Figure 1. Time course of ¹⁴C-L-proline uptake into H.

pylori P12.

Cells were grown and prepared as described in Experimental Procedures. For the transport assay, 200 µl aliquots of a cell suspension (OD₆₀₀=0.8 in 100 mM Tris/Mes, pH 7.0/150 mM KCl) were prepared per time point. Transport was initiated by simultaneous addition of 50 mM NaCl and 10 µM ¹⁴C-L-proline (26 Ci mol^-1) (final concentrations). After given periods of time at 37°C, transport was terminated by addition of ice cold 100 mM KP_i, pH 6.6/100 mM LiCl and rapid filtration. Radioactivity of bacteria retained on the filters was quantified by liquid scintillation counting. (closed circles) wild type; (open diamonds) HpputP mutant plus pIBHpputP6H; (closed squares) HpputPA mutant; (open triangles) HpputP mutant. The data points represent the average of two parallel measurements. Three repeats of the experiment with independently grown and treated cells yielded similar relationships between H. pylori wild type, mutants and control with activities varying by a factor of up to three between the individual experiments.