FIG. 4.

Co²⁺ and Mn²⁺ inhibition of transport. Co²⁺ and Mn²⁺ inhibitions of ⁶³Ni²⁺ uptake were measured as previously described (3, 15). The data shown are normalized to the maximal uptake of each CorA. A single experiment with each cation (with triplicates at each concentration) was performed and was repeated once with similar results. The Ni²⁺ concentration used was 100 μM. Uptake by the ST-CorA was 0.85 nmol of ⁶³Ni²⁺ min⁻¹ unit of optical density at 600 nm (OD₆₀₀)⁻¹; uptake by the MJ-CorA was 0.09 nmol of ⁶³Ni²⁺ min⁻¹ unit of OD₆₀₀⁻¹.