FIG 2.

CopA and CadA are not involved in AgNO₃ response. (A) Wild-type (WT) and copA mutant (copA⁻) cells were grown in microplates under microaerobic conditions. Indicated concentrations of AgNO₃ were added to the growth medium after 8.5 h, when cells reached an OD₆₈₀ of 0.3 (arrow). (B) Growth phenotype of the WT, copA and ΔcadA mutants in the presence of indicated concentrations of AgNO₃, CuSO₄, or CdCl₂ on solid malate media. Cells were grown aerobically for 24 h at 30°C prior to photography. (C) Induction of CopA-H₆ and CopI expression in cells shocked for 1 h with 0.5 mM CuSO₄, 0.5 mM CdCl₂, or 1 to 10 µM AgNO₃. Cells were grown in photosynthetic condition and metals were added to the growth medium when cells reached an OD₆₈₀ of 0.8. Total protein extracts from the same amount of cells (OD₆₈₀ of 0.1) were separated on 14% SDS-PAGE. The proteins were revealed on a Western blot using an HisProbe-HRP.