FIG 3.

Iron regulates expression and secretion of EsxG-EsxH in M. smegmatis. (A and B) M. smegmatis was grown in 7H9 or CS medium containing iron or zinc as indicated for 9 h. (A) The relative mRNA levels of mbtI, bfrB, and esxG were normalized to dnaA and are shown as fold changes compared to the sample without iron or zinc. Data represent the means ± the SEM from two experiments with six technical replicates each. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (unpaired Student t test). n.s., not significant. (B) EsxG-EsxH and Ag85 complex proteins were analyzed by Western blotting of cell lysates and CFs.