title: Active chromatin.
abstract: Active genes are packaged into an altered nucleosome structure forming a chromosomal domain defined by increased sensitivity to nucleases. This structure, reflecting a potential for transcription, contains sites hypersensitive to nuclease digestion adjacent to the coding regions and may also be distinguished by specific non-histone proteins, variant or modified histones or modified DNA. Its formation, by unfolding of a tightly packed chromatin fibre by factors which might affect DNA supercoiling, may be the first step in gene activation.
mesh_terms: D000818:Animals; D001483:Base Sequence; D011232:Chemical Precipitation; D002843:Chromatin / Q000502:physiology* / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology; D005786:Gene Expression Regulation; D006609:High Mobility Group Proteins; D006657:Histones / Q000502:physiology; D006801:Humans; D008745:Methylation; D009707:Nucleosomes / Q000648:ultrastructure*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006609:High Mobility Group Proteins; D006657:Histones; D009707:Nucleosomes