In the past, type IB topoisomerases were referred to as eukaryotic topoisomerase I, but IB topoisomerases are present in all three domains of life. Type IB topoisomerases form a covalent intermediate with the 3' end of DNA. Type IC topoisomerase (also called Topoisomerase V) has been identified.
Topoisomerase is an enzyme which participates in the unwinding of DNA helix….During transcription and DNA replication, the DNA needs to be unwound in order for the ...
Topoisomerase IV is one of two type-II topoisomerases in bacteria, the other being DNA gyrase.Like gyrase, topoisomerase IV is able to pass one double-strand of DNA through another double-strand of DNA, thereby changing the linking number of DNA by two in each enzymatic step.
What does Topoisomerase II Inhibitors mean in English?
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Definition of topoisomerase in the Definitions.net dictionary. Meaning of topoisomerase. What does topoisomerase mean? Information and translations of topoisomerase in the most comprehensive dictionary definitions resource on the web.
Topoisomerases serve to maintain both the transcription and replication of DNA. Aside from topoisomerases I and II, there are more discovered topoisomerases. Topoisomerase III may regulate recombination while topoisomerase IV regulates the process of segregating newly replicated chromosomes from one another.
You are right, helicases and topoisomerases are two different classes of enzymes. DNA gyrase is a specific example of a topoisomerase. Helicases unwind double-stranded DNA (among a few other activities that we haven't talked about) and in the process break hydrogen bonds. Topoisomerases work on double-stranded DNA to relive or induce supercoils.
A nice clip i found on the mechanisms of action of topoisomerase 1 and 2.
Topoisomerase II inhibitors can cause a wide range of chromosomal aberrations, and can act by either stabilising topoisomerase II-DNA complexes that are easily cleaved, or by interfering with the catalytic activity of the enzyme, both resulting in double-strand breaks in the DNA.