Fig. 1.
Defined iron sources rescue the essentiality of esx-3 region mutants. (A and B) The indicated Mtb strains H37Rv WT, Δesx-3 (mc27788), Δesx-3::esx-3TB (mc27827), ΔesxG (mc27789), ΔesxH (mc27790), Δpe5–ppe4 (mc27792), and ΔmbtB (mc27808) (Fig. S1 and Table S1) were plated on 7H10 medium with or without 100 μM hemin and Tween 80 (0.05%) (Tw 80) (A) or with increasing concentrations of MbJ (B). Some late-appearing contamination was present when Δpe5–ppe4 was plated on medium containing hemin and Tween 80 in A. (C and D) The indicated strains, which differ from those used in the plating experiments shown in A and B in that the sacB-hygR cassettes were removed, were grown in 7H9 medium (C) or 7H9 medium supplemented with 100 μM 2,2′-dipyridyl (D). Data points represent the mean ± SEM from duplicate cultures.