1d8g: Difference between revisions

Revision as of 13:14, 21 February 2008

ULTRAHIGH RESOLUTION CRYSTAL STRUCTURE OF B-DNA DECAMER D(CCAGTACTGG)

OverviewOverview

The affinity and specificity of a ligand for its DNA site is a function of the conformational changes between the isolated and complexed states. Although the structures of a hydroxypyrrole-imidazole-pyrrole polyamide dimer with 5'-CCAGTACTGG-3' and the trp repressor recognizing the sequence 5'-GTACT-3' are known, the baseline conformation of the DNA site would contribute to our understanding of DNA recognition by these ligands. The 0.74 A resolution structure of a B-DNA double helix, 5'-CCAGTACTGG-3', has been determined by X-ray crystallography. Six of the nine phosphates, two of four bound calcium ions and networks of water molecules hydrating the oligonucleotide have alternate conformations. By contrast, nine of the ten bases have a single, unique conformation with hydrogen atoms visible in most cases. The polyamide molecules alter the geometry of the phosphodiester backbone, and the water molecules mediating contacts in the trp repressor/operator complex are conserved in the unliganded DNA. Furthermore, the multiple conformational states, ions and hydration revealed by this ultrahigh resolution structure of a B-form oligonucleotide are potentially general considerations for understanding DNA-binding affinity and specificity by ligands.

About this StructureAbout this Structure

1D8G is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Conformational flexibility of B-DNA at 0.74 A resolution: d(CCAGTACTGG)(2)., Kielkopf CL, Ding S, Kuhn P, Rees DC, J Mol Biol. 2000 Feb 25;296(3):787-801. PMID:10677281

Page seeded by OCA on Thu Feb 21 12:14:04 2008

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OCA

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-[[Image:1d8g.gif|left|200px]]<br /><applet load="1d8g" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1d8g.gif|left|200px]]<br /><applet load="1d8g" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1d8g, resolution 0.74&Aring;" />
 '''ULTRAHIGH RESOLUTION CRYSTAL STRUCTURE OF B-DNA DECAMER D(CCAGTACTGG)'''<br />
 ==Overview==
-The affinity and specificity of a ligand for its DNA site is a function of, the conformational changes between the isolated and complexed states., Although the structures of a hydroxypyrrole-imidazole-pyrrole polyamide, dimer with 5'-CCAGTACTGG-3' and the trp repressor recognizing the sequence, 5'-GTACT-3' are known, the baseline conformation of the DNA site would, contribute to our understanding of DNA recognition by these ligands. The, 0.74 A resolution structure of a B-DNA double helix, 5'-CCAGTACTGG-3', has, been determined by X-ray crystallography. Six of the nine phosphates, two, of four bound calcium ions and networks of water molecules hydrating the, oligonucleotide have alternate conformations. By contrast, nine of the ten, bases have a single, unique conformation with hydrogen atoms visible in, most cases. The polyamide molecules alter the geometry of the, phosphodiester backbone, and the water molecules mediating contacts in the, trp repressor/operator complex are conserved in the unliganded DNA., Furthermore, the multiple conformational states, ions and hydration, revealed by this ultrahigh resolution structure of a B-form, oligonucleotide are potentially general considerations for understanding, DNA-binding affinity and specificity by ligands.
+The affinity and specificity of a ligand for its DNA site is a function of the conformational changes between the isolated and complexed states. Although the structures of a hydroxypyrrole-imidazole-pyrrole polyamide dimer with 5'-CCAGTACTGG-3' and the trp repressor recognizing the sequence 5'-GTACT-3' are known, the baseline conformation of the DNA site would contribute to our understanding of DNA recognition by these ligands. The 0.74 A resolution structure of a B-DNA double helix, 5'-CCAGTACTGG-3', has been determined by X-ray crystallography. Six of the nine phosphates, two of four bound calcium ions and networks of water molecules hydrating the oligonucleotide have alternate conformations. By contrast, nine of the ten bases have a single, unique conformation with hydrogen atoms visible in most cases. The polyamide molecules alter the geometry of the phosphodiester backbone, and the water molecules mediating contacts in the trp repressor/operator complex are conserved in the unliganded DNA. Furthermore, the multiple conformational states, ions and hydration revealed by this ultrahigh resolution structure of a B-form oligonucleotide are potentially general considerations for understanding DNA-binding affinity and specificity by ligands.
 ==About this Structure==
-D8G is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1D8G OCA].
+D8G is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D8G OCA].
 ==Reference==
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 [[Category: ultrahigh resolution]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 02:45:25 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:14:04 2008''