(Top) Motif discovery with Gibbs Sampling on a set of LexA protein sequences from different bacterial phyla. Instances of the discovered motif are highlighted on the sequences using the superimposed output option. The detected 10 amino acid-long motif shown in the consensus logo is centered on the well characterized Ala-Gly cleavage site of LexA . (Bottom) Dyad Motif search on the E. coli K-12 MG1655 lexA (b4043) promoter region (see Figure 4), with 4±1 bp dyad, 8±1 bp spacer and 2 allowed mismatches. The reported score is the sum of dyad mismatch scores.