View source for 3ibk


==Crystal structure of a telomeric RNA quadruplex==
<StructureSection load='3ibk' size='340' side='right'caption='[[3ibk]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ibk]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3IBK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3IBK 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=5BU:5-BROMO-URIDINE-5-MONOPHOSPHATE'>5BU</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</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=3ibk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ibk OCA], [https://pdbe.org/3ibk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ibk RCSB], [https://www.ebi.ac.uk/pdbsum/3ibk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ibk ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
DNA telomeric repeats in mammalian cells are transcribed to guanine-rich RNA sequences, which adopt parallel-stranded G-quadruplexes with a propeller-like fold. The successful crystallization and structure analysis of a bimolecular human telomeric RNA G-quadruplex, folded into the same crystalline environment as an equivalent DNA oligonucleotide sequence, is reported here. The structural basis of the increased stability of RNA telomeric quadruplexes over DNA ones and their preference for parallel topologies is described here. Our findings suggest that the 2'-OH hydroxyl groups in the RNA quadruplex play a significant role in redefining hydration structure in the grooves and the hydrogen bonding networks. The preference for specific nucleotides to populate the C3'-endo sugar pucker domain is accommodated by alterations in the phosphate backbone, which leads to greater stability through enhanced hydrogen bonding networks. Molecular dynamics simulations on the DNA and RNA quadruplexes are consistent with these findings. The computations, based on the native crystal structure, provide an explanation for RNA G-quadruplex ligand binding selectivity for a group of naphthalene diimide ligands as compared to the DNA G-quadruplex.

A crystallographic and modelling study of a human telomeric RNA (TERRA) quadruplex.,Collie GW, Haider SM, Neidle S, Parkinson GN Nucleic Acids Res. 2010 Apr 22. PMID:20413582<ref>PMID:20413582</ref>

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