Quinolone-resistant mutations of DNA gyrase increase sensitivity to acriflavine.
DNA gyrases were constructed to possess the quinolone-resistant (D87N in GyrA or K447E in GyrB) and acrB (S759R-R760C in GyrB) mutations and their sensitivities to acriflavine and oxolinic acid were examined. Both quinolone-resistant mutations in GyrA and GyrB increased acriflavine sensitivities in the supercoiling assay irrespective of the co-presence of the acrB mutation. In the DNA binding assay, however, the hypersensitvity caused by the GyrB (K447E) mutation was observed only in the co-presence of the acrB mutation; the presence of the acrB mutation, which not affecting acriflavine sensitivity, reduces the extent of DNA binding, as reported previously. Thus, the quinolone-resistant mutation site in GyrB is likely to be involved in DNA binding which is not detectable in acrB+ gyrase. Furthermore, oxolinic acid was found to enhance DNA binding of the gyrase having GyrB (acrB-K447E), supporting a recent proposal that quinolone binding to the DNA-gyrase complex does not require DNA breakage.
Aburahi Laboratories, Shionogi & Co., Ltd., Koka, Shiga, Japan.
K
K
Funatsuki
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R
Tanaka
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S
Inagaki
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H
Konno
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K
Katoh
H
H
Nakamura
D042462:4-Quinolones; D000167:Acriflavine / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D003001:Cloning, Molecular; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D016296:Mutagenesis; D011485:Protein Binding; D059005:Topoisomerase II Inhibitors
D042462:4-Quinolones; D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D059005:Topoisomerase II Inhibitors; D000167:Acriflavine; D004250:DNA Topoisomerases, Type II