P53 Functional Positional Prior

The plot above from Riley et al. 2009 shows the estimated relative affinities of 158 experimentally validated, functional p53-binding sites versus their distance from the Transcription Start Site (TSS). Functional low-affinity sites exist in a tight band around the TSS (cyan vertical line). p53 activation-sites are plotted in green, repression-sites in red, and both activation and repression sites in black. The three functional positional priors are linear (blue), square root (black), and logarithmic (orange) formulas based on the distance of the binding sites from the TSS. The logarithmic functional positional prior (orange) has a false negative rate of 5 out of 158 validated, functional p53 binding sites.