Changed properties of the A subunit in DNA gyrase with a B subunit mutation

1982 ◽  
Vol 186 (4) ◽  
pp. 572-574 ◽  
Author(s):  
E. S. Bogdanova ◽  
S. M. Mirkin ◽  
Zh. G. Shmerling
Keyword(s):  
Dna Gyrase ◽  
B Subunit ◽  
A Subunit

scholarly journals Cloning and nucleotide sequence of the gyrA gene from Campylobacter fetus subsp. fetus ATCC 27374 and characterization of ciprofloxacin-resistant laboratory and clinical isolates.

1997 ◽  
Vol 41 (3) ◽  
pp. 665-671 ◽  
Author(s):  
D E Taylor ◽  
A S Chau
Keyword(s):  
Nucleotide Sequence ◽  
Dna Gyrase ◽  
Amino Acid Identity ◽  
Gyra Gene ◽  
Reading Frame ◽  
B Subunit ◽  
Campylobacter Fetus ◽  
A Subunit ◽  
Fetus Subsp ◽  
Genomic Map

The gyrA gene of Campylobacter fetus subsp. fetus, which encodes the A subunit of DNA gyrase, was cloned, and its nucleotide sequence was determined. An open reading frame of 2,586 nucleotides which encodes a polypeptide of 862 amino acids with an Mr of 96,782 was identified. C. fetus subsp. fetus GyrA is most closely related to Campylobacter jejuni GyrA, with 73% homology at the nucleotide level and 78% identity between polypeptides. The next most closely related GyrA was that from Helicobacter pylori, with both DNA homology and amino acid identity of 63%. The gyrA and gyrB (DNA gyrase B subunit) genes were located on the genomic map of C. fetus subsp. fetus ATCC 27374 and shown to be separate. A clinical isolate of C. fetus subsp. fetus and a laboratory-derived mutant of ATCC 27374, both resistant to ciprofloxacin, had identical mutations within the quinolone resistance determining region. In both mutants a G-->T transversion, corresponding to a substitution of Asp-91 to Tyr in GyrA, was linked to ciprofloxacin resistance, giving MICs of 8 to 16 micrograms/ml.

4-(tert-butyl)-N,N-diethylbenzenesulfonamide: Structural, absorption distribution metabolism excretion toxicity (ADMET) and molecular docking studies

2021 ◽  
pp. 329-336 ◽  
Author(s):  
Gurumallappa Gurumallappa ◽  
Jayashankar Jayaprakash ◽  
Ananda A. Puttaswamy ◽  
Jayanth H. Sunderraj ◽  
Puttaswamappa Mallu ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Title Compound ◽  
Living Organism ◽  
Dna Gyrase ◽  
Docking Studies ◽  
Monoclinic Crystal ◽  
Tert Butyl ◽  
B Subunit ◽  
A Subunit ◽  
Physical And Chemical

Sulfonamides are a very good antibacterial agent that targets essential bacterial enzymes specifically DNA gyrase. The objective of the present work was to investigate the molecular docking of the (4-(tert-butyl)-N,N-diethylbenzenesulfonamide) with the DNA gyrase of S. aureus. The energy-free topoisomerase activity of the A subunit, which breaks the DNA, is inhibited by 4-quilones such as nalidixic acid and ciprofloxacin. The energy transducing activity of the B subunit is inhibited by novobiocin and other coumarin antibiotics. Single crystal X-ray diffractometer study was carried out to understand the structure, physical and chemical reactive parameters, the title compound is crystallized under monoclinic crystal system with the space group of P21/C. To understand the behaviour of the title compound in living organism, Absorption, Distribution, Metabolism, Excretion analysis was done using Swiss ADME and Osiris data warrior tool. Further, Toxicity of the title compound was predicted by using PKCSM online software.

scholarly journals Mapping Simocyclinone D8 Interaction with DNA Gyrase: Evidence for a New Binding Site on GyrB

