title: DNA: bihelical structure, supercoiling, and relaxation.
mesh_terms: D004247:DNA; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004269:DNA, Bacterial; D004270:DNA, Circular; D004278:DNA, Superhelical; D004926:Escherichia coli; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000648:ultrastructure; D010957:Plasmids
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular; D004278:DNA, Superhelical; D009707:Nucleosomes; D004247:DNA; D004264:DNA Topoisomerases, Type I; D004250:DNA Topoisomerases, Type II