Figure 3

The number of strong promoter candidate sequences is a function of the A+T content of bacterial genomes. For the score parameters sUp = 13, s35 = 5.5, s10 = 4.5 and constants c₁ = 0.22 and c₂ = -11.7, the picture displays a linear graph of the "exponential low" (thin line), which approximates fairly closely to the curve ln [N(A+T)], shown as a thick line. The logarithm of the percentage of strong promoter candidates in real genomes is shown by (○).