Role of the central cations in the mechanical unfolding of DNA and RNA G-quadruplexes.

ABSTRACT: 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 [Formula: see text] 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

SUBMITTER: Bergues-Pupo AE 

PROVIDER: S-EPMC4551928 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature