6e8s

<table><tr><td colspan='2'>[[6e8s]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6E8S OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6E8S FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EKJ:4-[(3-{2-[(2-methoxyethyl)amino]-2-oxoethyl}-1,3-benzothiazol-3-ium-2-yl)methyl]-1-methylquinolin-1-ium'>EKJ</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=SPM:SPERMINE'>SPM</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=6e8s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6e8s OCA], [http://pdbe.org/6e8s PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6e8s RCSB], [http://www.ebi.ac.uk/pdbsum/6e8s PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6e8s ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

Several turn-on RNA aptamers that activate small-molecule fluorophores have been selected in vitro. Among these, the ~30 nucleotide Mango-III is notable because it binds the thiazole orange derivative TO1-Biotin with high affinity and fluoresces brightly (quantum yield 0.55). Uniquely among related aptamers, Mango-III exhibits biphasic thermal melting, characteristic of molecules with tertiary structure. We report crystal structures of TO1-Biotin complexes of Mango-III, a structure-guided mutant Mango-III(A10U), and a functionally reselected mutant iMango-III. The structures reveal a globular architecture arising from an unprecedented pseudoknot-like connectivity between a G-quadruplex and an embedded non-canonical duplex. The fluorophore is restrained into a planar conformation by the G-quadruplex, a lone, long-range trans Watson-Crick pair (whose A10U mutation increases quantum yield to 0.66), and a pyrimidine perpendicular to the nucleobase planes of those motifs. The improved iMango-III and Mango-III(A10U) fluoresce ~50% brighter than enhanced green fluorescent protein, making them suitable tags for live cell RNA visualization.

Structure and functional reselection of the Mango-III fluorogenic RNA aptamer.,Trachman RJ 3rd, Autour A, Jeng SCY, Abdolahzadeh A, Andreoni A, Cojocaru R, Garipov R, Dolgosheina EV, Knutson JR, Ryckelynck M, Unrau PJ, Ferre-D'Amare AR Nat Chem Biol. 2019 May;15(5):472-479. doi: 10.1038/s41589-019-0267-9. Epub 2019 , Apr 15. PMID:30992561<ref>PMID:30992561</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 6e8s" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Amare, A R.Ferre-D]]

[[Category: Trachman, R J]]

[[Category: G-quadruplex]]

[[Category: Rna]]