Format

Send to

Choose Destination
FEBS J. 2007 Jul;274(14):3545-3556. doi: 10.1111/j.1742-4658.2007.05881.x. Epub 2007 Jun 11.

Structure of a human telomeric DNA sequence stabilized by 8-bromoguanosine substitutions, as determined by NMR in a K+ solution.

Author information

1
Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, JapanGraduate School of Sciences, Kyoto University, Japan,RIKEN, Yokohama, Japan,PRESTO, Yokohama, Japan.

Abstract

The structure of human telomeric DNA is controversial; it depends upon the sequence contexts and the methodologies used to determine it. The solution structure in the presence of K(+) is particularly interesting, but the structure is yet to be elucidated, due to possible conformational heterogeneity. Here, a unique strategy is applied to stabilize one such structure in a K(+) solution by substituting guanosines with 8-bromoguanosines at proper positions. The resulting spectra are cleaner and led to determination of the structure at a high atomic resolution. This demonstrates that the application of 8-bromoguanosine is a powerful tool to overcome the difficulty of nucleic acid structure determination arising from conformational heterogeneity. The obtained structure is a mixed-parallel/antiparallel quadruplex. The structure of telomeric DNA was recently reported in another study, in which stabilization was brought about by mutation and resultant additional interactions [Luu KN, Phan AT, Kuryavyi V, Lacroix L & Patel DJ (2006) Structure of the human telomere in K(+) solution: an intramolecular (3+1) G-quadruplex scaffold. J Am Chem Soc 128, 9963-9970]. The structure of the guanine tracts was similar between the two. However, a difference was seen for loops connecting guanine tracts, which may play a role in the higher order arrangement of telomeres. Our structure can be utilized to design a small molecule which stabilizes the quadruplex. This type of molecule is supposed to inhibit a telomerase and thus is expected to be a candidate anticancer drug.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center