LexA regulon. A) Plot of the average expression level of the members of the LexA regulon across the different conditions. Red dots mark conditions with high (>0.8) correlation between the genes in LexA regulon. The horizontal bar and its different regions indicated by numbers refer to the classification of the conditions as described in Materials and Methods. High expression levels are observed in conditions corresponding to low pH or UV light. B) Clusters of genes involved in DNA repair mechanisms in the co-expression network (obtained from the combination of R
λ and C
λ with λ=√2). Genes regulated by LexA are marked red. C) Refined LexA identified binding motif, positions 14 and 15 were previously non specific. D) Number of genes identified to be regulated by LexA. Previous indicates genes previously reported in the literature as LexA regulated , whereas Automatic refers to the genes initially identified by the automatic biclustering algorithm.