FIGURE 2.

Characteristics of high iron-resistant Δccc1 mutants. A, DY150, DY150 Δccc1, R1 mutant, DY1457, DY1457 Δccc1 and W2, W7, and W17 mutants were grown in CM medium overnight. 20 OD cells (2 × 10⁸) were collected, washed, and digested in nitric acid and iron contents were determined by ICP. B, strains were streaked onto CM plates containing 40 μm BPS with 2 and 10 μm FeSO₄ added back. Plates were incubated at 30 °C for 2 days. 1, Δfet3; 2, DY150; 3, DY150Δccc1; 4, R1 mutant; 5, Δfet3; 6, DY1457; 7, DY1457Δccc1; 8, W2; 9, W7; 10, W17. C, cells as in A were grown in CM medium, spotted onto CM or CM with 0.005% H₂O₂ or 2.5 mm paraquat. Plates were incubated at 30 °C for 2 days. D, cells as in A were transformed with a reporter construct CCC1-lacZ and either a control vector (V) or alow copy CCC1 plasmid. The cells were grown in CM-Leu-Ura medium to log phase, harvested, and β-galactosidase activity determined. The data were normalized for protein concentration and error bars represent S.D. from three experiments.