Specific alignment of nucleosomes on DNA correlates with periodic distribution of purine—pyrimidine and pyrimidine—purine dimers

摘要

>Comparison of the X-ray data and results of conformational analysis reveals the sequence-dependent helical anisotropy of DNA: purine—pyrimidine (RY) and pyrmidine—purine (YR) dimers prefer bending in the opposite directions. On this basis it is suggested that in the optimal nucleosomal DNA sequence the RY and YR dinucleotides alternate at intervals of 5–6 basepairs. Examination of the cases with the known disposition of nucleosomes confirms this concept.