FIG. 5.
Organization of mycobacterial dnaG operons. The organization of the macromolecular synthesis operon of E. coli is shown above the dnaG loci of M. smegmatis, M. tuberculosis, and M. leprae. Comparison of the dnaG loci from M. smegmatis, M. tuberculosis, and M. leprae shows that a region of approximately 4,200 bp between the dgt gene and the tRNAAsn gene is highly conserved among these three mycobacterial species. The dnaG genes are shown in dark blue, and the rpsU gene (shown in red) of the macromolecular synthesis operon is replaced by the putative dgt genes, shown in yellow. The sequence upstream of the putative dgt gene in M. leprae shows similarity to the sequences from M. smegmatis and M. tuberculosis; however, an open reading frame has not been assigned to this region in M. leprae. The partial ORF1 of M. smegmatis and that of M. tuberculosis are shown in orange. ORF4 and ORF5 from M. smegmatis and M. tuberculosis do not have homology and are denoted by different colors. The genes coding for the tRNAAsn are shown in light blue.