FIG 2.

Conservation of M. tuberculosis regulatory factors and the stresses that the factors are associated with in M. tuberculosis (160–184). The left side of the table designates whether the gene for a transcriptional regulator is essential (shaded) or not essential (N) in M. tuberculosis (Mtb) and whether that gene is conserved (shaded) or not conserved (X) or exists as a pseudogene (P) in the environmental saprophytic M. smegmatis (Msmeg) or the obligate pathogen M. leprae (Mlep). The right side of the table indicates whether a particular stress condition has been associated with a given transcriptional regulator. Involvement in the response to a particular stress is designated by shading of the box and may represent expression profiling data or phenotypic analysis of mutants. An unshaded square indicates that the factor is not induced, is not important for survival, or has not been studied under that particular condition. U, unnamed factor; *, starvation (including nutrient, phosphate, and nitrogen starvation); **, iron-depleted or iron-replete conditions. See specific references for more information.