The nucleosome core particle: does it have structural and physiologic relevance?

Although the nucleosomal core particle has been extensively studied as the basic building block of chromatin, the biological significance of a unit ca rrying exactly 146 bp of DNA remains unclear. Herein, we present data to sh ow that the histone octamer can stably accommodate anywhere from:about 100 to 170 bp of DNA. The unfolded structures containing less than 146 bp may w ell be of greater biological importance than the canonical core particle. ( C) 1999 John Wiley & Sons, Inc.