The sequence conservation of the promoter sequence defined in PAP. (A) The fraction of genes whose promoters extend to a particular upstream or downstream position from the transcription start site. Most of the genes do not encounter another upstream gene within a distance of 10 kb, whereas only a portion of genes do not reach their translation start sites within a distance of 5 kb downstream. (B) The fraction of promoters that are conserved at a particular upstream or downstream position from the transcription start site. This fraction was calculated using the total number of promoters at each position in A as the denominator. The most conserved and alignable region is around 2 kb upstream and downstream of the annotated transcription start sites.
