Purification and properties of DNA gyrase from a fluoroquinolone-resistant strain of Escherichia coli

Abstract

Subunit A and B proteins of DNA gyrase were separately purified from fluoroquinolone-resistant Escherichia coli GN14181 (MIC of ofloxacin, 100 micrograms/ml) and susceptible strain KL-16. The supercoiling activities of reconstituted Ar+Br (r, resistant) and Ar+Bs (s, susceptible) were 250-fold more resistant to new fluoroquinolones than those of As+Bs and As+Br.