title: A sign inversion mechanism for enzymatic supercoiling of DNA.
abstract: Both the introduction and the removal of supertwists by DNA gyrase change the linking number of DNA in steps of two. This surprising finding provides strong evidence that gyrase acts by a mechanism, called sign inversion, whereby a positive supercoil is directly inverted into a negative one via a transient double-strand break.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004278:DNA, Superhelical; D004926:Escherichia coli / Q000201:enzymology; D008954:Models, Biological; D009690:Nucleic Acid Conformation
chemical_list: D004278:DNA, Superhelical; D000255:Adenosine Triphosphate; D004250:DNA Topoisomerases, Type II