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Publication Abstract from PubMed

G-quadruplex structures formed by DNA at the human telomeres are attractive anticancer targets. Human telomeric sequences can adopt a diverse range of intramolecular G-quadruplex conformations: a parallel-stranded conformation was observed in the crystalline state, while at least four other forms were seen in K(+) solution, raising the question of which conformation is favored in crowded cellular environment. Here, we report the first NMR structure of a human telomeric G-quadruplex in crowded solution. We show that four different G-quadruplex conformations are converted to a propeller-type parallel-stranded G-quadruplex in K(+)-containing crowded solution due to water depletion. This study also reveals the formation of a new higher-order G-quadruplex structure under molecular crowding conditions. Our molecular dynamics simulations of solvent distribution provide insights at molecular level on the formation of parallel-stranded G-quadruplex in environment depleted of water. These results regarding human telomeric DNA can be extended to oncogenic promoters and other genomic G-rich sequences.

Structure of Human Telomeric DNA in Crowded Solution.,Heddi B, Phan AT J Am Chem Soc. 2011 Jun 29;133(25):9824-9833. Epub 2011 Jun 6. PMID:21548653^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.