Figure 4.

Activation of the aatP promoter from EAEC strains 042, E36 and E42. The figure illustrates measured β-galactosidase activities in E. coli K-12 BW25113 ∆lac cells, containing pRW50 carrying aatP100 promoter fragments from EAEC strains 042, E36 and E42. Cells also carried either pBAD/aggR (gray bars) or pBAD24 (black bars), and were grown in LB medium with (+) or without (-) 0.2% arabinose. β-galactosidase activities are expressed as nmol of ONPG hydrolyzed min⁻¹ mg⁻¹ dry cell mass. Each activity is the average of three independent determinations and standard deviations are shown for all data points