title: The nucleosome surface regulates chromatin compaction and couples it with transcriptional repression.
abstract: Although it is believed that the interconversion between permissive and refractory chromatin structures is important in regulating gene transcription, this process is poorly understood. Central to addressing this issue is to elucidate how a nucleosomal array folds into higher-order chromatin structures. Such findings can then provide new insights into how the folding process is regulated to yield different functional states. Using well-defined in vitro chromatin-assembly and transcription systems, we show that a small acidic region on the surface of the nucleosome is crucial both for the folding of a nucleosomal template into the 30-nm chromatin fiber and for the efficient repression of transcription, thereby providing a mechanistic link between these two essential processes. This structure-function relationship has been exploited by complex eukaryotic cells through the replacement of H2A with the specific variant H2A.Bbd, which naturally lacks an acidic patch.
authors.affiliation: The John Curtin School of Medical Research, The Australian National University, PO Box 334, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Zhou
authors.forename: Jun Y
authors.initials: JY
authors.lastname: Fan
authors.forename: Danny
authors.initials: D
authors.lastname: Rangasamy
authors.forename: David J
authors.initials: DJ
authors.lastname: Tremethick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D005786:Gene Expression Regulation; D006801:Humans; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D012492:Salts / Q000737:chemistry; D016415:Sequence Alignment; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D046911:Macromolecular Substances; D009707:Nucleosomes; D012492:Salts