMM30 | 414 | 1,300 | 760 | 0.6 |
The reporter plasmids were constructed with vector pQF50 (Table 1).
β-Galactosidase activities assayed in derivatives of M90T (wild type) and SF622 (ipaD) are expressed in Miller units and are the means of at least four independent experiments. Standard deviations (not shown) were within 25% of the reported values.
Activity present in the ipaD mutant versus activity present in the wild-type strain.