FIGURE 3.

Binding of wild-type and mutant Cma proteins to the FhuA receptor in a competition assay with albomycin. Exponentially growing E. coli Mo3 fkpA40 in LB medium untreated (■) and treated with 1 μg ml⁻¹ albomycin (▴), treated with 0.1 mg ml⁻¹ wild-type Cma and albomycin (□), with mutant Cma(P107A) and albomycin (♢), with mutant Cma(P129A) and albomycin (●), with mutant Cma(P176A) and albomycin (○), and with mutant Cma(P260A) and albomycin (▵). Growth was monitored spectrophotometrically. The arrows indicate the addition of the Cma samples and albomycin.