- Crystallographic studies on damaged DNAs. II. N(6)-methoxyadenine can present two alternate faces for Watson-Crick base-pairing, leading to pyrimidine transition mutagenesis. Chatake, T., Hikima, T., Ono, A., Ueno, Y., Matsuda, A., Takénaka, A. J. Mol. Biol. (1999)