title: Crystallographic structure of the octameric histone core of the nucleosome at a resolution of 3.3 A.
abstract: The structure of the (H2A-H2B-H3-H4)2 histone octamer has been determined by means of x-ray crystallographic techniques at a resolution of 3.3 angstroms. The octamer is a prolate ellipsoid 110 angstroms long and 65 to 70 angstroms in diameter, and its general shape is that of a rugby ball. The size and shape are radically different from those determined in earlier studies. The most striking feature of the histone octamer is its tripartite organization, that is, a central (H3-H4)2 tetramer flanked by two H2A-H2B dimers. The DNA helix, placed around the octamer in a path suggested by the features on the surface of the protein, appears like a spring holding the H2A-H2B dimers at either end of the (H3-H4)2 tetramer.
mesh_terms: D000818:Animals; D002645:Chickens; D002843:Chromatin / Q000648:ultrastructure; D004247:DNA / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D008956:Models, Chemical; D009707:Nucleosomes / Q000648:ultrastructure*; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D004247:DNA