title: Nucleosomes can invade DNA territories occupied by their neighbors.
abstract: Nucleosomes are the fundamental subunits of eukaryotic chromatin. They are not static entities, but can undergo a number of dynamic transitions, including spontaneous repositioning along DNA. As nucleosomes are spaced close together within genomes, it is likely that on occasion they approach each other and may even collide. Here we have used a dinucleosomal model system to show that the 147-base-pair (bp) DNA territories of two nucleosomes can overlap extensively. In the situation of an overlap by 44 bp or 54 bp, one histone dimer is lost and the resulting complex can condense to form a compact single particle. We propose a pathway in which adjacent nucleosomes promote DNA unraveling as they approach each other and that this permits their 147-bp territories to overlap, and we suggest that these events may represent early steps in a pathway for nucleosome removal via collision.
authors.affiliation: Wellcome Trust Centre for Gene Regulation and Expression, University of Dundee, Dundee, DD1 5EH, UK.
authors.forename: Maik
authors.initials: M
authors.lastname: Engeholm
authors.forename: Martijn
authors.initials: M
authors.lastname: de Jager
authors.forename: Andrew
authors.initials: A
authors.lastname: Flaus
authors.forename: Ruth
authors.initials: R
authors.lastname: Brenk
authors.forename: John
authors.initials: J
authors.lastname: van Noort
authors.forename: Tom
authors.initials: T
authors.lastname: Owen-Hughes
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009707:Nucleosomes / Q000737:chemistry / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D009707:Nucleosomes; D004247:DNA