| Figure 9-2.2 |
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| Structure of bacterial consensus promoters and regions of sigma subunits that contact DNA | |
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| (a) The four major regions of sigma conservation are indicated on the diagram of a sigma factor. Regions of contact between the sigma factor and the promoter are indicated by arrows. (b) The consensus sequences for promoters recognized by the major E. coli and B. subtilis sigma factors and the E. coli σH, σN and σF alternative sigma factors. N = any nucleotide, W = A or T. Sigma factors are referred to either by a letter designation or by the molecular weight in kilodaltons. |