Results 241 to 250 of about 57,780 (287)
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BACTERIAL DIVERSITY BASED ON TYPE II DNA TOPOISOMERASE GENES
Annual Review of Genetics, 1996▪ Abstract Type II DNA topoisomerases are essential and ubiquitous DNA metabolic enzymes that alter DNA topology. Eubacteria have two indispensable type II DNA topoisomerases, DNA gyrase encoded by gyrB and gyrA and topoisomerase IV encoded by parE and parC. These genes belong to a single family whose members span both eukaryotes and prokaryotes. The
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Quinolones, 2-Pyridones and Resistant Type II DNA Topoisomerases
Current Pharmaceutical Design, 1997Abstract: DNA gyrase and topoisomerase IV, the bacterial type II DNA topoisomerases, are known to be the targets of fluoroquinolones. The l1uoroquinolones have rapid bactericidal action derived from their dual actions to inhibit the catalytic activity of the essential enzymes and to form a stable enzyme-DNA cleavable complex.
Linus. L. Shen +2 more
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A new compound, withangulatin A, promotes type II DNA topoisomerase-mediated DNA damage
Biochemical and Biophysical Research Communications, 1989Withangulatin A, a new compound with a known chemical structure and from the antitumor Chinese herb Physalis angulata L, was found to act on topoisomerase II to induce topoisomerase II-mediated DNA damage in vitro. It has two effective dosage ranges of approximate 0.5 and 20 microM, with about one-third the activity of 20 microM VM-26.
J K, Juang +3 more
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Expression and cellular localization of Trypanosoma cruzi type II DNA topoisomerase
Molecular and Biochemical Parasitology, 1998Topoisomerases are enzymes that participate in many cellular functions involving topological manipulation of DNA strands. There are two types of topoisomerases in the cell: (a) type I topoisomerases; and (b) type II topoisomerases (topo II). Previously we have cloned and sequenced the gene encoding Trypanosoma cruzi topo II (TcTOP2).
S P, Fragoso +4 more
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Simplification of DNA Topology Below Equilibrium Values by Type II Topoisomerases
Science, 1997Type II DNA topoisomerases catalyze the interconversion of DNA topoisomers by transporting one DNA segment through another. The steady-state fraction of knotted or catenated DNA molecules produced by prokaryotic and eukaryotic type II topoisomerases was found to be as much as 80 times lower than at thermodynamic equilibrium.
V V, Rybenkov +3 more
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Single-molecule analysis of DNA uncoiling by a type II topoisomerase
Nature, 2000Type II DNA topoisomerases are ubiquitous ATP-dependent enzymes capable of transporting a DNA through a transient double-strand break in a second DNA segment. This enables them to untangle DNA and relax the interwound supercoils (plectonemes) that arise in twisted DNA.
T R, Strick, V, Croquette, D, Bensimon
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19 DNA Gyrase and Other Type II Topoisomerases
1981Publisher Summary DNA topoisomerases are enzymes that catalyze changes in the topological structure of DNA molecules. The basic chemical reaction carried out by topoisomerases is a cycle of breakage and rejoining of DNA chains, in the course of which the phosphodiester bond energy is conserved by the formation of a covalent enzyme–DNA intermediate ...
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Topology, Type II DNA Topoisomerases and DNA Replication in Prokaryotes and Eukaryotes
1983DNA replication raises several topological questions. i) How did the two parental strands uncoil in spite of the restriction imposed to their rotation either by DNA circularity or by the barriers which segregate the chromosome into topologically independent domains? ii) How is tangling of the two daughter duplexes avoided? Which mechanism generates the
Patrick Forterre +2 more
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Type II DNA topoisomerases: Coupling directional DNA transport to ATP hydrolysis
2003Publisher Summary This chapter describes the mechanism of the type II enzymes and focuses on the present knowledge about the way these enzymes couple adenosine triphosphate (ATP) binding and hydrolysis to the directional transport of one duplex DNA segment through a transient break in another. Type II topoisomerases are essential in all organisms for
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