Figure 3

The influence of salt and temperature on the VipA-VipB interaction. The VipA-VipB interaction in the reporter strain KDZif1ΔZ leads to β-galactosidase activity, which is influenced by the growth temperature as well as the NaCl concentration of the medium. Shown is the mean β-galactosidase activity ± standard deviation in Miller units produced from two experiments where two independent transformants were tested on each occasion. The temperatures tested were 37°C (High) or 23°C (Low). Data was subjected to a student’s 2-sided t-test to determine whether the β-galactosidase activity produced at any given condition was significantly different from that produced by KDZif1ΔZ grown under standard assay conditions (85 mM NaCl, 37°C) (*, P < 0.05; **, P < 0.01; ***, P < 0.001).