title: Solution structure of a small-molecular ligand complexed with CAG trinucleotide repeat DNA.
abstract: NMR structure of the first identified ligand, naphthyridine-azaquinolone (NA), complexed with the CAG-CAG triad is reported. The determined structure revealed the invasive ligands binding to the A-A mismatch and flanking G-C base pairs, causing the widowed cytosines to flip out from pi-stack. Hydrogen-bond pairs between NA and DNA, naphthyridine-guanine and azaquinolone-adenine, are well stacked in the right-handed DNA helix, showing structural mimicry of Watson-Crick base pairing. This is the first observation that the small molecular ligand induced the base flipping of the nucleotide base in the Watson-Crick base pair.
authors.affiliation: Graduate School of Engineering, Kyoto University, Kyoto 618-8510, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakatani
authors.forename: Shinya
authors.initials: S
authors.lastname: Hagihara
authors.forename: Yuki
authors.initials: Y
authors.lastname: Goto
authors.forename: Akio
authors.initials: A
authors.lastname: Kobori
authors.forename: Masaki
authors.initials: M
authors.lastname: Hagihara
authors.forename: Gosuke
authors.initials: G
authors.lastname: Hayashi
authors.forename: Motoki
authors.initials: M
authors.lastname: Kyo
authors.forename: Makoto
authors.initials: M
authors.lastname: Nomura
authors.forename: Masaki
authors.initials: M
authors.lastname: Mishima
authors.forename: Chojiro
authors.initials: C
authors.lastname: Kojima
mesh_terms: D020029:Base Pairing; D006860:Hydrogen Bonding; D008024:Ligands; D008958:Models, Molecular; D009287:Naphthyridines / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D015363:Quinolones / Q000737:chemistry*; D012996:Solutions; D018911:Trinucleotide Repeats
chemical_list: C520187:(7-methylnaphthyridin-2-ylcarbmoylethyl)(8-azaquinolonecarbamoyl)amine; D008024:Ligands; D009287:Naphthyridines; D015363:Quinolones; D012996:Solutions