Figure 1.

Conservation of M. tuberculosis H37Rv two-component signal transduction systems. Homologs of these genes in other mycobacterial species were: +, present with conserved genetic arrangement; ✻, present with differences in genetic arrangement; or −, absent from the genomes of M. avium (Ma), M. bovis (Mb), M. leprae (Ml), M. smegmatis (Ms), and M. tuberculosis CSU#91 (Mt). When indicated (●), promoter fragments from response regulators were fused to the promoterless gfp gene. Note that not all response regulator promoters could be fused to gfp because of paired arrangements with sensor kinase genes.