Sequence motifs over-represented in nucleosome-depleted promoters. (a) An unbiased search for sequences up to 10 bp in length over-represented in nucleosome-depleted promoters (relative to promoters overall) identified the poly(dA.dT) sequence element and variants of the Rap1 consensus motif ACACCCATACAT . (b) Overlap between nucleosome-depleted promoters and promoters that contain multiple conserved motifs is shown . (c) Histogram showing average numbers of motifs in 1,000 randomly generated promoter sets. Nucleosome-depleted promoters contain an average of 6.1 conserved motifs, significantly higher than in these randomly generated sets.