View source for 3cco


==Structural adaptation and conservation in quadruplex-drug recognition==
<StructureSection load='3cco' size='340' side='right'caption='[[3cco]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3cco]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CCO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3CCO FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NII:2,7-BIS[3-(DIMETHYLAMINO)PROPYL]-4,9-BIS[(3-HYDROXYPROPYL)AMINO]BENZO[LMN][3,8]PHENANTHROLINE-1,3,6,8(2H,7H)-TETRONE'>NII</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3cco FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3cco OCA], [https://pdbe.org/3cco PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3cco RCSB], [https://www.ebi.ac.uk/pdbsum/3cco PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3cco ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Knowledge of the biologically relevant topology is critical for the design of drugs targeting quadruplex nucleic acids. We report here crystal structures of a G-quadruplex-selective ligand complexed with two human telomeric DNA quadruplexes. The intramolecular quadruplex sequence d[TAGGG(TTAGGG)(3)] and the bimolecular quadruplex sequence d(TAGGGTTAGGGT) were co-crystallized with a tetra-substituted naphthalene diimide quadruplex-binding ligand. The structures were solved and refined to 2.10- and 2.20-A resolution, respectively, revealing that the quadruplex topology in both structures is unchanged by the addition of the ligands, retaining a parallel-stranded arrangement with external double-chain-reversal propeller loops. The parallel topology results in accessible external 5' and 3' planar G-tetrad surfaces for ligand stacking. This also enables significant ligand-induced conformational changes in several TTA propeller loops to take place such that the loops themselves are able to accommodate bound drug molecules without affecting the parallel quadruplex topology, by stacking on the external TTA connecting loop nucleotides. Ligands are bound into the external TTA loop nucleotides and stack onto G-tetrad surfaces. These crystal structures provide a framework for further ligand development of the naphthalene diimide series to enhance selectivity and affinity.

Topology conservation and loop flexibility in quadruplex-drug recognition: crystal structures of inter- and intramolecular telomeric DNA quadruplex-drug complexes.,Parkinson GN, Cuenca F, Neidle S J Mol Biol. 2008 Sep 19;381(5):1145-56. Epub 2008 Jun 17. PMID:18619463<ref>PMID:18619463</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3cco" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Neidle S]]
[[Category: Parkinson GN]]