title: Folding of the DNA double helix in chromatin-like structures from simian virus 40.
abstract: Relaxed circular, covalently closed simian virus 40 DNA molecules were associated with the four histones that are present in virions. In electron micrographs the resulting complexes appear twisted, with globular structures (nucleosomes) along the DNA. Incubation with an untwisting extract converts the twisted complexes to relaxed structures. Extraction of the DNA from the relaxed complexes yields supercoiled molecules. The number of superhelical turns in these molecules corresponds to the number of nucleosomes per DNA molecule in the complexes.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002843:Chromatin / Q000032:analysis*; D004262:DNA Restriction Enzymes; D004270:DNA, Circular; D004279:DNA, Viral; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology; D000882:Haplorhini; D006657:Histones; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D012685:Sepharose; D013539:Simian virus 40 / Q000032:analysis*; D014764:Viral Proteins
chemical_list: D002843:Chromatin; D004270:DNA, Circular; D004279:DNA, Viral; D006657:Histones; D014764:Viral Proteins; D012685:Sepharose; D004262:DNA Restriction Enzymes