6n4g

<StructureSection load='6n4g' size='340' side='right' caption='[[6n4g]], [[Resolution|resolution]] 1.40&Aring;' scene=''>

<table><tr><td colspan='2'>[[6n4g]] is a 2 chain structure. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=6mc5 6mc5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6N4G OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6N4G FirstGlance]. <br>

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

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[6mc2|6mc2]], [[6mc3|6mc3]], [[6mc4|6mc4]]</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=6n4g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n4g OCA], [http://pdbe.org/6n4g PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6n4g RCSB], [http://www.ebi.ac.uk/pdbsum/6n4g PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6n4g ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

DNA can adopt many structures beyond the Watson-Crick duplex. However, the bounds of DNA structural diversity and how these structures might regulate biological processes is only beginning to be understood. Here, we describe the 1.05 A resolution crystal structure of a DNA oligonucleotide that self-associates to form a non-G-quadruplex fold-back structure. Distinct from previously described fold-back quadruplexes, two-fold-back dimers interact through noncanonical and Watson-Crick interactions to form a tetrameric assembly. These interactions include a hexad base pairing arrangement from two C-G-G base triples. The assembly is dependent on divalent cations, and the interface between the dimeric units creates a cavity in which a cation resides. This structure provides new sequence and structural contexts for the formation of fold-back quadruplexes, further highlighting the potential biological importance of this type of noncanonical DNA structure. This structure may also serve as the basis for designing new types of DNA nanoarchitectures or cation sensors based on the strong divalent cation dependence.

Crystal Structure of a Tetrameric DNA Fold-Back Quadruplex.,Chu B, Zhang D, Hwang W, Paukstelis PJ J Am Chem Soc. 2018 Nov 13. doi: 10.1021/jacs.8b10153. PMID:30384604<ref>PMID:30384604</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 6n4g" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Chu, B]]

[[Category: Paukstelis, P J]]

[[Category: Dna]]

[[Category: Fold-back]]

[[Category: Quadruplex]]