View source for 5lyu


==The native crystal structure of 7SK 5'-hairpin==
<StructureSection load='5lyu' size='340' side='right'caption='[[5lyu]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5lyu]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5LYU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5LYU 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CCC:CYTIDINE-5-PHOSPHATE-2,3-CYCLIC+PHOSPHATE'>CCC</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></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=5lyu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5lyu OCA], [https://pdbe.org/5lyu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5lyu RCSB], [https://www.ebi.ac.uk/pdbsum/5lyu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5lyu ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
In vertebrates, the 7SK RNA forms the scaffold of a complex, which regulates transcription pausing of RNA-polymerase II. By binding to the HEXIM protein, the complex comprising proteins LARP7 and MePCE captures the positive transcription elongation factor P-TEFb and prevents phosphorylation of pausing factors. The HEXIM-binding site embedded in the 5'-hairpin of 7SK (HP1) encompasses a short signature sequence, a GAUC repeat framed by single-stranded uridines. The present crystal structure of HP1 shows a remarkably straight helical stack involving several unexpected triples formed at a central region. Surprisingly, two uridines of the signature sequence make triple interactions in the major groove of the (GAUC)2 The third uridine is turned outwards or inward, wedging between the other uridines, thus filling the major groove. A molecular dynamics simulation indicates that these two conformations of the signature sequence represent stable alternatives. Analyses of the interaction with the HEXIM protein confirm the importance of the triple interactions at the signature sequence. Altogether, the present structural analysis of 7SK HP1 highlights an original mechanism of swapping bases, which could represent a possible '7SK signature' and provides new insight into the functional importance of the plasticity of RNA.

The crystal structure of the 5' functional domain of the transcription riboregulator 7SK.,Martinez-Zapien D, Legrand P, McEwen AG, Proux F, Cragnolini T, Pasquali S, Dock-Bregeon AC Nucleic Acids Res. 2017 Jan 12. pii: gkw1351. doi: 10.1093/nar/gkw1351. PMID:28082395<ref>PMID:28082395</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5lyu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Dock-Bregeon A-C]]
[[Category: Legrand P]]
[[Category: Martinez-Zapien D]]
[[Category: McEwen AC]]
[[Category: Pasquali S]]