View source for 5lqg


==A two-quartet G-quadruplex formed by human telomere in KCl solution at neutral pH==
<StructureSection load='5lqg' size='340' side='right'caption='[[5lqg]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5lqg]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5LQG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5LQG FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=5lqg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5lqg OCA], [https://pdbe.org/5lqg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5lqg RCSB], [https://www.ebi.ac.uk/pdbsum/5lqg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5lqg ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
A four-repeat human telomere DNA sequence without the 3'-end guanine, d[TAGGG(TTAGGG)2 TTAGG] (htel1-DeltaG23) has been found to adopt two distinct two G-quartet antiparallel basket-type G-quadruplexes, TD and KDH(+) in presence of KCl. NMR, CD, and UV spectroscopy have demonstrated that topology of KDH(+) form is distinctive with unique protonated T18A20(+) G5 base triple and other capping structural elements that provide novel insight into structural polymorphism and heterogeneity of G-quadruplexes in general. Specific stacking interactions amongst two G-quartets flanking base triples and base pairs in TD and KDH(+) forms are reflected in 10 K higher thermal stability of KDH(+) . Populations of TD and KDH(+) forms are controlled by pH. The (de)protonation of A20 is the key for pH driven structural transformation of htel1-DeltaG23. Reversibility offers possibilities for its utilization as a conformational switch within different compartments of living cell enabling specific ligand and protein interactions.

Reversible pH Switch of Two-Quartet G-Quadruplexes Formed by Human Telomere.,Galer P, Wang B, Sket P, Plavec J Angew Chem Int Ed Engl. 2016 Feb 5;55(6):1993-7. doi: 10.1002/anie.201507569., Epub 2016 Jan 6. PMID:26836334<ref>PMID:26836334</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Galer P]]
[[Category: Plavec J]]
[[Category: Sket P]]
[[Category: Wang B]]