Replication-guided nucleosome packing and nucleosome breathing expedite the formation of dense arrays.

ABSTRACT: The first level of genome packaging in eukaryotic cells involves the formation of dense nucleosome arrays, with DNA coverage near 90% in yeasts. How cells achieve such high coverage within a short time, e.g. after DNA replication, remains poorly understood. It is known that random sequential adsorption of impenetrable particles on a line reaches high density extremely slowly, due to a jamming phenomenon. The nucleosome-shifting action of remodeling enzymes has been proposed as a mechanism to resolve such jams. Here, we suggest two biophysical mechanisms which assist rapid filling of DNA with nucleosomes, and we quantitatively characterize these mechanisms within mathematical models. First, we show that the 'softness' of nucleosomes, due to nucleosome breathing and stepwise nucleosome assem

SUBMITTER: Osberg B 

PROVIDER: S-EPMC4267636 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature