Structure, sequence and ion-exchange of left-handed G-quadruplexes

• Main Author: Bakalar, Blaz
• Other Authors: Phan Anh Tuan
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: DRNTU::Science::Biological sciences::Biophysics
• Online Access: https://hdl.handle.net/10356/106467; http://hdl.handle.net/10220/47993
• Institution: Nanyang Technological University

Besides the canonical double-stranded helical B-DNA structure, DNA can form four-stranded G-quadruplex structures composed of stacked guanine G-tetrads. Until the recent first example of a left-handed structure named Z-G4, all solved G-quadruplex structures adopted a right-handed helical fold. We report on the discovery of five new left-handed G-quadruplex structures, including a minimal left-handed motif. These structures and associated findings help pave the way towards expanding the primary sequence requirements for left-handed G-quadruplexes. Cations are important for G-quadruplex assembly as they bind between stacked G-tetrads. We have observed a cation coordinated in Z-G4 that has an exchange time on the order of one hour at room temperature.