title: Antagonism of the B subunit of DNA gyrase eliminates plasmids pBR322 and pMG110 from Escherichia coli.
abstract: The constructed plasmid pBR322 and the native plasmid pMG110 were eliminated (cured) from growing Escherichia coli cells by the antagonism of the B subunit of the bacterial enzyme DNA gyrase. The antagonism may be by the growth of cells (i) at semipermissive temperatures in a bacterial mutant containing a thermolabile gyrase B subunit or (ii) at semipermissive concentrations of coumermycin A1, an antibiotic that specifically inhibits the B subunit of DNA gyrase. The kinetics of plasmid elimination indicate that plasmid loss occurs too rapidly to be explained solely by the faster growth of that plasmid-free bacteria and, therefore, represents interference with plasmid maintenance.
mesh_terms: D049933:Aminocoumarins; D003374:Coumarins / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D009154:Mutation; D010957:Plasmids; D013696:Temperature; D059005:Topoisomerase II Inhibitors
chemical_list: D049933:Aminocoumarins; D003374:Coumarins; D059005:Topoisomerase II Inhibitors; C004628:coumermycin