2009 ◽  
Vol 54 (1) ◽  
pp. 213-220 ◽  
Author(s):  
C. Sissi ◽  
E. Vazquez ◽  
A. Chemello ◽  
L. A. Mitchenall ◽  
A. Maxwell ◽  
...  
Keyword(s):  
Dna Gyrase ◽  
Coumarin Derivative ◽  
Streptomyces Antibioticus ◽  
B Subunit ◽  
Terminal Domain ◽  
Antiproliferative Agent ◽  
Gyrase A ◽  
A Subunit ◽  
The Individual ◽  
Simocyclinone D8

ABSTRACT Simocyclinone D8, a coumarin derivative isolated from Streptomyces antibioticus Tü 6040, represents an interesting new antiproliferative agent. It was originally suggested that this drug recognizes the GyrA subunit and interferes with the gyrase catalytic cycle by preventing its binding to DNA. To further characterize the mode of action of this antibiotic, we investigated its binding to the reconstituted DNA gyrase (A2B2) as well as to its GyrA and GyrB subunits and the individual domains of these proteins, by performing protein melting and proteolytic digestion studies as well as inhibition assays. Two binding sites were identified, one (anticipated) in the N-terminal domain of GyrA (GyrA59) and the other (unexpected) at the C-terminal domain of GyrB (GyrB47). Stabilization of the A subunit appears to be considerably more effective than stabilization of the B subunit. Our data suggest that these two distinct sites could cooperate in the reconstituted enzyme.

scholarly journals Impact of Amino Acid Substitutions in B Subunit of DNA Gyrase in Mycobacterium leprae on Fluoroquinolone Resistance

2012 ◽  
Vol 6 (10) ◽  
pp. e1838 ◽  
Author(s):  
Kazumasa Yokoyama ◽  
Hyun Kim ◽  
Tetsu Mukai ◽  
Masanori Matsuoka ◽  
Chie Nakajima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mycobacterium Leprae ◽  
Dna Gyrase ◽  
Fluoroquinolone Resistance ◽  
Amino Acid Substitutions ◽  
B Subunit

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.

Control of protein phosphatase 2A by simian virus 40 small-t antigen

1991 ◽  
Vol 11 (4) ◽  
pp. 1988-1995
Author(s):  
S I Yang ◽  
R L Lickteig ◽  
R Estes ◽  
K Rundell ◽  
G Walter ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Simian Virus 40 ◽  
Histone H1 ◽  
Simian Virus ◽  
T Antigen ◽  
Light Chains ◽  
B Subunit ◽  
Phosphatase 2A ◽  
A Subunit ◽  
Small T Antigen

Soluble, monomeric simian virus 40 (SV40) small-t antigen (small-t) was purified from bacteria and assayed for its ability to form complexes with protein phosphatase 2A (PP2A) and to modify its catalytic activity. Different forms of purified PP2A, composed of combinations of regulatory subunits (A and B) with a common catalytic subunit (C), were used. The forms used included free A and C subunits and AC and ABC complexes. Small-t associated with both the free A subunit and the AC form of PP2A, resulting in a shift in mobility during nondenaturing polyacrylamide gel electrophoresis. Small-t did not interact with the free C subunit or the ABC form. These data demonstrate that the primary interaction is between small-t and the A subunit and that the B subunit of PP2A blocks interaction of small-t with the AC form. The effect of small-t on phosphatase activity was determined by using several exogenous substrates, including myosin light chains phosphorylated by myosin light-chain kinase, myelin basic protein phosphorylated by microtubule-associated protein 2 kinase/ERK1, and histone H1 phosphorylated by protein kinase C. With the exception of histone H1, small-t inhibited the dephosphorylation of these substrates by the AC complex. With histone H1, a small stimulation of dephosphorylation by AC was observed. Small-t had no effect on the activities of free C or the ABC complex. A maximum of 50 to 75% inhibition was obtained, with half-maximal inhibition occurring at 10 to 20 nM small-t. The specific activity of the small-t/AC complex was similar to that of the ABC form of PP2A with myosin light chains or histone H1 as the substrate. These results suggested that small-t and the B subunit have similar qualitative and quantitative effects on PP2A enzyme activity. These data show that SV40 small-antigen binds to purified PP2A in vitro, through interaction with the A subunit, and that this interaction inhibits enzyme activity.

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