title: HMG proteins (1 + 2) form beaded structures when complexed with closed circular DNA.
abstract: Structures bearing a resemblance to nucleosomes can be assembled by incubating calf thymus High Mobility Group proteins (1 + 2) with closed circular DNA. These HMG proteins are capable of forming beads and inducing superhelicity when bound to DNA. However, they do not protect from nuclease digestion the discrete DNA fragments characteristic of nucleosomes. The relationship between HMGs (1 + 2) and the "primitive" histone-like DNA-packaging proteins from prokaryotes and mitochondria is discussed.
mesh_terms: D000818:Animals; D002417:Cattle; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004270:DNA, Circular / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D006609:High Mobility Group Proteins; D006657:Histones; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D009707:Nucleosomes / Q000648:ultrastructure; D011485:Protein Binding; D013539:Simian virus 40; D013950:Thymus Gland
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004270:DNA, Circular; D004279:DNA, Viral; D006609:High Mobility Group Proteins; D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes