A novel intramolecular G-quartet-containing fold of single-stranded d(GT)(8) and d(GT)(16) oligonucleotides.
Human genome is shown to be enriched with (GT)(n) stretches of lengths from 8 to 20 dinucleotides. Low temperature (T< or =10 degrees C) conformations of d(GT)(n) oligonucleotides (n=7, 8, 12, 16, 20) were studied by means of circular dichroism (CD), thermal melting, ethidium bromide (EtBr) probing and single nucleotide substitutions. Rotational relaxation times for EtBr:d(GT)(n) complexes confirmed a monomolecular state of the oligonucleotides. CD spectra indicated involvement of all guanines of d(GT)(8) and d(GT)(16) in G-quartets, while dT(GT)(7), d(GT)(12) and d(GT)(20) were shown to be only partially ordered. The schemes of the d(GT)(8) and d(GT)(16) folds are suggested.
Kaluzhny
Dmitry
D
Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, Moscow, Russia. uzhny@mail.ru
Shchyolkina
Anna
A
Livshits
Michael
M
Lysov
Yury
Y
Borisova
Olga
O
D002942:Circular Dichroism; D004277:DNA, Single-Stranded / Q000737:chemistry*; D004996:Ethidium / Q000737:chemistry; D054856:G-Quadruplexes; D006801:Humans; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides / Q000737:chemistry*; D013816:Thermodynamics; D044366:Transition Temperature
D004277:DNA, Single-Stranded; D011089:Polydeoxyribonucleotides; C017650:polydeoxy(guanine-thymine) nucleotide; D004996:Ethidium