N6-methoxyadenine in damaged DNA has two faces in property of Watson-Crick base pairing.
In order to investigate mutation mechanism with oxyamine, two DNA dodecamers containing 2'-deoxy-N6-methoxyadenosine have been synthesized and their crystal structures have been determined. The dodecamers are associated in B form duplexes. The methoxy groups attached to the adenine bases do not affect the DNA conformation significantly. Electron densities clearly show that N6-methoxyadenine moiety forms Watson-Crick type pairing with both, thymine and cytosine bases. Such two faces in pairing are the origin of pyrimidine transition mutation.
Chatake
T
T
Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Ono
A
A
Ueno
Y
Y
Matsuda
A
A
Takénaka
A
A
D000225:Adenine / Q000031:analogs & derivatives* / Q000032:analysis; D020029:Base Pairing; D001483:Base Sequence; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D004583:Electrons; D008957:Models, Genetic; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*
D009838:Oligodeoxyribonucleotides; C073276:N(6)-methoxyadenine; D004247:DNA; D000225:Adenine