DNA topoisomerase: Difference between revisions
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| [[DNA|DNA]] topoisomerase plays an impotant role in breaking the [[Phosphodiester bond|phosphodiester bond]] by binding covalently onto the DNA backbone [[Phosphate|phosphate]]. It acst as a [[Reversible nuclease|reversible nuclease]]. This whole process is a reversible one, whereby before the [[Proteins|protein]] leaves, the phosophodiester bonds are re-made. There are two types of DNA topoisomerase, [[DNA topoisomerase I|topoisomerase I]] and [[DNA topoisomerase II|topoismerase II]]<ref>Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.</ref>. | ||
== '''Topoisomerase I''' == | |||
Topoisomerase I catalyses the cleavage of the double stranded DNA by relaxing the supercoiled DNA. This process releases energy, as it is thermodynamically favourable <ref>Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.</ref>.<br> | |||
Topoisomerase I catalyses the cleavage of the double stranded DNA by relaxing the supercoiled DNA. This process releases energy, as it is thermodynamically favourable <ref>Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.</ref>. | |||
== '''Topoisomerase II''' == | == '''Topoisomerase II''' == | ||
Topoisomerase II cleaves the double stranded DNA by adding negative supercoils to DNA. This process hydrolyses ATP to produce the required energy <ref>Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.</ref>.<br> | Topoisomerase II cleaves the double stranded DNA by adding negative supercoils to DNA. This process hydrolyses [[ATP|ATP]] to produce the required energy <ref>Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.</ref>.<br> | ||
=== Reference === | === Reference === | ||
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Revision as of 07:05, 12 October 2014
DNA topoisomerase plays an impotant role in breaking the phosphodiester bond by binding covalently onto the DNA backbone phosphate. It acst as a reversible nuclease. This whole process is a reversible one, whereby before the protein leaves, the phosophodiester bonds are re-made. There are two types of DNA topoisomerase, topoisomerase I and topoismerase II[1].
Topoisomerase I
Topoisomerase I catalyses the cleavage of the double stranded DNA by relaxing the supercoiled DNA. This process releases energy, as it is thermodynamically favourable [2].
Topoisomerase II
Topoisomerase II cleaves the double stranded DNA by adding negative supercoils to DNA. This process hydrolyses ATP to produce the required energy [3].
Reference
- ↑ Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.
- ↑ Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.
- ↑ Berg, J., Tymoczko, J., Stryer, L. and Berg, J. (2011). Student companion for Biochemistry, 7th edition, international edition. 1st ed. New York: W.H. Freeman.