FIGURE 1.

Growth response of mycobacterial P_1B4-ATPase mutant strains to iron, hemin, and streptonigrin/iron. A and B, M. smegmatis WT (●; black) and ΔctpJ (▾; blue) and complemented (▿; blue) strains were grown in the presence of increasing concentrations of FeCl₃ (A) or hemin (B) in the LIMM for 16 h, and A₆₀₀ was measured. C, M. smegmatis WT (gray bars), ΔctpJ (blue bars), and complemented (white bars) strains were grown in LIMM supplemented with 1 μg ml⁻¹ STN and 10 μm FeCl₃, and growth was measured at 16 h. D and E, M. tuberculosis WT (●; black), ΔctpD (■; blue) and complemented (□; blue), ΔctpJ (▴; green) and complemented (▵; green), and ΔctpD:ΔctpJ (♦; red) strains were grown in the presence of increasing concentrations of FeCl₃ (D) or hemin (E) in LIMM for 5 days, and A₆₀₀ was measured. F, M. tuberculosis WT (gray bars), ΔctpD (green bars), ΔctpD complemented (white bars), ΔctpJ (blue bars), ΔctpJ complemented (white bars), and ΔctpD:ΔctpJ (red bars) strains were grown in LIMM supplemented with 1 μg ml⁻¹ STN and 10 μm FeCl₃, growth was measured at 5 days, and A₆₀₀ was measured. Data are the mean ± S.E. (error bars) of three independent experiments. Significant differences from the WT as determined by Student's t test are indicated (*, p < 0.05).