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File:Ligation.png

2018-12-05T11:40:50Z

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The image demonstrates how [[DNA ligase|DNA ligase]] forms [[Phosphodiester_bond|phosphodiester bond]]s to join the two DNA fragments. This forms a longer DNA fragment.

File:Ligation.png

2018-12-05T11:40:03Z

180223246:

The image demonstrates how DNA ligase forms phosphodiester bonds to join the two DNA fragments. This forms a longer DNA fragment.

DNA ligase

2018-12-05T11:39:36Z

180223246:

DNA ligase is an [[Enzyme|enzyme]] that anneals [[DNA|DNA]] strands together. It forms a [[Phosphodiester bond|phosphodiester bond between]] the [[Complementary base pairs|complementary bases]] on two separate DNA strands. [[ATP|ATP]] is hydrolysed in order to release a [[Pyrophosphate|pyrophosphate]], and the [[AMP|AMP]] that is formed attaches to the 5' end of the donor. The [[Pyrophosphate|pyrophosphate]] bond activates the 5' end and a [[Phosphodiester bond|phosphodiester bond]] forms between the [[5' phosphate|5' phosphate]] and the [[3' hydroxyl|3' hydroxyl]]. [[DNA_ligase|DNA ligase]] is a crucial element in recombinant technology<ref>Alberts, Bruce. Molecular Biology of the Cell. 5th ed. New York: Garland Science, 2008, p 273</ref>.

[[DNA_ligase|DNA ligase]] is an enzyme used for the [[Ligation|ligation]] of blunt-ended and [[Sticky ends|sticky ended recombinant]] fragments or [[Okazaki fragments|Okazaki fragments]]. With blunt ends a higher [[Enzyme|enzyme]] concentration and different reaction conditions are required in comparison to when [[DNA_ligase|DNA ligase]] acts on [[Sticky ends|sticky ends]]. DNA ligase works by repairing breaks in the [[Sugar phosphate backbone|sugar phosphate backbone]] in [[DNA|DNA]] by creating a [[Covalent bond|covalent bond]] between adjoining [[Nucleotides|nucleotides]] (between the 3’[[Hydroxyl group|hydroxyl group]] of one DNA [[Molecule|molecule]] with the 5’[[Phosphoryl group|phosphoryl group]] of another)<ref>Hartl D. L., Ruvolo M. (2012), Genetics: Analysis of genes and genomes, Eight Edition, Jones and Bartlett learning (Chapter 2 DNA Structure and Genetic Variation) p440-42</ref>. In [[Eukaryotes|eukaryotes]] [[DNA ligase I|DNA ligase I]] family members play the major role. The enzyme has a fundamental role in [[Recombinant DNA Technology|genetic engineering]] such as [[Recombinant DNA Technology|recombinant plasmid formation]] or [[PCR|Polymerase Chain Reaction]]<ref>Berg, J.M., Tymoczko, J.L. and Stryer, L. (2012). Biochemistry, 7 th Edition, New York, W.H.Freeman and Co Ltd. p152-153</ref>.

[[Image:Ligation.png|Image to demonstrate how DNA ligase catalyses the formation of phosphodiester bonds between sticky ends of DNA fragments to form a longer fragment of DNA]]

=== References ===

<references />

DNA ligase

2018-12-05T11:36:25Z

180223246:

DNA ligase

2018-12-05T11:35:20Z

180223246:

DNA ligase is an [[Enzyme|enzyme]] that anneals [[DNA|DNA]] strands together. It forms a [[Phosphodiester bond|phosphodiester bond between]] the [[Complementary base pairs|complementary bases]] on two separate DNA strands. [[ATP|ATP]] is hydrolysed in order to release a [[Pyrophosphate|pyrophosphate]], and the [[AMP|AMP]] that is formed attaches to the 5' end of the donor. The [[Pyrophosphate|pyrophosphate]] bond activates the 5' end and a [[Phosphodiester bond|phosphodiester bond]] forms between the [[5' phosphate|5' phosphate]] and the [[3' hydroxyl|3' hydroxyl]]. [[DNA_ligase|DNA ligase]] is a crucial element in recombinant technology<ref>Alberts, Bruce. Molecular Biology of the Cell. 5th ed. New York: Garland Science, 2008, p 273</ref>.

[[DNA_ligase|DNA ligase]] is an enzyme used for the [[Ligation|ligation]] of blunt-ended and [[Sticky ends|sticky ended recombinant]] fragments or [[Okazaki fragments|Okazaki fragments]]. With blunt ends a higher [[Enzyme|enzyme]] concentration and different reaction conditions are required in comparison to when [[DNA_ligase|DNA ligase]] acts on [[Sticky_ends|sticky ends]]. DNA ligase works by repairing breaks in the [[Sugar phosphate backbone|sugar phosphate backbone]] in [[DNA|DNA]] by creating a [[Covalent bond|covalent bond]] between adjoining [[Nucleotides|nucleotides]] (between the 3’[[Hydroxyl group|hydroxyl group]] of one DNA [[Molecule|molecule]] with the 5’[[Phosphoryl group|phosphoryl group]] of another)<ref>Hartl D. L., Ruvolo M. (2012), Genetics: Analysis of genes and genomes, Eight Edition, Jones and Bartlett learning (Chapter 2 DNA Structure and Genetic Variation) p440-42</ref>. In [[Eukaryotes|eukaryotes]] [[DNA ligase I|DNA ligase I]] family members play the major role. The enzyme has a fundamental role in [[Recombinant DNA Technology|genetic engineering]] such as [[Recombinant DNA Technology|recombinant plasmid formation]] or [[PCR|Polymerase Chain Reaction]]<ref>Berg, J.M., Tymoczko, J.L. and Stryer, L. (2012). Biochemistry, 7 th Edition, New York, W.H.Freeman and Co Ltd. p152-153</ref>.

=== References ===

<references />

File:Ligation.png

2018-12-05T11:26:39Z

180223246: The image demonstrates how DNA ligase forms phosphodiester bonds to join the two DNA fragments. This forms a longer DNA fragment

The image demonstrates how DNA ligase forms phosphodiester bonds to join the two DNA fragments. This forms a longer DNA fragment