Conserved sequences in promoters associated with genes encoding the translational machinery. (A) and (B) are Weblog representations  without and with changing the length of the spacer of individual promoters to maximise alignment of the −35 box (Additional file 7). The combined height of nucleotide symbols shows the level of sequence conservation at a particular position, while the height of individual symbols within a stack of nucleotides indicates the relative frequency at that position. The nucleotide positions are numbered relative to the average position of TSSs. In (B) numbering only extends to the point at which gaps were introduced to maximise the alignment.