title: Folding pathways of hybrid-1 and hybrid-2 G-quadruplex structures.
abstract: The G-rich sequence in the human telomeric DNA can form the G-quadruplex structure. The G-quadruplex structure has become an attractive target for the anticancer drugs, because it effectively inhibits telomerase activity. Recently, the human telomere G-quadruplex in K(+) solution has been determined as a hybrid structure. This structure is called hybrid-1. More recently, the hybrid-2 G-quadruplex has been determined by NMR. Hybrid-2 G-quadruplex differs from hybrid-1 in its loop arrangement and strand orientation. Here, we propose the folding pathways of hybrid-1 and hybrid-2 G-quadruplex structures. In hybrid-1, we proposed two pathways. In one pathway, the random coil forms triplex-1; in another pathway, the random coil forms chair-1. Similarly, we proposed two pathways in hybrid-2. In one pathway, the random coil forms triplex-2; in another pathway, the random coil forms chair-2. The folding pathways of human telomeric hybrid-1 G-quadruplex and hybrid-2 G-quadruplex structures were proposed using MO calculation and molecular modelling.
authors.affiliation: Department of Chemistry, Graduate Schoool of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Mashimo
authors.forename: Yuta
authors.initials: Y
authors.lastname: Sannohe
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Yagi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugiyama
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry; D054856:G-Quadruplexes; D006801:Humans; D008958:Models, Molecular; D016615:Telomere / Q000737:chemistry*
chemical_list: D004247:DNA