VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Tetramolecular DNA quadruplexes in solution : insights into structural diversity and cation movement
    Šket, Primož, 1977- ; Plavec, Janez
    The present study expands the notion that the simple oligonucleotide sequence d(TG4T) in solution forms a tetramolecular G-quadruplex having a parallel orientation of the four strands and four ... G-quartets with all of the residues in the anti orientation. NMR experiments have revealed the equilibrium of two monomeric forms with a ratio between 85:15 and 70:30 in the presence of K+, Na+, and 15NH4+ ions. The major form consists of four G-quartets, whereas the minor form exhibits an additional T-quartet at the 5' end. An analogous oligonucleotide with U at the 5' end adopts a dimeric structure of G-quadruplex units in the presence of K+ and 15NH4+ cations but not in the presence of Na+ ions, where monomeric forms are present. Three 15NH4+ ion binding sites between the four G-quartets within the major monomeric form havebeen identified, while an additional 15NH4+ ion binding site between the G- and T-quartets at the 5' end of the minor form has been established. The dimeric d[(UG4T)4]2 G-quadruplex exhibits eight 15NH4+ ion binding sites, two of them between the U- and G-quartets. 15NH4+ ions have been shown to move faster between the interior of the tetramolecular structures and the bulk solution in comparison with the monomolecular and bimolecular G-quadruplexes. However, cation movement is slowed by the presence of a T-quartet at the 5' end.
    Vir: Journal of the American Chemical Society : JACS. - ISSN 0002-7863 (Vol. 132, no. 36, 2010, str. 12724-12732)
    Vrsta gradiva - članek, sestavni del
    Leto - 2010
    Jezik - angleški
    COBISS.SI-ID - 4487962

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