The pattern and evolution of yeast promoter bendability.

In Saccharomyces cerevisiae, transcription factor binding sites are found preferentially approximately 100-200 bp upstream of the start codon. Here, we show that this region is associated with rigid DNA in promoters lacking a TATA box, but not in TATA-containing promoters. The association of rigid DNA with transcription factor binding sites is conserved in TATA-less promoters from 11 yeast species, whereas the position of the rigid DNA varies substantially among species. Rigid DNA could influence nucleosome positioning and assist in the assembly of the transcriptional machinery at TATA-less promoters.