Figure 3.

Average promoter and gene properties as a function of the number of binding sites. (a) Average binding site length. (b) Fraction of essential genes. (c) Sum of expression correlations. (d) Fraction of binding sites that are 'new' (not conserved in other species). P values for the displayed correlations are as follows: (a), 10^-42; (b), 6 × 10^-7; (c), 10^-16; and (d), 10^-22. Dashed red lines show the linear line that best matches the data points. Graphs show promoters of up to 15 binding sites. These constitute 97% of the promoters for which data are available.