FIG. 2.

Copper upregulation of copA and copB. (A and B) During growth, strains harboring the copA-lacZ (A) and copB-lacZ (B) fusions were incubated on CTT agar plates containing 0 μM (black lines), 300 μM (blue lines), 600 μM (red lines), or 800 μM (green lines) copper. (C and D) During development, strains harboring the copA-lacZ (C) and copB-lacZ (D) fusions were incubated on CF agar plates containing 0 μM (black lines), 20 μM (blue lines), 40 μM (red lines), or 60 μM (green lines) copper. The specific β-galactosidase activity in cell extracts was determined as described in Materials and Methods. The results are the averages of data from three different experiments. The error bars indicate standard deviations. Note the differences in the scales.