title: DNA gyrase and topoisomerase IV: biochemical activities, physiological roles during chromosome replication, and drug sensitivities.
abstract: DNA gyrase and topoisomerase IV are the two type II topoisomerases present in bacteria. Though clearly related, based on amino acid sequence similarity, they each play crucial, but distinct, roles in the cell. Gyrase is involved primarily in supporting nascent chain elongation during replication of the chromosome, whereas topoisomerase IV separates the topologically linked daughter chromosomes during the terminal stage of DNA replication. These different roles can be attributed to differences in the biochemical properties of the two enzymes. The biochemical activities, physiological roles, and drug sensitivities of the enzymes are reviewed.
authors.affiliation: Graduate Program in Molecular Biology, Cornell University Graduate School of Medical Sciences, New York, NY, USA.
authors.forename: C
authors.initials: C
authors.lastname: Levine
authors.forename: H
authors.initials: H
authors.lastname: Hiasa
authors.forename: K J
authors.initials: KJ
authors.lastname: Marians
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology; D002875:Chromosomes / Q000235:genetics; D003374:Coumarins / Q000494:pharmacology; D004261:DNA Replication / Q000235:genetics*; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D004926:Escherichia coli / Q000201:enzymology; D015363:Quinolones / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000201:enzymology
chemical_list: D001426:Bacterial Proteins; D003374:Coumarins; D004791:Enzyme Inhibitors; D015363:Quinolones; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II