32788 20210121114541.0 doi 10.1093/nar/gkv690 sideral 91969 ART-2015-91969 eng (orcid)0000-0002-6568-4138 Bergues-Pupo, A. Role of the central cations in the mechanical unfolding of DNA and RNA G-quadruplexes 2015 Access copy available to the general public Unrestricted Cations are known to mediate diverse interactions in nucleic acids duplexes but they are critical in the arrangement of four-stranded structures. Here, we use all-atom molecular dynamics simulations with explicit solvent to analyse the mechanical unfolding of representative intramolecular G-quadruplex structures: a parallel, a hybrid and an antiparallel DNA and a parallel RNA, in the presence of stabilising cations. We confirm the stability of these conformations in the presence of K+ central ions and observe distortions from the tetrad topology in their absence. Force-induced unfolding dynamics is then investigated. We show that the unfolding events in the force-extension curves are concomitant to the loss of coordination between the central ions and the guanines of the G-quadruplex. We found lower ruptures forces for the parallel configuration with respect to the antiparallel one, while the behaviour of the force pattern of the parallel RNA appears similar to the parallel DNA. We anticipate that our results will be essential to interpret the fine structure rupture profiles in stretching assays at high resolution and will shed light on the mechanochemical activity of G-quadruplex-binding machinery. info:eu-repo/grantAgreement/ES/MINECO/MAT2013-49455-EXP info:eu-repo/grantAgreement/ES/MINECO/FIS2014-55867-P info:eu-repo/grantAgreement/ES/MINECO/FIS2011-25167 info:eu-repo/grantAgreement/ES/DGA/E19 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 9.202 2015 BIOCHEMISTRY & MOLECULAR BIOLOGY 18 / 289 = 0.062 2015 Q1 T1 7.358 2015 Genetics 2015 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Arias-Gonzalez, J. (orcid)0000-0001-5775-483X Morón, M.C. Universidad de Zaragoza (orcid)0000-0001-6859-099X Fiasconaro, A. Universidad de Zaragoza (orcid)0000-0002-9551-624X Falo, F. Universidad de Zaragoza 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 43, 15 (2015), 7638-7647 Nucleic acids res. Nucleic Acids Research 0305-1048 4076923 http://zaguan.unizar.es/record/32788/files/texto_completo.pdf Versión publicada 144092 http://zaguan.unizar.es/record/32788/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:32788 articulos driver 2021-01-21-11:16:13 ARTICLE