scholarly journals Interaction of the Plasmid-Encoded Quinolone Resistance Protein QnrA with Escherichia coli Topoisomerase IV

2005 ◽  
Vol 49 (7) ◽  
pp. 3050-3052 ◽  
Author(s):  
John H. Tran ◽  
George A. Jacoby ◽  
David C. Hooper
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Topoisomerase Iv ◽  
Displacement Assay ◽  
Resistance Protein

ABSTRACT Purified QnrA blocked ciprofloxacin inhibition of topoisomerase IV, just as QnrA was previously found to prevent quinolone inhibition of DNA gyrase. With a gel displacement assay, tagged QnrA was shown to bind to topoisomerase IV and its subunits in a reaction that did not depend on the presence of DNA, quinolone, or ATP.

scholarly journals Transferable Quinolone Resistance in Vibrio cholerae

2009 ◽  
Vol 54 (2) ◽  
pp. 799-803 ◽  
Author(s):  
Hong Bin Kim ◽  
Minghua Wang ◽  
Sabeena Ahmed ◽  
Chi Hye Park ◽  
Regina C. LaRocque ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vibrio Cholerae ◽  
Dna Gyrase ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
A Subunit ◽  
Resistant Strains ◽  
Over Time

ABSTRACT Ciprofloxacin was introduced for treatment of patients with cholera in Bangladesh because of resistance to other agents, but its utility has been compromised by the decreasing ciprofloxacin susceptibility of Vibrio cholerae over time. We correlated levels of susceptibility and temporal patterns with the occurrence of mutation in gyrA, which encodes a subunit of DNA gyrase, followed by mutation in parC, which encodes a subunit of DNA topoisomerase IV. We found that ciprofloxacin activity was more recently further compromised in strains containing qnrVC3, which encodes a pentapeptide repeat protein of the Qnr subfamily, members of which protect topoisomerases from quinolone action. We show that qnrVC3 confers transferable low-level quinolone resistance and is present within a member of the SXT integrating conjugative element family found commonly on the chromosomes of multidrug-resistant strains of V. cholerae and on the chromosomes of Escherichia coli transconjugants constructed in the laboratory. Thus, progressive increases in quinolone resistance in V. cholerae are linked to cumulative mutations in quinolone targets and most recently to a qnr gene on a mobile multidrug resistance element, resulting in further challenges for the antimicrobial therapy of cholera.

scholarly journals A Mutation in Escherichia coli DNA Gyrase Conferring Quinolone Resistance Results in Sensitivity to Drugs Targeting Eukaryotic Topoisomerase II

2004 ◽  
Vol 48 (12) ◽  
pp. 4495-4504 ◽  
Author(s):  
Thomas Gruger ◽  
John L. Nitiss ◽  
Anthony Maxwell ◽  
E. Lynn Zechiedrich ◽  
Peter Heisig ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Cleavage ◽  
Topoisomerase Ii ◽  
Antimicrobial Agents ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Quinolone Resistance ◽  
Site Directed Mutagenesis ◽  
Type Ii ◽  
Topoisomerase Iv

ABSTRACT Fluoroquinolones are broad-spectrum antimicrobial agents that target type II topoisomerases. Many fluoroquinolones are highly specific for bacterial type II topoisomerases and act against both DNA gyrase and topoisomerase IV. In Escherichia coli, mutations causing quinolone resistance are often found in the gene that encodes the A subunit of DNA gyrase. One common site for resistance-conferring mutations alters Ser83, and mutations to Leu or Trp result in high levels of resistance to fluoroquinolones. In the present study we demonstrate that the mutation of Ser83 to Trp in DNA gyrase (GyrS83W) also results in sensitivity to agents that are potent inhibitors of eukaryotic topoisomerase II but that are normally inactive against prokaryotic enzymes. Epipodophyllotoxins, such as etoposide, teniposide and amino-azatoxin, inhibited the DNA supercoiling activity of GyrS83W, and the enzyme caused elevated levels of DNA cleavage in the presence of these agents. The DNA sequence preference for GyrS83W-induced cleavage sites in the presence of etoposide was similar to that seen with eukaryotic type II topoisomerases. Introduction of the GyrS83W mutation in E. coli strain RFM443-242 by site-directed mutagenesis sensitized it to epipodophyllotoxins and amino-azatoxin. Our results demonstrate that sensitivity to agents that target topoisomerase II is conserved between prokaryotic and eukaryotic enzymes, suggesting that drug interaction domains are also well conserved and likely occur in domains important for the biochemical activities of the enzymes.

scholarly journals Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in quinolone-resistant clinical isolates of Klebsiella pneumoniae.

