Figure 6. Effect of the OmpR protein on ompX promoter activity in Y. enterocolitica O:9 strains.

The expression of ompX was measured by the activity of transcriptional reporter ompX-lacZ fusions. The strains Ye13, AR9 and AR9 with plasmid pBR3 expressing OmpR, were grown at temperatures of 25 or 37°C in LB medium and β-galactosidase activity was assayed to evaluate expression. Values represent the mean β-galactosidase activities expressed in Miller units ± SD from three independent experiments. Different letters (a, b) above the columns indicate statistically significant differences (p<0.05, covariance with Tukey correction).