A common mechanical property shared by yeast nucleosomal DNAs

Abstract

Mechanical properties of DNA have long been thought to play an important role in the packaging of genomic DNA in the nucleus. Using two parameter sets for the flexibility of short base-pair steps, the average flexibility profile of 199 yeast nucleosomal DNAs was calculated. Dramatically decreased flexibilities, or rigid peaks, were observed at intervals of about 10 bp in the profile. Furthermore, it was found that the phase of the rigid peaks overlapped with the phase of the high AA/TT occurrence. These results seem to indicate that periodically spaced rigid regions help DNA to contact with histone core with high affinity.