1997 ◽  
Vol 41 (3) ◽  
pp. 699-701 ◽  
Author(s):  
T Deguchi ◽  
A Fukuoka ◽  
M Yasuda ◽  
M Nakano ◽  
S Ozeki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Primary Target ◽  
Gyra Gene ◽  
Topoisomerase Iv ◽  
Complementary Role

We determined a partial sequence of the Klebsiella pneumoniae parC gene, including the region analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene, and examined 26 clinical strains of K. pneumoniae for an association of alterations in GyrA and ParC with susceptibilities to quinolones. The study suggests that in K. pneumoniae DNA gyrase is a primary target of quinolones and that ParC alterations play a complementary role in the development of higher-level fluoroquinolone resistance.

scholarly journals Interaction of the Plasmid-Encoded Quinolone Resistance Protein Qnr with Escherichia coli DNA Gyrase

2005 ◽  
Vol 49 (1) ◽  
pp. 118-125 ◽  
Author(s):  
John H. Tran ◽  
George A. Jacoby ◽  
David C. Hooper
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Catalytic Cycle ◽  
Repeat Family ◽  
Biochemical Basis ◽  
Chromosomal Genes ◽  
Resistance Protein ◽  
Cleavage Complex ◽  
Gyrase Inhibitors

ABSTRACT Quinolone resistance normally arises by mutations in the chromosomal genes for type II topoisomerases and by changes in the expression of proteins that control the accumulation of quinolones inside bacteria. A novel mechanism of plasmid-mediated quinolone resistance was recently reported that involves DNA gyrase protection by a pentapeptide repeat family member called Qnr. This family includes two other members, McbG and MfpA, that are also involved in resistance to gyrase inhibitors. Purified Qnr-His6 was shown to protect Escherichia coli DNA gyrase directly from inhibition by ciprofloxacin. Here we have provided a biochemical basis for the mechanism of quinolone resistance. We have shown that Qnr can bind to the gyrase holoenzyme and its respective subunits, GyrA and GyrB. The binding of Qnr to gyrase does not require the presence of the complex of enzyme, DNA, and quinolone, since binding occurred in the absence of relaxed DNA, ciprofloxacin, or ATP. We hypothesize that the formation of Qnr-gyrase complex occurs before the formation of the cleavage complex. Furthermore, there was a decrease in DNA binding by gyrase when the enzyme interacted with Qnr. Therefore, it is possible that the reaction intermediate recognized by Qnr is one early in the gyrase catalytic cycle, in which gyrase has just begun to interact with DNA. Quinolones bind later in the catalytic cycle and stabilize a ternary complex consisting of the drug, gyrase, and DNA. By lowering gyrase binding to DNA, Qnr may reduce the amount of holoenzyme-DNA targets for quinolone inhibition.

scholarly journals Cloning and Nucleotide Sequences of the Topoisomerase IV parC and parE Genes ofMycoplasma hominis

1998 ◽  
Vol 42 (8) ◽  
pp. 2024-2031 ◽  
Author(s):  
Cécile M. Bébéar ◽  
Alain Charron ◽  
Joseph Marie Bové ◽  
Christiane Bébéar ◽  
Joel Renaudin
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Active Site ◽  
Mycoplasma Hominis ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Topoisomerase Iv ◽  
Atp Binding Site ◽  
Gram Positive Bacteria

ABSTRACT The topoisomerase IV parC and parE genes from the wall-less organism Mycoplasma hominis PG21 were cloned and sequenced. The coupled genes are located far from the DNA gyrase genes gyrA and gyrB. They encode proteins of 639 and 866 amino acids, respectively. As expected, the encoded ParE and ParC proteins exhibit higher homologies with the topoisomerase IV subunits of the gram-positive bacteriaStaphylococcus aureus and Streptococcus pneumoniae than with their Escherichia colicounterparts. The conserved regions include the Tyr residue of the active site and the region involved in quinolone resistance (quinolone resistance-determining region [QRDR]) in ParC and the ATP-binding site and the QRDR in ParE.

scholarly journals Differential behaviors of Staphylococcus aureus and Escherichia coli type II DNA topoisomerases.

1996 ◽  
Vol 40 (12) ◽  
pp. 2714-2720 ◽  
Author(s):  
F Blanche ◽  
B Cameron ◽  
F X Bernard ◽  
L Maton ◽  
B Manse ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Strong Support ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Type Ii ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Dna Relaxation

