title: Structure of two intramolecular G-quadruplexes formed by natural human telomere sequences in K+ solution.
abstract: Intramolecular G-quadruplexes formed by human telomere sequences are attractive anticancer targets. Recently, four-repeat human telomere sequences have been shown to form two different intramolecular (3 + 1) G-quadruplexes in K(+) solution (Form 1 and Form 2). Here we report on the solution structures of both Form 1 and Form 2 adopted by natural human telomere sequences. Both structures contain the (3 + 1) G-tetrad core with one double-chain-reversal and two edgewise loops, but differ in the successive order of loop arrangements within the G-quadruplex scaffold. Our results provide the structural details at the two ends of the G-tetrad core in the context of natural sequences and information on different loop conformations. This structural information might be important for our understanding of telomere G-quadruplex structures and for anticancer drug design targeted to such scaffolds.
authors: Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. phantuan@ntu.edu.sg
authors: Anh Tuân
authors: AT
authors: Phan
authors: Vitaly
authors: V
authors: Kuryavyi
authors: Kim Ngoc
authors: KN
authors: Luu
authors: Dinshaw J
authors: DJ
authors: Patel
mesh_terms: D001483:Base Sequence; D002412:Cations; D004247:DNA / Q000737:chemistry; D054856:G-Quadruplexes; D006801:Humans; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011188:Potassium / Q000737:chemistry; D012091:Repetitive Sequences, Nucleic Acid; D012996:Solutions; D016615:Telomere / Q000737:chemistry*
chemical_list: D002412:Cations; D012996:Solutions; D004247:DNA; D011188:Potassium