FIG. 6.

Activation (A to C) and inactivation kinetics (D) of KdpD, KdpD-C, and C499-894 in HMK006. HMK006 cells expressing KdpD (A), KdpD-C (B), or C499-894 (C) were grown overnight in minimal medium containing 10 mM KCl. Cells were washed with minimal medium containing 0.1 mM KCl and diluted 1:100 into fresh minimal medium containing 0.1 mM KCl. A control culture was resuspended in medium containing 10 mM KCl. The β-galactosidase activity was determined at the indicated time points and normalized to the maximum β-galactosidase activity (100% of control Miller units) of the KdpD⁺ culture growing in medium containing 0.1 mM KCl. (D) HMK006 cells expressing KdpD, KdpD-C, or C499-894 were grown in minimal medium containing 0.1 mM KCl to mid-logarithmic phase. Then, 10 mM KCl was added. Samples were taken at the indicated time points after addition of 10 mM KCl and assayed for β-galactosidase activity.