1kf1
From Proteopedia
(New page: 200px<br /><applet load="1kf1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kf1, resolution 2.1Å" /> '''Structure and Packing...) |
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| - | [[Image:1kf1.gif|left|200px]]<br /><applet load="1kf1" size=" | + | [[Image:1kf1.gif|left|200px]]<br /><applet load="1kf1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kf1, resolution 2.1Å" /> | caption="1kf1, resolution 2.1Å" /> | ||
'''Structure and Packing of Human Telomeric DNA'''<br /> | '''Structure and Packing of Human Telomeric DNA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Telomeric ends of chromosomes, which comprise noncoding repeat sequences | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1KF1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with K as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1KF1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=K:'>K</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KF1 OCA]. |
==Reference== | ==Reference== | ||
Crystal structure of parallel quadruplexes from human telomeric DNA., Parkinson GN, Lee MP, Neidle S, Nature. 2002 Jun 20;417(6891):876-80. Epub 2002 May 26. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12050675 12050675] | Crystal structure of parallel quadruplexes from human telomeric DNA., Parkinson GN, Lee MP, Neidle S, Nature. 2002 Jun 20;417(6891):876-80. Epub 2002 May 26. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12050675 12050675] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Lee, M | + | [[Category: Lee, M P.H.]] |
[[Category: Neidle, S.]] | [[Category: Neidle, S.]] | ||
| - | [[Category: Parkinson, G | + | [[Category: Parkinson, G N.]] |
[[Category: K]] | [[Category: K]] | ||
[[Category: double chain reversal loop]] | [[Category: double chain reversal loop]] | ||
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[[Category: quadruplex dna]] | [[Category: quadruplex dna]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:23 2008'' |
Revision as of 11:33, 21 February 2008
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Structure and Packing of Human Telomeric DNA
Overview
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.
About this Structure
1KF1 is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of parallel quadruplexes from human telomeric DNA., Parkinson GN, Lee MP, Neidle S, Nature. 2002 Jun 20;417(6891):876-80. Epub 2002 May 26. PMID:12050675
Page seeded by OCA on Thu Feb 21 13:33:23 2008
