scholarly journals Corrigenda: SecA defects are accompanied by dysregulation of MukB, DNA gyrase, chromosome partitioning and DNA superhelicity in Escherichia coli

Microbiology ◽  
2020 ◽  
Vol 166 (12) ◽  
pp. 1194-1194
Author(s):  
Shun Adachi ◽  
Yasuhiro Murakawa ◽  
Sota Hiraga
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Chromosome Partitioning

scholarly journals SecA defects are accompanied by dysregulation of MukB, DNA gyrase, chromosome partitioning and DNA superhelicity in Escherichia coli

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1648-1658 ◽  
Author(s):  
Shun Adachi ◽  
Yasuhiro Murakawa ◽  
Sota Hiraga
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Molecular Mechanisms ◽  
Protein Translocation ◽  
Genetic Interaction ◽  
Acyl Carrier Protein ◽  
Dna Gyrase ◽  
Spatial Regulation ◽  
Chromosome Partitioning ◽  
Structural Maintenance Of Chromosomes

Spatial regulation of nucleoids and chromosome-partitioning proteins is important for proper chromosome partitioning in Escherichia coli. However, the underlying molecular mechanisms are unknown. In the present work, we showed that mutation or chemical perturbation of secretory A (SecA), an ATPase component of the membrane protein translocation machinery, SecY, a component of the membrane protein translocation channel and acyl carrier protein P (AcpP), which binds to SecA and MukB, a functional homologue of structural maintenance of chromosomes protein (SMC), resulted in a defect in chromosome partitioning. We further showed that SecA is essential for proper positioning of the oriC DNA region, decatenation and maintenance of superhelicity of DNA. Genetic interaction studies revealed that the topological abnormality observed in the secA mutant was due to combined inhibitory effects of defects in MukB, DNA gyrase and Topo IV, suggesting a role for the membrane protein translocation machinery in chromosome partitioning and/or structural maintenance of chromosomes.

scholarly journals Cloning and simplified purification of Escherichia coli DNA gyrase A and B proteins.

1984 ◽  
Vol 259 (14) ◽  
pp. 9199-9201 ◽  
Author(s):  
K Mizuuchi ◽  
M Mizuuchi ◽  
M H O'Dea ◽  
M Gellert
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Gyrase A

Multiple modes of Escherichia coli DNA gyrase activity revealed by force and torque

2007 ◽  
Vol 14 (4) ◽  
pp. 264-271 ◽  
Author(s):  
Marcelo Nöllmann ◽  
Michael D Stone ◽  
Zev Bryant ◽  
Jeff Gore ◽  
Nancy J Crisona ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Multiple Modes

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.

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