Download MendeleyStructure of Human Telomeric DNA in Crowded Solution
Heddi, B., Phan, A.T.(2011) J Am Chem Soc
- PubMed: 21548653
- DOI: https://doi.org/10.1021/ja200786q
- Primary Citation of Related Structures:
2LD8 - PubMed Abstract:
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.
Organizational Affiliation:
School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