Staphylococcus aureus gyrA and gyrB genes encoding DNA gyrase subunits were cloned and coexpressed in Escherichia coli under the control of the T7 promoter-T7 RNA polymerase system, leading to soluble gyrase which was purified to homogeneity. Purified gyrase was catalytically indistinguishable from the gyrase purified from S. aureus and did not contain detectable amounts of topoisomerases from the E. coli host. Topoisomerase IV subunits GrlA and GrlB from S. aureus were also expressed in E. coli and were separately purified to apparent homogeneity. Topoisomerase IV, which was reconstituted by mixing equimolar amounts of GrlA and GrlB, had both ATP-dependent decatenation and DNA relaxation activities in vitro. This enzyme was more sensitive than gyrase to inhibition by typical fluoroquinolone antimicrobial agents such as ciprofloxacin or sparfloxacin, adding strong support to genetic studies which indicate that topoisomerase IV is the primary target of fluoroquinolones in S. aureus. The results obtained with ofloxacin suggest that this fluoroquinolone could also primarily target gyrase. No cleavable complex could be detected with S. aureus gyrase upon incubation with ciprofloxacin or sparfloxacin at concentrations which fully inhibit DNA supercoiling. This suggests that these drugs do not stabilize the open DNA-gyrase complex, at least under standard in vitro incubation conditions, but are more likely to interfere primarily with the DNA breakage step, contrary to what has been reported with E. coli gyrase. Both S. aureus gyrase-catalyzed DNA supercoiling and S. aureus topoisomerase IV-catalyzed decatenation were dramatically stimulated by potassium glutamate or aspartate (500- and 50-fold by 700 and 350 mM glutamate, respectively), whereas topoisomerase IV-dependent DNA relaxation was inhibited 3-fold by 350 mM glutamate. The relevance of the effect of dicarboxylic amino acids on the activities of type II topoisomerases is discussed with regard to the intracellular osmolite composition of S. aureus.

scholarly journals Quinolone-resistant mutants of escherichia coli DNA topoisomerase IV parC gene.

1996 ◽  
Vol 40 (3) ◽  
pp. 710-714 ◽  
Author(s):  
Y Kumagai ◽  
J I Kato ◽  
K Hoshino ◽  
T Akasaka ◽  
K Sato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Mutant Gene ◽  
Missense Mutations ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
E Coli ◽  
A Subunit ◽  
Resistant Strains ◽  
Mutant Genes

Escherichia coli quinolone-resistant strains with mutations of the parC gene, which codes for a subunit of topoisomerase IV, were isolated from a quinolone-resistant gyrA mutant of DNA gyrase. Quinolone-resistant parC mutants were also identified among the quinolone-resistant clinical strains. The parC mutants became susceptible to quinolones by introduction of a parC+ plasmid. Introduction of the multicopy plasmids carrying the quinolone-resistant parC mutant gene resulted in an increase in MICs of quinolones for the parC+ and quinolone-resistant gyrA strain. Nucleotide sequences of the quinolone-resistant parC mutant genes were determined, and missense mutations at position Gly-78, Ser-80, or Glu-84, corresponding to those in the quinolone-resistance-determining region of DNA gyrase, were identified. These results indicate that topoisomerase IV is a target of quinolones in E. coli and suggest that the susceptibility of E. coli cells to quinolones is determined by sensitivity of the targets, DNA gyrase and topoisomerase IV.

scholarly journals Quinolones: Mechanism, Lethality and Their Contributions to Antibiotic Resistance

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5662
Author(s):  
Natassja G. Bush ◽  
Isabel Diez-Santos ◽  
Lauren R. Abbott ◽  
Anthony Maxwell
Keyword(s):  
Cell Death ◽  
Antibiotic Resistance ◽  
Dna Gyrase ◽  
Mechanisms Of Action ◽  
Quinolone Resistance ◽  
Topoisomerase Iv ◽  
Bacterial Enzymes ◽  
Dna Topoisomerase ◽  
Quinolone Antibiotics ◽  
Dna Complex

Fluoroquinolones (FQs) are arguably among the most successful antibiotics of recent times. They have enjoyed over 30 years of clinical usage and become essential tools in the armoury of clinical treatments. FQs target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, where they stabilise a covalent enzyme-DNA complex in which the DNA is cleaved in both strands. This leads to cell death and turns out to be a very effective way of killing bacteria. However, resistance to FQs is increasingly problematic, and alternative compounds are urgently needed. Here, we review the mechanisms of action of FQs and discuss the potential pathways leading to cell death. We also discuss quinolone resistance and how quinolone treatment can lead to resistance to non-quinolone antibiotics.

scholarly journals Mutation in the DNA Gyrase A Gene ofEscherichia coli That Expands the Quinolone Resistance-Determining Region

2001 ◽  
Vol 45 (8) ◽  
pp. 2378-2380 ◽  
Author(s):  
S. Marvin Friedman ◽  
Tao Lu ◽  
Karl Drlica
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Dna Gyrase ◽  
Ofescherichia Coli ◽  
Quinolone Resistance ◽  
Gyrase A

ABSTRACT In three Escherichia coli mutants, a change (Ala-51 to Val) in the gyrase A protein outside the standard quinolone resistance-determining region (QRDR) lowered the level of quinolone susceptibility more than changes at amino acids 67, 82, 84, and 106 did. Revision of the QRDR to include amino acid 51 is indicated.

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