View source for 5ddo


==Structural and Dynamic Basis for Low Affinity-High Selectivity Binding of L-glutamine by the Gln-riboswitch==
<StructureSection load='5ddo' size='340' side='right'caption='[[5ddo]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ddo]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synechococcus_elongatus Synechococcus elongatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5DDO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5DDO 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]] 3.1&#8491;</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=5ddo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ddo OCA], [https://pdbe.org/5ddo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ddo RCSB], [https://www.ebi.ac.uk/pdbsum/5ddo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ddo ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SNRPA_HUMAN SNRPA_HUMAN] Binds stem loop II of U1 snRNA. It is the first snRNP to interact with pre-mRNA. This interaction is required for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP. In a snRNP-free form (SF-A) may be involved in coupled pre-mRNA splicing and polyadenylation process. Binds preferentially to the 5'-UGCAC-3' motif in vitro.<ref>PMID:9848648</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Naturally occurring L-glutamine riboswitches occur in cyanobacteria and marine metagenomes, where they reside upstream of genes involved in nitrogen metabolism. By combining X-ray, NMR, and MD, we characterized an L-glutamine-dependent conformational transition in the Synechococcus elongatus glutamine riboswitch from tuning fork to L-shaped alignment of stem segments. This transition generates an open ligand-binding pocket with L-glutamine selectivity enforced by Mg(2+)-mediated intermolecular interactions. The transition also stabilizes the P1 helix through a long-range "linchpin" Watson-Crick G-C pair-capping interaction, while melting a short helix below P1 potentially capable of modulating downstream readout. NMR data establish that the ligand-free glutamine riboswitch in Mg(2+) solution exists in a slow equilibrium between flexible tuning fork and a minor conformation, similar, but not identical, to the L-shaped bound conformation. We propose that an open ligand-binding pocket combined with a high conformational penalty for forming the ligand-bound state provide mechanisms for reducing binding affinity while retaining high selectivity.

Structural and Dynamic Basis for Low-Affinity, High-Selectivity Binding of L-Glutamine by the Glutamine Riboswitch.,Ren A, Xue Y, Peselis A, Serganov A, Al-Hashimi HM, Patel DJ Cell Rep. 2015 Dec 1;13(9):1800-13. doi: 10.1016/j.celrep.2015.10.062. Epub 2015 , Nov 19. PMID:26655897<ref>PMID:26655897</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ddo" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synechococcus elongatus]]
[[Category: Patel D]]
[[Category: Ren A]]