Fig. 9: Deletion and mutations of the KtrB N-terminus affect K+ uptake by the KtrAB complex.

a, b Vmax (a) and KM (b) for KtrB IDR variants. Uptake experiments were performed as described above. E. coli LB2003 cells produced KtrAB WT and variants thereof, as well as KtrB in the absence of KtrA. K+-depleted cells were prepared, and K+ uptake was measured in the presence of 0.1, 0.2, 0.4, and 1 mM KCl. All measurements were performed several times as indicated in the figure (n = x) and the Michaelis-Menten kinetics were determined using initial uptake velocities. Data are presented as a scatter plot graph with gray bars representing mean values +/− SDs. Exemplary uptake data are shown in Supplementary Fig. 11.