Figure 1

Occurrence of sequence motifs in coding and non-coding DNA. The genomes of Streptomyces coelicolor (A), S. avermitilis (B), Mycobacterium tuberculosis (C) and Escherichia coli (D) were scanned against each matrix to find matches to the corresponding DNA sequence motifs. The scanning method assigned a score (maximum 100) to each match site. Scans were performed using a range of different threshold minimum scores. For each threshold, we counted the number of match sites (with a score of equal to or greater than the threshold) found in coding and in non-coding DNA (i.e. intragenic and intergenic sites respectively). The ratio of the number of intergenic sites to the number of intragenic sites is plotted for each threshold level that was used. The matrices are further described in Table 1.