6jkn

<table><tr><td colspan='2'>[[6jkn]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6JKN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6JKN FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=BGM:8-BROMO-2-DEOXYGUANOSINE-5-MONOPHOSPHATE'>BGM</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6jkn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6jkn OCA], [http://pdbe.org/6jkn PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6jkn RCSB], [http://www.ebi.ac.uk/pdbsum/6jkn PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6jkn ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

Human telomeric guanine-rich DNA, which could adopt different G-quadruplex structures, plays important roles in protecting the cell from recombination and degradation. Although many of these structures were determined, the chair-type G-quadruplex structure remains elusive. Here, we present a crystal structure of the G-quadruplex composed of the human telomeric sequence d[GGGTTAGG8GTTAGGGTTAGG20G] with two dG to 8Br-dG substitutions at positions 8 and 20 with syn conformation in the K+ solution. It forms a novel three-layer chair-type G-quadruplex with two linking trinucleotide loops. Particularly, T5 and T17 are coplanar with two water molecules stacking on the G-tetrad layer in a sandwich-like mode through a coordinating K+ ion and an A6*A18 base pair. While a twisted Hoogsteen A12*T10 base pair caps on the top of G-tetrad core. The three linking TTA loops are edgewise and each DNA strand has two antiparallel adjacent strands. Our findings contribute to a deeper understanding and highlight the unique roles of loop and water molecule in the folding of the G-quadruplex.

The crystal structure of an antiparallel chair-type G-quadruplex formed by Bromo-substituted human telomeric DNA.,Geng Y, Liu C, Zhou B, Cai Q, Miao H, Shi X, Xu N, You Y, Fung CP, Din RU, Zhu G Nucleic Acids Res. 2019 Apr 8. pii: 5430838. doi: 10.1093/nar/gkz221. PMID:30957851<ref>PMID:30957851</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 6jkn" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Cai, Q]]

[[Category: Geng, Y]]

[[Category: Liu, C]]

[[Category: Zhu, G]]

[[Category: G-quadruplex]]