FIG 3.

The TtsS/TtsR two-component system positively regulates cbpE and txc gene expressions. Shown are β-galactosidase activities of Ptxc-lacZ (a) and PcbpE-lacZ (b) transcriptional fusions (in Miller units) in PA7::Ptxc-lacZ (Ptxc-lacZ) and PA7::PcbpE-lacZ (PcbpE-lacZ) strains overproducing TtsS_c or TtsR_c or not (pBBR). β-Galactosidase activities were also measured in the strain bearing the promoterless lacZ fusion, PA7::lacZ (lacZ), as a negative control. The growth curves of the strains are also shown (OD₆₀₀). The experiment was reproduced three times. Samples were duplicated for each experiment, and the corresponding standard deviations were calculated.