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Involvement of topoisomerase IV and DNA gyrase as ciprofloxacin targets in Streptococcus pneumoniae
TLDR
In both laboratory strains and clinical isolates, ParC mutations preceded those in GyrA, suggesting that topoisomersase IV is a primary topoisomerase target and gyrase is a secondary target for ciprofloxacin in S. pneumoniae. Expand
Targeting of DNA gyrase in Streptococcus pneumoniae by sparfloxacin: selective targeting of gyrase or topoisomerase IV by quinolones
  • X. Pan, L. Fisher
  • Biology, Medicine
  • Antimicrobial agents and chemotherapy
  • 1 February 1997
TLDR
The targeting of gyrase by sparfloxacin in S. pneumoniae but of topoisomerase IV by ciprofloxACin indicates that target preference can be altered by changes in quinolone structure. Expand
Structural insight into the quinolone–DNA cleavage complex of type IIA topoisomerases
TLDR
The structures of cleavage complexes formed by the Streptococcus pneumoniae ParC breakage-reunion and ParE TOPRIM domains of topoisomerase IV stabilized by moxifloxacin and clinafloxacIn help explain antibacterial quinolone action and resistance. Expand
4-Quinolone resistance mutations in the DNA gyrase of Escherichia coli clinical isolates identified by using the polymerase chain reaction
  • M. Oram, L. Fisher
  • Biology, Medicine
  • Antimicrobial Agents and Chemotherapy
  • 1 February 1991
TLDR
Seven nalidixic acid-resistant clinical isolates of Escherichia coli were shown to carry resistance mutations in their gyrase A proteins; the frequent occurrence of a mutation at serine-83 implies a key role for this residue in quinolone action. Expand
Structural Basis of Gate-DNA Breakage and Resealing by Type II Topoisomerases
TLDR
X-ray crystallography is used to study sequential states in the formation and reversal of a DNA cleavage complex by topoisomerase IV from Streptococcus pneumoniae, the bacterial type II enzyme involved in chromosome segregation to suggest how a type II enzymes reseals DNA during its normal reaction cycle and illuminate aspects of drug arrest important for the development of new topoisomersase-targeting therapeutics. Expand
Novel Gyrase Mutations in Quinolone-Resistant and -Hypersusceptible Clinical Isolates of Mycobacterium tuberculosis: Functional Analysis of Mutant Enzymes
TLDR
Describing several multidrug-resistant clinical isolates of M. tuberculosis carrying mutations in the genes encoding the GyrA or GyrB subunits associated with quinolone resistance or hypersusceptibility found that several isolates bearing a novel combination of gyrA T80A and A90G changes were hypersuceptible to ofloxacin. Expand
Cloning and characterization of a DNA gyrase A gene from Escherichia coli that confers clinical resistance to 4-quinolones
TLDR
It is shown that the Ser-83----Trp mutation in the gyrase A protein was solely responsible for high-level bacterial resistance to nalidixic acid and fluoroquinolones. Expand
DNA Gyrase and Topoisomerase IV Are Dual Targets of Clinafloxacin Action in Streptococcus pneumoniae
  • Xiao-Su Pan, L. Fisher
  • Biology, Medicine
  • Antimicrobial Agents and Chemotherapy
  • 1 November 1998
TLDR
The results suggested that clinafloxacin displays comparable if unequal targeting of gyrase and topoisomerase IV and its first- and second-step mutants are desirable features in limiting the emergence of bacterial resistance. Expand
DNA gyrase gyrA mutations in ciprofloxacin-resistant strains of Staphylococcus aureus: close similarity with quinolone resistance mutations in Escherichia coli
TLDR
These substitutions occur in a region of the gyrase A protein wherein directly analogous mutations of serine 83----leucine and alanine 84----proline in Escherichia coli confer quinolone resistance. Expand
Cloning and characterization of the parC and parE genes of Streptococcus pneumoniae encoding DNA topoisomerase IV: role in fluoroquinolone resistance
TLDR
The results suggest that DNA topoisomerase IV is an important target for fluoroquinolones in S. pneumoniae and establish this organism as a useful gram-positive system for resistance studies. Expand
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