title: A novel intramolecular G-quartet-containing fold of single-stranded d(GT)(8) and d(GT)(16) oligonucleotides.
abstract: 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.
authors.affiliation: Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, Moscow, Russia. uzhny@mail.ru
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kaluzhny
authors.forename: Anna
authors.initials: A
authors.lastname: Shchyolkina
authors.forename: Michael
authors.initials: M
authors.lastname: Livshits
authors.forename: Yury
authors.initials: Y
authors.lastname: Lysov
authors.forename: Olga
authors.initials: O
authors.lastname: Borisova
mesh_terms: 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
chemical_list: D004277:DNA, Single-Stranded; D011089:Polydeoxyribonucleotides; C017650:polydeoxy(guanine-thymine) nucleotide; D004996:Ethidium