Contribution of CopZ1 and CopZ2 to P. aeruginosa Cu+ tolerance and metal content.
A, growth rate of WT, ΔcopZ1, ΔcopZ2, ΔcopZ1/ΔcopZ2, ΔcopA1, as well as copZ1 and copZ2 complemented strains in the presence of 0–4 mm CuSO4. B, intracellular Cu levels before (ochre) and after (black) 10 min exposure to 0.5 mm CuSO4. Data are the mean ± S.E. of three independent experiments. Significant differences from values in the WT strain as determined by unpaired two-tailed Student's t test are: **, p < 0.01, ***, p < 0.001.