DNA supercoiling and its role in DNA decatenation and unknotting.

Détails

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Etat: Public
Version: de l'auteur
ID Serval
serval:BIB_0F19F8CEC35D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
DNA supercoiling and its role in DNA decatenation and unknotting.
Périodique
Nucleic Acids Research
Auteur(s)
Witz G., Stasiak A.
ISSN
1362-4962[electronic], 0305-1048[linking]
Statut éditorial
Publié
Date de publication
2010
Peer-reviewed
Oui
Volume
38
Numéro
7
Pages
2119-2133
Langue
anglais
Résumé
Chromosomal and plasmid DNA molecules in bacterial cells are maintained under torsional tension and are therefore supercoiled. With the exception of extreme thermophiles, supercoiling has a negative sign, which means that the torsional tension diminishes the DNA helicity and facilitates strand separation. In consequence, negative supercoiling aids such processes as DNA replication or transcription that require global- or local-strand separation. In extreme thermophiles, DNA is positively supercoiled which protects it from thermal denaturation. While the role of DNA supercoiling connected to the control of DNA stability, is thoroughly researched and subject of many reviews, a less known role of DNA supercoiling emerges and consists of aiding DNA topoisomerases in DNA decatenation and unknotting. Although DNA catenanes are natural intermediates in the process of DNA replication of circular DNA molecules, it is necessary that they become very efficiently decatenated, as otherwise the segregation of freshly replicated DNA molecules would be blocked. DNA knots arise as by-products of topoisomerase-mediated intramolecular passages that are needed to facilitate general DNA metabolism, including DNA replication, transcription or recombination. The formed knots are, however, very harmful for cells if not removed efficiently. Here, we overview the role of DNA supercoiling in DNA unknotting and decatenation.
Mots-clé
DNA Topoisomerases, Type II, Bacterial/metabolism, DNA, Bacterial/chemistry, DNA, Bacterial/metabolism, DNA, Catenated/chemistry, DNA, Circular/chemistry, DNA, Superhelical/chemistry, DNA, Superhelical/ultrastructure, Models, Molecular, Nucleic Acid Conformation
Pubmed
Web of science
Open Access
Oui
Création de la notice
27/01/2010 18:07
Dernière modification de la notice
20/08/2019 12:35
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