FIG 2.

Alignment of −10 elements in promoters recognized by σ⁷⁰ factors. Shown is an alignment of the sequence logos for −10 elements recognized by bacterial ECF (σ^E and σ^W), phage ECF (phiEco32 and 7-11), and group I (E. coli RpoD) σ factors. For promoters recognized by σ^E and σ^W, we extended the −10 elements 3 bp upstream in order to observe an absence of conservation in this extension. The TATA box of group I (RpoD) promoters and the analogous sequences in ECF σ promoters are boxed in blue; the sequences in the upstream −10 element extension, found in phage promoters, and the equivalent positions in σ^E and σ^W promoters are boxed in red. The coordinates of the upstream and the downstream edges of the promoter elements are indicated relative to the transcription start site.