DNA topoisomerase: Difference between revisions
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DNA topoisomerase plays an important role in breaking the phosphodiester bond by binding covalently onto the DNA backbone phosphate<ref>Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.</ref>. It acts as a reversible nuclease. This whole process is a reversible one, whereby before the protein leaves, the phosphodiester bonds are re-made. There are two types of DNA topoisomerase, topoisomerase I and topoisomerase II<ref>Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.</ref>. <br> === Reference | DNA topoisomerase plays an important role in breaking the phosphodiester bond by binding covalently onto the DNA backbone phosphate<ref>Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.</ref>. It acts as a reversible nuclease. This whole process is a reversible one, whereby before the protein leaves, the phosphodiester bonds are re-made. There are two types of DNA topoisomerase, topoisomerase I and topoisomerase II<ref>Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.</ref>. | ||
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== '''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><br> | |||
== '''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> | |||
=== Reference === | |||
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Revision as of 06:38, 12 October 2014
DNA topoisomerase plays an important role in breaking the phosphodiester bond by binding covalently onto the DNA backbone phosphate[1]. It acts as a reversible nuclease. This whole process is a reversible one, whereby before the protein leaves, the phosphodiester bonds are re-made. There are two types of DNA topoisomerase, topoisomerase I and topoisomerase II[2].
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 [3].
Topoisomerase II
Topoisomerase II cleaves the double stranded DNA by adding negative supercoils to DNA. This process hydrolyses ATP to produce the required energy [4].
Reference
- ↑ Alberts, BA, 2008. Molecular Biology of The Cell. 5th ed. New York: Garland Science.
- ↑ 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.