FIG. 1.

Cd²⁺ uptake by E. coli cells expressing MntA. Cells containing pCL1921 (control), pCL3-5, or pZH3-5 were prepared and preincubated for 10 min at 37°C in ATP medium containing 0.2 μM Cd²⁺. Samples (0.2 ml) were harvested at intervals after 0.1 μM radioactive Cd²⁺ was added. Each point represents the mean ± ranges (n = 2). pCL1921 is a cloning vector; pCL3-5 is pCL1921 containing part of the mntA gene, which encodes 621 amino acids; pZH3-5 is pCL1921 containing the entire mntA gene, which encodes 759 amino acids.