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Publication Abstract from PubMed

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.

Crystallographic studies on damaged DNAs: III. N(4)-methoxycytosine can form both Watson-Crick type and wobbled base pairs in a B-form duplex.,Hossain MT, Chatake T, Hikima T, Tsunoda M, Sunami T, Ueno Y, Matsuda A, Takenaka A J Biochem. 2001 Jul;130(1):9-12. PMID:11432773^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.