title: X-ray analyses of two DNA dodecamers containing N4-methoxy-cytosine paired with adenine or guanine.
abstract: To investigate mismatch of base-pairings in relation to mutagenesis by oxyamines, crystal structures of two DNA dodecamers with the sequence d(CGCZAA TTmo4CGCG) (Z = A or G), containing N4-methoxy-cytosine (mo4C), have been determined by X-ray analysis. These dodecamers essentially form right-handed B-form duplexes, respectively. In the dodecamer with Z = A, the two mo4C residues are adapted in imino form with the anti methoxyl group to form pairs with A on the opposite strand in a manner of Watson-Crick fashion. While in the dodecamer with Z = G, one mo4C in amino form with the anti methoxyl group forms a normal Watson-Crick pair with G, but the other one in imino form with syn methoxyl conformation wobbles with G. Based on these results, possible mutation mechanism has been proposed.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
authors.forename: M T
authors.initials: MT
authors.lastname: Hossain
authors.forename: T
authors.initials: T
authors.lastname: Hikima
authors.forename: M
authors.initials: M
authors.lastname: Tsunoda
authors.forename: T
authors.initials: T
authors.lastname: Chatake
authors.forename: Y
authors.initials: Y
authors.lastname: Ueno
authors.forename: A
authors.initials: A
authors.lastname: Matsuda
authors.forename: A
authors.initials: A
authors.lastname: Takénaka
mesh_terms: D000225:Adenine / Q000737:chemistry; D020137:Base Pair Mismatch; D001483:Base Sequence; D018360:Crystallography, X-Ray; D003596:Cytosine / Q000031:analogs & derivatives* / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D006147:Guanine / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D009838:Oligodeoxyribonucleotides; C036689:N(4)-methoxycytosine; D006147:Guanine; D003596:Cytosine; D004247:DNA; D000225:Adenine