TABLE 2.
Effect of site-directed mutations in the −315 palindromic region of the xpsR promoter on expression and regulation
| Plasmid | PxpsR nucleotide sequence fused to lacZ | Mutation | Expressiona from PxpsR in:
|
|
|---|---|---|---|---|
| WT | vsrD | |||
| pRLZ1 | −338 to +36 | None | 5,280 | 443 |
| pRLZ15 | −338 to +36 | −322 CCC→TGG | 775 | 577 |
| pRLZ16 | −338 to +36 | −319 CTAA→Δ | 843 | 575 |
| pRLZ17 | −338 to +36 | −327 AAT→GTA | 4,910 | 709 |
a
Expression (transcription) from PxpsR was monitored by measuring LacZ (β-galactosidase) activity in Miller units as described by Miller (23) in overnight cultures of R. solanacearum wild type (WT) or vsrD mutants (strain AW-D5) carrying pRG970 vectors with PxpsR::lacZ fusions having the indicated mutation. Values are averages from three independent experiments.