DNA helicase: Difference between revisions
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DNA helicase is an [[ | DNA helicase<ref>Kitao, Saori et. al. 1998. Cloning of Two New Human Helicase Genes of the RecQ Family: Biological Significance of Multiple Species in Higher Eukaryotes. Genomics 54: 443-452.</ref> is an [[Enzyme|enzyme]] responsible for the separation of two annealed strands of [[Nucleic acids|nucleic acids]]. It binds to the double stranded [[DNA|DNA]], and breaks the [[Hydrogen bond|hydrogen bonds]] between the strands. This process allows a single-stranded [[DNA|DNA]] to form and be used as a template during [[Transcription|transcription]]. [[ATP|ATP]] [[Hydrolysis|hydrolysis]] provides the energy for the [[Enzyme|enzyme]] to translocate along the [[Double helix|double helix]] and generate a replication fork<ref>Alberts, Johnson, Lewis, Raff, Roberts, Walters. (2008) Molecular Biology of the Cell: 273, 5th edition, New York: Garland Science.</ref>. | ||
In [[Escherichia coli|''E. coli'']] DNA helicase is called the [[DnaB protein|DnaB protein]], and it differs slightly in the way it carries out it's function. DnaB forms a three-fold ring structure, with the lagging strand binding in the central region, whilst the leading strand is excluded. The DnaB translocates through a mechanism where [[DNTP|dNTP's]] bind and cause a conformational change, forcing the DNA strands to separate<ref>Alberts, Johnson, Lewis, Raff, Roberts, Walters. (2008) Molecular Biology of the Cell: 283, 5th edition, New York: Garland Science.</ref>. <br> | |||
Approximately 1% of [[Eukaryote|eukaryotic]] genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases. | |||
=== References === | === References === | ||
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Latest revision as of 12:33, 22 October 2018
DNA helicase[1] is an enzyme responsible for the separation of two annealed strands of nucleic acids. It binds to the double stranded DNA, and breaks the hydrogen bonds between the strands. This process allows a single-stranded DNA to form and be used as a template during transcription. ATP hydrolysis provides the energy for the enzyme to translocate along the double helix and generate a replication fork[2].
In E. coli DNA helicase is called the DnaB protein, and it differs slightly in the way it carries out it's function. DnaB forms a three-fold ring structure, with the lagging strand binding in the central region, whilst the leading strand is excluded. The DnaB translocates through a mechanism where dNTP's bind and cause a conformational change, forcing the DNA strands to separate[3].
Approximately 1% of eukaryotic genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases.
References
- ↑ Kitao, Saori et. al. 1998. Cloning of Two New Human Helicase Genes of the RecQ Family: Biological Significance of Multiple Species in Higher Eukaryotes. Genomics 54: 443-452.
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walters. (2008) Molecular Biology of the Cell: 273, 5th edition, New York: Garland Science.
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walters. (2008) Molecular Biology of the Cell: 283, 5th edition, New York: Garland Science.