title: Relationship between chromatin high-order folding and nucleosomal linker twist in nuclei of human HeLa s3 cells.
abstract: We have used the intercalative agent ethidium bromide to examine the association between chromatin high-order folding and the twist of internucleosomal DNA regions. The analysis was carried out on intact nuclei isolated from human HeLa S3 cells. Our data shows that alterations in the nucleosomal linker twist significantly influence the way in which a chain of nucleosomes folds to form different higher-order structures. The assay used allowed us to identify the existence of two chromatin fractions differing in their extent of high-order folding. We have also found that active gene sequences are preferentially associated with the chromatin fraction corresponding to the more extended conformation. A model is proposed to account for the effect of variations in the nucleosome linker twist on the state of chromatin folding.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, BC, Canada.
authors.forename: W A
authors.initials: WA
authors.lastname: Krajewski
authors.forename: J
authors.initials: J
authors.lastname: Ausió
mesh_terms: D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure*; D002843:Chromatin / Q000187:drug effects / Q000648:ultrastructure*; D004273:DNA, Neoplasm / Q000737:chemistry* / Q000187:drug effects; D004996:Ethidium / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D007364:Intercalating Agents / Q000494:pharmacology; D008961:Models, Structural; D009690:Nucleic Acid Conformation / Q000187:drug effects; D009707:Nucleosomes / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D002843:Chromatin; D004273:DNA, Neoplasm; D007364:Intercalating Agents; D009707:Nucleosomes; D004996:Ethidium