FIG. 7.

Growth-dependent dilution of the KdpA-PhoA, Kup-PhoA, and TrkH-PhoA proteins. (a) Cultures of various transformants of ftsE(Ts) and ftsE⁺ by the plasmid encoding KdpA-PhoA, Kup-PhoA, or TrkH-PhoA were grown exponentially at 30°C in K10 medium containing 50 μM IPTG (open arrow) and diluted 1- to 200-fold with the same medium, followed by further incubation at 41°C (solid arrow). At each time point (small arrows), OD₆₀₀, the number of cells, and the amounts of PhoA fusion proteins were measured. (b) The OD₆₀₀ values of each sample, 0.17 to 0.4, were corrected for the dilution factors and are shown relative to the value of the 0-h sample. Cell numbers (▴) were measured by a Coulter counter. The proteins (10 μg each) of the membrane fractions were analyzed by Western blotting, and the relative amounts of the PhoA fusion proteins were plotted against the relative increase in OD₆₀₀. •, ftsE(Ts) transformants; ▪, ftsE⁺ transformants.