Results 211 to 220 of about 79,794 (267)
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Bacillus anthracis pXO1 virulence plasmid encodes a type 1 DNA topoisomerase
Molecular Microbiology, 1994SummaryThe virulence plasmid pXO1 is responsible for toxin production in Bacillus anthracis. A DNA fragment from pXO1 was isolated and was shown, by sequence analysis, to contain part of a type 1 DNA topoisomerase gene. Attempts to clone the entire wild‐type gene, designated topX, in Escherichia coli, were unsuccessful.
A, Fouet, J C, Sirard, M, Mock
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Purification and characterization of a type I DNA topoisomerase from calf thymus mitochondria
Biochemistry, 1987A type I topoisomerase has been purified more than 4000-fold from calf thymus mitochondria. The enzyme is membrane associated and is effectively solubilized by 1% Triton X-100 treatment of purified mitochondrial inner membranes. This ATP-independent enzyme relaxes positively and negatively supercoiled DNA with delta LK = 1.
G M, Lazarus +4 more
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Human Type I DNA Topoisomerase: Regulation of Expression and Function
1992The replication of DNA requires two fundamental steps, namely an unwinding of the parental DNA double helix and the utilization of the emerging single strand sequences as templates for the synthesis of progeny DNA strands. The unwinding of the double helix is catalyzed by DNA helicases breaking the hydrogen bonds between complementary DNA strands at ...
R. Knippers +4 more
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Biochemical basis for the interactions of type I and type II topoisomerases with DNA
Pharmacology & Therapeutics, 1989DNA topoisomerases are complex and unique enzymes which alter the topological state of DNA without changing its chemical structure. Between the type I and II enzymes, topoisomerases carry out a multitude of reactions, including DNA binding, site specific DNA cleavage/religation, relaxation, catenation/decatenation, and knotting/unknotting of nucleic ...
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Escherichia coli DNA topoisomerase III: purification and characterization of a new type I enzyme
Biochemistry, 1984A new topoisomerase capable of relaxing negatively supercoiled DNA in Escherichia coli has been identified during chromatography on novobiocin-Sepharose. A simple and reproducible purification procedure is described to obtain this enzyme, called topoisomerase III (topo III), in a homogeneous form.
K S, Srivenugopal +2 more
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In vitro analysis of a type I DNA topoisomerase activity from cultured tobacco cells
Plant Molecular Biology, 1992The role of DNA topoisomerases in plant cell metabolism is currently under investigation in our laboratory. Using a purified type I topoisomerase from cultured tobacco, we have carried out a biochemical characterization of enzymatic behavior. The enzyme relaxes negatively supercoiled DNA in the presence of MgCl2, and to a lesser extent in the presence ...
A D, Cole +3 more
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Antitumor Inhibitors of DNA Topoisomerases
Current pharmaceutical design, 1995DNA topoisomerases are nuclear enzymes that regulate DNA topology during transcription , replication and recombination processes, and are essential for the integrity of the genetic material.
G. Capranico, F. Zunino
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Role of DNA topoisomerase I in the replication of herpes simplex virus type 2
Archives of Virology, 1990Camptothecin (CPT), a specific inhibitor of DNA topoisomerase I, effectively inhibited the replication of herpes simplex virus type 2 (HSV-2). CPT was found to reduce the level of immediate early viral mRNA in a dose-response manner. On the other hand, we could not find any evidence that a novel DNA topoisomerase I was induced in HSV-2-infected cells ...
Y, Yamada +3 more
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Diospyrin, A Bisnaphthoquinone: A Novel Inhibitor of Type I DNA Topoisomerase of Leishmania donovani
Molecular Pharmacology, 1998Diospyrin is a plant product that has significant inhibitory effect on the growth of Leishmania donovani promastigotes. This compound inhibits the catalytic activity of DNA topoisomerase I of the parasite. Like camptothecin, it induces topoisomerase I mediated DNA cleavage in vitro. Treatment of DNA with diospyrin before addition of topoisomerase I has
S, Ray +4 more
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Biochemical and Biophysical Research Communications, 1983
2-6 dimethyl-9-hydroxyellipticinium inhibited the relaxation of supercoiled DNA by the type I topoisomerase of T. cruzi. Since DNA relaxed in the presence of an intercalating drug prior to electrophoresis became supercoiled when the ligand was removed, we analysed the topoisomerisation in gels containing another ligand, chloroquine.
S, Douc-Rasy, A, Kayser, G, Riou
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2-6 dimethyl-9-hydroxyellipticinium inhibited the relaxation of supercoiled DNA by the type I topoisomerase of T. cruzi. Since DNA relaxed in the presence of an intercalating drug prior to electrophoresis became supercoiled when the ligand was removed, we analysed the topoisomerisation in gels containing another ligand, chloroquine.
S, Douc-Rasy, A, Kayser, G, Riou
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