FIG. 5.

Effect of preB mutations on the expression of pmrA regulon promoters. Salmonella strains were grown in LB medium, and β-galactosidase assays were performed as described in Materials and Methods. Activities are expressed in Miller units. Error bars indicate the standard deviations. Data are from a representative experiment with two replicates. The following strains were used: JSG1051 (pmrHFI-lacZ), JSG1058 (preB pmrI-lacZ), JSG214 (pmrE-lacZ), JSG1040 (preB pmrE-lacZ), JSG1525 (yibD-lacZ), JSG1527 (preB yibD-lacZ), JSG2527 (ΔpreB pmrA yibD::lacZ), JSG2420 (ΔpreA yibD-lacZ), and JSG2523 (ΔpreA pmrA yibD-lacZ).