title: Structure of nucleosome core particles of chromatin.
abstract: Cystals have been obtained on nucleosome cores and analysed by X-ray diffraction and electron microscopy. The core is a flat particle of dimensions about 110 X 110 X 57 A, somewhat wedge shaped, and strongly divided into two 'layers', consistent with the DNA being wound into about 1 3/4 turns of a flat superhelix of a pitch about 28 A. The organisation of the DNA can be correlated with the results to enzyme digestion studies. A change in the screw of the DNA double helix on nucleosome formation can be deduced.
mesh_terms: D000818:Animals; D002843:Chromatin / Q000648:ultrastructure*; D003460:Crystallization; D004247:DNA; D003851:Deoxyribonucleases / Q000378:metabolism; D006657:Histones; D008099:Liver / Q000648:ultrastructure; D008854:Microscopy, Electron; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D051381:Rats; D014961:X-Ray Diffraction
chemical_list: D002843:Chromatin; D006657:Histones; D004247:DNA; D003851:Deoxyribonucleases