View source for 4xw0


==Crystal structure of (GCCU(G-LNA)CCUGC)2 duplex==
<StructureSection load='4xw0' size='340' side='right'caption='[[4xw0]], [[Resolution|resolution]] 1.81&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xw0]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XW0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XW0 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]] 1.81&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LCG:[(1R,3R,4R,7S)-7-HYDROXY-3-(GUANIN-9-YL)-2,5-DIOXABICYCLO[2.2.1]HEPT-1-YL]METHYL+DIHYDROGEN+PHOSPHATE'>LCG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4xw0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xw0 OCA], [https://pdbe.org/4xw0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xw0 RCSB], [https://www.ebi.ac.uk/pdbsum/4xw0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xw0 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RNA transcripts that include expanded CCUG repeats are associated with myotonic dystrophy type 2. Crystal structures of two CCUG-containing oligomers show that the RNA strands associate into slipped duplexes that contain noncanonical C-U pairs that have apparently undergone tautomeric transition or protonation resulting in an unusual Watson-Crick-like pairing. The overhanging ends of the duplexes interact forming U-U pairs, which also show tautomerism. Duplexes consisting of CCUG repeats are thermodynamically less stable than the trinucleotide repeats involved in the TRED genetic disorders, but introducing LNA residues increases their stability and raises the melting temperature of the studied oligomers by approximately 10 degrees C, allowing detailed crystallographic studies. Quantum mechanical calculations were performed to test the possibility of the tautomeric transitions or protonation within the noncanonical pairs. The results indicate that tautomeric or ionic shifts of nucleobases can manifest themselves in biological systems, supplementing the canonical "rules of engagement."

Watson-Crick-like pairs in CCUG repeats: evidence for tautomeric shifts or protonation.,Rypniewski W, Banaszak K, Kulinski T, Kiliszek A RNA. 2016 Jan;22(1):22-31. doi: 10.1261/rna.052399.115. Epub 2015 Nov 5. PMID:26543073<ref>PMID:26543073</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xw0" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Banaszak K]]
[[Category: Kiliszek A]]
[[Category: Rypniewski W]]