Not so crystal clear: the structure of the human telomere G-quadruplex in solution differs from that present in a crystal.

ABSTRACT: The structure of human telomere DNA is of intense interest because of its role in the biology of both cancer and aging. The sequence [5'-AGGG(TTAGGG)3] has been used as a model for telomere DNA in both NMR and X-ray crystallographic studies, the results of which show dramatically different structures. In Na+ solution, NMR revealed an antiparallel G-quadruplex structure that featured both diagonal and lateral TTA loops. Crystallographic studies in the presence of K+ revealed a flattened, propeller-shaped structure featuring a parallel-stranded G-quadruplex with symmetrical external TTA loops. We report the results of biophysical experiments in solution and computational studies that are inconsistent with the reported crystal structure, indicating that a different structure exists in K+ solu

SUBMITTER: Li J 

PROVIDER: S-EPMC1187823 | biostudies-literature | 2005

REPOSITORIES: biostudies-literature