Nucleosomal arrays self-assemble into supramolecular globular structures lacking 30-nm fibers.

ABSTRACT: The existence of a 30-nm fiber as a basic folding unit for DNA packaging has remained a topic of active discussion. Here, we characterize the supramolecular structures formed by reversible Mg(2+)-dependent self-association of linear 12-mer nucleosomal arrays using microscopy and physicochemical approaches. These reconstituted chromatin structures, which we call "oligomers", are globular throughout all stages of cooperative assembly and range in size from ~50 nm to a maximum diameter of ~1,000 nm. The nucleosomal arrays were packaged within the oligomers as interdigitated 10-nm fibers, rather than folded 30-nm structures. Linker DNA was freely accessible to micrococcal nuclease, although the oligomers remained partially intact after linker DNA digestion. The organization of chromosomal fibe

SUBMITTER: Maeshima K 

PROVIDER: S-EPMC4868957 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature