title: Effect of 1-methyladenine on double-helical DNA structures.
abstract: Methylation at the N1 site of adenine leads to the formation of cytotoxic 1-methyladenine (m1A). Since the N1 site of adenine is involved in the hydrogen bonding of T.A and A.T Watson-Crick base pairs, it is expected that the pairing interactions will be disrupted upon 1-methylation. In this study, high-resolution NMR investigations were performed to determine the effect of m1A on double-helical DNA structures. Interestingly, instead of disrupting hydrogen bonding, we found that 1-methylation altered the T.A Watson-Crick base pair to T(anti).m1A(syn) Hoogsteen base pair, providing insights into the observed differences in AlkB-repair efficiency between dsDNA and ssDNA.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
authors.forename: Yingqian
authors.initials: Y
authors.lastname: Zhan
authors.forename: Dickson
authors.initials: D
authors.lastname: Fenn
authors.forename: Lai Man
authors.initials: LM
authors.lastname: Chi
authors.forename: Sik Lok
authors.initials: SL
authors.lastname: Lam
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry; D020029:Base Pairing; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D019175:DNA Methylation; D006860:Hydrogen Bonding; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation
chemical_list: C008407:1-methyladenine; D004247:DNA; D000225:Adenine