Initiator motif and dinucleotide preference of core promoters in S. cerevisiae. Sequence logo demonstrating a consensus sequence of 20 nt surrounding the dominant TSS of inducible core promoters (A) and constitutive core promoters (B), which likely represents the Initiator element in yeast. (C) TSSs in S. cerevisiae have a strong preference of pyrimidine–purine dinucleotide at [+1,−1] positions in both constitutive and inducible core promoters. The constitutive core promoter has a significantly higher frequency of dinucleotide with “A” and the +1 position (CA, and TA), whereas the inducible core promoter has a significantly higher frequency of “G” at the −1 position. (*) P < 0.01, χ2 test.
