Editing Nucleosome (section)

=== H2A and H2B ===
In contrast to old H3 and H4, the old [[Histone H2A|H2A]] and [[Histone H2B|H2B]] histone proteins are released and degraded; therefore, newly assembled H2A and H2B proteins are incorporated into new nucleosomes.<ref>{{cite journal | vauthors = Louters L, Chalkley R | title = Exchange of histones H1, H2A, and H2B in vivo | journal = Biochemistry | volume = 24 | issue = 13 | pages = 3080–3085 | date = June 1985 | pmid = 4027229 | doi = 10.1021/bi00334a002 }}</ref> H2A and H2B are assembled into dimers which are then loaded onto nucleosomes by the nucleosome assembly protein-1 (NAP-1) which also assists with nucleosome sliding.<ref>{{cite journal | vauthors = Park YJ, Chodaparambil JV, Bao Y, McBryant SJ, Luger K | title = Nucleosome assembly protein 1 exchanges histone H2A-H2B dimers and assists nucleosome sliding | journal = The Journal of Biological Chemistry | volume = 280 | issue = 3 | pages = 1817–1825 | date = January 2005 | pmid = 15516689 | doi = 10.1074/jbc.M411347200 | doi-access = free }}</ref> The nucleosomes are also spaced by ATP-dependent nucleosome-remodeling complexes containing enzymes such as Isw1 Ino80, and Chd1, and subsequently assembled into higher order structure.<ref>{{cite journal | vauthors = Vincent JA, Kwong TJ, Tsukiyama T | title = ATP-dependent chromatin remodeling shapes the DNA replication landscape | journal = Nature Structural & Molecular Biology | volume = 15 | issue = 5 | pages = 477–484 | date = May 2008 | pmid = 18408730 | pmc = 2678716 | doi = 10.1038/nsmb.1419 }}</ref><ref>{{cite journal | vauthors = Yadav T, Whitehouse I | title = Replication-Coupled Nucleosome Assembly and Positioning by ATP-Dependent Chromatin-Remodeling Enzymes | journal = Cell Reports | volume = 15 | issue = 4 | pages = 715–723 | date = April 2016 | pmid = 27149855 | pmc = 5063657 | doi = 10.1016/J.CELREP.2016.03.059 }}</ref>