Silver ion unusually stabilizes the structure of a parallel-motif DNA triplex.
A simple and easy method for stabilizing DNA triplexes using Ag(+) is reported. A silver ion displaces the N3 proton of cytosine in Hoogsteen base-pairing to form the base triplet CG.CAg(+). By the addition of an equimolar amount of Ag(+), the third-strand 15-mer sequence containing five cytosines was stabilized by approximately 30 degrees C in melting temperature at pH 7. The triplex structure was stable even under weakly basic conditions.
Ihara
Toshihiro
T
Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. toshi@chem.kumamoto-u.ac.jp
Ishii
Tatsuaki
T
Araki
Norie
N
Wilson
Anthony W
AW
Jyo
Akinori
A
D020029:Base Pairing; D001665:Binding Sites; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012834:Silver / Q000737:chemistry*; D044366:Transition Temperature
C051802:triplex DNA; D012834:Silver; D003596:Cytosine; D004247:DNA