title: Dynamics and stability of polymorphic human telomeric G-quadruplex under tension.
abstract: As critical DNA structures capping the human chromosome ends, the stability and structural polymorphism of human telomeric G-quadruplex (G4) have drawn increasing attention in recent years. This work characterizes the equilibrium transitions of single-molecule telomeric G4 at physiological K(+) concentration. We report three folded states of telomeric G4 with markedly different lifetime and mechanical stability. Our results show that the kinetically favored folding pathway is through a short-lived intermediate state to a longer-lived state. By examining the force dependence of transition rates, the force-dependent transition free energy landscape for this pathway is determined. In addition, an ultra-long-lived form of telomeric G4 structure with a much stronger mechanical stability is identified.
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore.
authors.forename: Huijuan
authors.initials: H
authors.lastname: You
authors.affiliation: School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore.
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, 117456, Singapore Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, 117546, Singapore.
authors.forename: Ci Ji
authors.initials: CJ
authors.lastname: Lim
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore.
authors.forename: Artem K
authors.initials: AK
authors.lastname: Efremov
authors.affiliation: School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Anh Tuân
authors.initials: AT
authors.lastname: Phan
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, 117456, Singapore Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, 117546, Singapore Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore phyyj@nus.edu.sg.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
mesh_terms: D001696:Biomechanical Phenomena; D054856:G-Quadruplexes; D006801:Humans; D007700:Kinetics; D016615:Telomere / Q000737:chemistry*