Arrangements of human telomere DNA quadruplex in physiologically relevant K+ solutions.

ABSTRACT: The arrangement of the human telomeric quadruplex in physiologically relevant conditions has not yet been unambiguously determined. Our spectroscopic results suggest that the core quadruplex sequence G(3)(TTAG(3))(3) forms an antiparallel quadruplex of the same basket type in solution containing either K(+) or Na(+) ions. Analogous sequences extended by flanking nucleotides form a mixture of the antiparallel and hybrid (3 + 1) quadruplexes in K(+)-containing solutions. We, however, show that long telomeric DNA behaves in the same way as the basic G(3)(TTAG(3))(3) motif. Both G(3)(TTAG(3))(3) and long telomeric DNA are also able to adopt the (3 + 1) quadruplex structure: Molecular crowding conditions, simulated here by ethanol, induced a slow transition of the K(+)-stabilized quadruplex int

SUBMITTER: Renciuk D 

PROVIDER: S-EPMC2770667 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature