1KF1

Structure and Packing of Human Telomeric DNA

Summary for 1KF1

• Entry DOI: 10.2210/pdb1kf1/pdb
• Descriptor: 5'-D(*AP*GP*GP*GP*TP*TP*AP*GP*GP*GP*TP*TP*AP*GP*GP*GP*TP*TP*AP*GP*GP*G)-3, POTASSIUM ION (3 entities in total)
• Functional Keywords: quadruplex dna, double chain reversal loop, human telomere sequence, g(anti).g(anti).g(anti), parallel stranded, dna
• Total number of polymer chains: 1
• Total formula weight: 7100.79

Authors

Parkinson, G.N.,Lee, M.P.H.,Neidle, S. (deposition date: 2001-11-19, release date: 2002-05-31, Last modification date: 2023-08-16)

Primary citation

Parkinson, G.N.,Lee, M.P.,Neidle, S.
Crystal structure of parallel quadruplexes from human telomeric DNA.
Nature, 417:876-880, 2002

PubMed Abstract: Telomeric ends of chromosomes, which comprise noncoding repeat sequences of guanine-rich DNA, are fundamental in protecting the cell from recombination and degradation. Disruption of telomere maintenance leads to eventual cell death, which can be exploited for therapeutic intervention in cancer. Telomeric DNA sequences can form four-stranded (quadruplex) structures, which may be involved in the structure of telomere ends. Here we describe the crystal structure of a quadruplex formed from four consecutive human telomeric DNA repeats and grown at a K(+) concentration that approximates its intracellular concentration. K(+) ions are observed in the structure. The folding and appearance of the DNA in this intramolecular quadruplex is fundamentally different from the published Na(+)-containing quadruplex structures. All four DNA strands are parallel, with the three linking trinucleotide loops positioned on the exterior of the quadruplex core, in a propeller-like arrangement. The adenine in each TTA linking trinucleotide loop is swung back so that it intercalates between the two thymines. This DNA structure suggests a straightforward path for telomere folding and unfolding, as well as ways in which it can recognize telomere-associated proteins.

PubMed: 12050675
DOI: 10.1038/nature755

Experimental method

X-RAY DIFFRACTION (2.1 Å)