Extreme conformational diversity in human telomeric DNA.

ABSTRACT: DNA with tandem repeats of guanines folds into G-quadruplexes made of a stack of G-quartets. In vitro, G-quadruplex formation inhibits telomere extension, and POT1 binding to the single-stranded telomeric DNA enhances telomerase activity by disrupting the G-quadruplex structure, highlighting the potential importance of the G-quadruplex structure in regulating telomere length in vivo. We have used single-molecule spectroscopy to probe the dynamics of human telomeric DNA. Three conformations were observed in potassium solution, one unfolded and two folded, and each conformation could be further divided into two species, long-lived and short-lived, based on lifetimes of minutes vs. seconds. Vesicle encapsulation studies suggest that the total of six states detected here is intrinsic to the DN

SUBMITTER: Lee JY 

PROVIDER: S-EPMC1316883 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature