Crystallographic studies on damaged DNAs: III. N(4)-methoxycytosine can form both Watson-Crick type and wobbled base pairs in a B-form duplex

M T Hossain; T Chatake; T Hikima; M Tsunoda; T Sunami; Y Ueno; A Matsuda; A Takénaka

doi:10.1093/oxfordjournals.jbchem.a002967

Crystallographic studies on damaged DNAs: III. N(4)-methoxycytosine can form both Watson-Crick type and wobbled base pairs in a B-form duplex

J Biochem. 2001 Jul;130(1):9-12. doi: 10.1093/oxfordjournals.jbchem.a002967.

Authors

M T Hossain¹, T Chatake, T Hikima, M Tsunoda, T Sunami, Y Ueno, A Matsuda, A Takénaka

Affiliation

¹ Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.

PMID: 11432773
DOI: 10.1093/oxfordjournals.jbchem.a002967

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Base Pairing*
Crystallography, X-Ray
Cytosine / analogs & derivatives*
Cytosine / chemistry*
DNA / chemistry*
DNA Damage*
Models, Molecular
Static Electricity

Substances

N(4)-methoxycytosine
Cytosine
DNA