title: Crystallographic studies on damaged DNAs: III. N(4)-methoxycytosine can form both Watson-Crick type and wobbled base pairs in a B-form duplex.
abstract: To investigate the mutation mechanism of purine transition in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCGAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and its crystal structure determined. Two dodecamers form a B-form duplex. Electron density maps clearly show that one of the two mo(4)C residues forms a pair with a guanine residue of the opposite strand, the geometry being the canonical Watson-Crick type, and that the other mo(4)C residue forms a wobble pair with the opposite guanine residue. These two pairings are ascribed to the tautomerization of the methoxylated cytosine moieties between the amino and imino forms.
authors: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
authors: M T
authors: MT
authors: Hossain
authors: T
authors: T
authors: Chatake
authors: T
authors: T
authors: Hikima
authors: M
authors: M
authors: Tsunoda
authors: T
authors: T
authors: Sunami
authors: Y
authors: Y
authors: Ueno
authors: A
authors: A
authors: Matsuda
authors: A
authors: A
authors: Takénaka
mesh_terms: D020029:Base Pairing; D018360:Crystallography, X-Ray; D003596:Cytosine / Q000031:analogs & derivatives* / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D008958:Models, Molecular; D055672:Static Electricity
chemical_list: C036689:N(4)-methoxycytosine; D003596:Cytosine; D004247:DNA