[Intramolecular G-quadruplexes from microsatellite d(GT)12 sequence in the presence of K+].
Polymorphic d(GT)n microsatellite sequences are known to drastically affect genes expression. By use of CD spectroscopy, UV melting, fluorescence polarization of EtBr probe and FRET, we detected formation of a new fold with three G-quartets by d(GT)12 oligonucleotide in 0.01 M Na phosphate buffer, pH 8.0, in the presence 0.1 M KCl. Monomolecular type of the structure was verified with measurements of rotational relaxation time (p = 28 +/- 0.5 ns) of EtBr:d(GT)12 complex. CD spectra supported G-quartets formation. A distance between FITC, covalently attached to 5'-end of d(GT)12, and intercalated EtBr molecule was estimated using FRET (R < or =17 A). These data are in agreement with the proposed self folding of d(GT)12.
D N
DN
Kaliuzhnyĭ
F S
FS
Bondarev
A K
AK
Shchelkina
M A
MA
Livshits
O F
OF
Borisova
D002414:Cations, Monovalent; D002942:Circular Dichroism; D018895:Microsatellite Repeats; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*
D002414:Cations, Monovalent; D009838:Oligodeoxyribonucleotides; D011188:Potassium