DNA supercoiling inhibits DNA knotting.

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Serval ID
serval:BIB_681FC248BD52
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
DNA supercoiling inhibits DNA knotting.
Journal
Nucleic Acids Research
Author(s)
Burnier Y., Dorier J., Stasiak A.
ISSN
1362-4962[electronic]
Publication state
Published
Issued date
09/2008
Peer-reviewed
Oui
Volume
36
Number
15
Pages
4956-4963
Language
english
Abstract
Despite the fact that in living cells DNA molecules are long and highly crowded, they are rarely knotted. DNA knotting interferes with the normal functioning of the DNA and, therefore, molecular mechanisms evolved that maintain the knotting and catenation level below that which would be achieved if the DNA segments could pass randomly through each other. Biochemical experiments with torsionally relaxed DNA demonstrated earlier that type II DNA topoisomerases that permit inter- and intramolecular passages between segments of DNA molecules use the energy of ATP hydrolysis to select passages that lead to unknotting rather than to the formation of knots. Using numerical simulations, we identify here another mechanism by which topoisomerases can keep the knotting level low. We observe that DNA supercoiling, such as found in bacterial cells, creates a situation where intramolecular passages leading to knotting are opposed by the free-energy change connected to transitions from unknotted to knotted circular DNA molecules.
Keywords
Computer Simulation, DNA, Circular/chemistry, DNA, Superhelical/chemistry, Models, Molecular, Monte Carlo Method, Nucleic Acid Conformation
Pubmed
Web of science
Open Access
Yes
Create date
26/11/2008 16:56
Last modification date
20/08/2019 14:23
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