title: Structural study of DNA duplex containing an N-(2-deoxy-beta-D-erythro-pentofuranosyl) formamide frameshift by NMR and restrained molecular dynamics.
abstract: The presence of an N-(2-deoxy-beta-D-erythro-pentofuranosyl) formamide (F) residue, a ring fragmentation product of thymine, in a frameshift context in the sequence 5'-d-(AGGACCACG)*d(CGTGGFTCCT) has been studied by 1H and 31P nuclear magnetic resonance (NMR) and molecular dynamics. Two-dimensional NMR studies show that the formamide residue, whether the cis or trans isomer, is rotated out of the helix and that the bases on either side of the formamide residue in the sequence, G14 and T16, are stacked over each other in a way similar to normal B-DNA. The cis and trans isomers were observed in the ratio 3:2 in solution. Information extracted from 31P NMR data reveal a modification of the phosphodiester backbone conformation at the extrahelical site, which is also observed during the molecular dynamics simulations.
authors.affiliation: CEA, Département de Biologie Joliot Curie, Service de Biochimie et de Génétique Moléculaire, Bat 144, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Maufrais
authors.forename: G V
authors.initials: GV
authors.lastname: Fazakerley
authors.forename: J
authors.initials: J
authors.lastname: Cadet
authors.forename: Y
authors.initials: Y
authors.lastname: Boulard
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004249:DNA Damage; D005559:Formamides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry* / Q000235:genetics; D011522:Protons; D012266:Ribose / Q000031:analogs & derivatives / Q000737:chemistry*; D013696:Temperature
chemical_list: D005559:Formamides; C481051:N-(2-deoxypentofuranosyl)formamide; D009692:Nucleic Acid Heteroduplexes; D011522:Protons; C031066:formamide; D012266:Ribose; D004247:DNA