Poly(amino2dA-dT) isomerizes into the unusual X-DNA double helix at physiological conditions inducing Z-DNA in poly (dG-methyl5dC)
Jazyk angličtina Země Anglie, Velká Británie Médium print
Typ dokumentu časopisecké články
- MeSH
- cirkulární dichroismus MeSH
- DNA * MeSH
- isomerie MeSH
- konformace nukleové kyseliny MeSH
- magnetická rezonanční spektroskopie MeSH
- polydeoxyribonukleotidy * MeSH
- viry genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA * MeSH
- poly(amino(2)dA-dT) MeSH Prohlížeč
- polydeoxyribonukleotidy * MeSH
It is demonstrated that a two-state conformational isomerization is induced in the poly(amino2-dA-dT) duplex by submillimolar concentrations of divalent magnesium cations in low-salt aqueous solution. The isomerization is fast and has a low degree of cooperativity. The resulting conformer is the unusual X-DNA double helix originally observed with poly(dA-dT) at very high concentrations of CsF. Interestingly, the X form is induced in poly(amino2dA-dT) under the physiological conditions when poly(dG-methyl5dC) assumes Z-DNA. The same conditions of stabilization are presumably connected with the fact, observed in previous phosphorus NMR studies, that Z- and X-DNA have similar polydinucleotide backbone architectures. Results presented in this work permit to specify base pair exocyclic groups responsible for the radically different conformational variability of the synthetic DNA molecules containing alternating purine-pyrimidine sequences of GC or AT base pairs.
Citace poskytuje Crossref.org
Circular dichroism and conformational polymorphism of DNA
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