FIG 1.
Structure of promoters recognized by σ70 factors. The general structure of promoters recognized by the three well-studied representatives of the σ70 protein family—E. coli RpoD, E. coli σE, and B. subtilis σW—is shown. The indicated promoter elements correspond to the following consensus sequences: the −35 element and −15 element (9), which interact with the σ factor in the dsDNA form, and the short −10 element, which is involved in ssDNA interactions. The −15 element consensus is commonly shown as −15TGnT−12 in E. coli RpoD but is here shown as −15TGGT−12, since in reference 13, it was demonstrated that −13G is significantly conserved (more than −15T).