MtrA footprinting analysis in the M. tuberculosis dnaA promoter region. (A) DNase I footprinting assay of the protection of two short dnaA promoter regions (S6 and S7) against DNase I digestion by MtrA. The substrate S6 contains S1 and S2 sequences, and the substrate S7 contains S5 sequences. The ladders are shown in the right panel and the obtained nucleotide sequences are listed. The protected regions are indicated. The two specific sequence boxes are indicated by "*". (B) Summary of MtrA footprinting analysis in the M. tuberculosis dnaA promoter region. The DNA sequence correspond with the dnaA promoter region from -303 to -1. The position of two transcription start sites (P1dnaA and P2dnaA), two footprint regions, and two MtrA binding boxes are indicated.