English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/174216
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


DNA knots occur in intracellular chromatin

AuthorsValdés, Antonio ; Segura, Joana ; Dyson, Sílvia ; Martínez-García, Belén ; Roca, Joaquim
Issue Date25-Jan-2018
PublisherOxford University Press
CitationNucleic Acids Research 46(2): 650–660 (2017)
AbstractIn vivo DNA molecules are narrowly folded within chromatin fibers and self-interacting chromatin domains. Therefore, intra-molecular DNA entanglements (knots) might occur via DNA strand passage activity of topoisomerase II. Here, we assessed the presence of such DNA knots in a variety of yeast circular minichromosomes. We found that small steady state fractions of DNA knots are common in intracellular chromatin. These knots occur irrespective of DNA replication and cell proliferation, though their abundance is reduced during DNA transcription. We found also that in vivo DNA knotting probability does not scale proportionately with chromatin length: it reaches a value of ∼0.025 in domains of ∼20 nucleosomes but tends to level off in longer chromatin fibers. These figures suggest that, while high flexibility of nucleosomal fibers and clustering of nearby nucleosomes facilitate DNA knotting locally, some mechanism minimizes the scaling of DNA knot formation throughout intracellular chromatin. We postulate that regulation of topoisomerase II activity and the fractal architecture of chromatin might be crucial to prevent a potentially massive and harmful self-entanglement of DNA molecules in vivo.
Publisher version (URL)https://doi.org/10.1093/nar/gkx1137
Appears in Collections:(IBMB) Artículos
Files in This Item:
File Description SizeFormat 
DNA_knots_Valdés.pdf10,81 MBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.