topoisomerase iv การใช้

• It is believed that eukaryotic cells do not contain DNA gyrase or topoisomerase IV.
• However, when Topoisomerase IV alone was inhibited, decatenation was almost completely blocked.
• Both gyrase and topoisomerase IV CTDs bend DNA, but only gyrase introduces negative supercoils.
• Topoisomerase IV in " E . coli " unlinks or decatenates the two circular DNA duplexes.
• Fourth generation fluoroquinolones act at DNA gyrase and topoisomerase IV . This dual action slows development of resistance.
• Fourth-generation fluoroquinolones act at DNA gyrase and topoisomerase IV . This dual action slows development of resistance.
• Nalidixic acid and related antibiotics inhibit a subunit of DNA gyrase and topoisomerase IV and induce formation of cleavage complexes.
• While topoisomerase IV does relax positive supercoils like DNA gyrase, it does not introduce further negative supercoiling like the latter enzyme.
• For many gram-negative bacteria, DNA gyrase is the target, whereas topoisomerase IV is the target for many gram-positive bacteria.
• Finally, mutations at key sites in DNA gyrase or topoisomerase IV can decrease their binding affinity to quinolones, decreasing the drugs'effectiveness.
• For many Gram-negative bacteria, DNA gyrase is the target, whereas topoisomerase IV is the target for many Gram-positive bacteria.
• Finally, mutations at key sites in DNA gyrase or topoisomerase IV can decrease their binding affinity to quinolones, decreasing the drug's effectiveness.
• The ability of gyrase ( and topoisomerase IV ) to relax positive supercoils allows superhelical tension ahead of the polymerase to be released so that replication can continue.
• In an experiment conducted by Zechiedrich, Khodursky and Cozzarelli in 1997, it was found that topoisomerase IV is the only important decatenase of DNA replication intermediates in bacteria.
• It functions by inhibiting DNA gyrase, a type II topoisomerase, and topoisomerase IV, which is an enzyme necessary to separate, replicated DNA, thereby inhibiting cell division.
• It is believed eukaryotic cells do not contain DNA gyrase or topoisomerase IV . However, there is debate concerning whether the quinolones still have such an adverse effect on the DNA of healthy cells
• In E . coli, DNA topoisomerase IV plays the major role in the separation of the catenated chromosomes, transiently breaking both DNA strands of one chromosome and allowing the other chromosome to pass through the break.
• Topoisomerase IV also relaxes positive supercoils, therefore, DNA Gyrase and topoisomerase IV play an almost identical role in removing the positive supercoils ahead of a translocating DNA polymerase, allowing DNA replication to continue unhindered by topological strain.
• Topoisomerase IV also relaxes positive supercoils, therefore, DNA Gyrase and topoisomerase IV play an almost identical role in removing the positive supercoils ahead of a translocating DNA polymerase, allowing DNA replication to continue unhindered by topological strain.
• We often forget that DNA gyrase does in fact have topoisomerase type II activity; thus, with it being a homologue of topoisomerase IV ( also having topoisomerase II activity ) we expect similarity in the two proteins'functions.