2nxx

<StructureSection load='2nxx' size='340' side='right' caption='[[2nxx]], [[Resolution|resolution]] 2.75&Aring;' scene=''>

<table><tr><td colspan='2'>[[2nxx]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Red_flour_beetle Red flour beetle]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NXX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2NXX FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=P1A:2,3,14,20,22-PENTAHYDROXYCHOLEST-7-EN-6-ONE'>P1A</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Ultraspiracle (USP) ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=7070 Red flour beetle]), Ecdysone Receptor (EcR) ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=7070 Red flour beetle])</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=2nxx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2nxx OCA], [http://pdbe.org/2nxx PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2nxx RCSB], [http://www.ebi.ac.uk/pdbsum/2nxx PDBsum]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/nx/2nxx_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

Retinoid X receptor (RXR) and Ultraspiracle (USP) play a central role as ubiquitous heterodimerization partners of many nuclear receptors. While it has long been accepted that a wide range of ligands can activate vertebrate/mollusc RXRs, the existence and necessity of specific endogenous ligands activating RXR-USP in vivo is still matter of intense debate. Here we report the existence of a novel type of RXR-USP with a ligand-independent functional conformation. Our studies involved Tribolium USP (TcUSP) as representative of most arthropod RXR-USPs, with high sequence homology to vertebrate/mollusc RXRs. The crystal structure of the ligand-binding domain of TcUSP was solved in the context of the functional heterodimer with the ecdysone receptor (EcR). While EcR exhibits a canonical ligand-bound conformation, USP adopts an original apo structure. Our functional data demonstrate that TcUSP is a constitutively silent partner of EcR, and that none of the RXR ligands can bind and activate TcUSP. These findings together with a phylogenetic analysis suggest that RXR-USPs have undergone remarkable functional shifts during evolution and give insight into receptor-ligand binding evolution and dynamics.

Structural and functional characterization of a novel type of ligand-independent RXR-USP receptor.,Iwema T, Billas IM, Beck Y, Bonneton F, Nierengarten H, Chaumot A, Richards G, Laudet V, Moras D EMBO J. 2007 Aug 22;26(16):3770-82. Epub 2007 Aug 2. PMID:17673910<ref>PMID:17673910</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 2nxx" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Red flour beetle]]

[[Category: Billas, I]]

[[Category: Iwema, T]]

[[Category: Moras, D]]

[[Category: Apo and holo ligand binding pocket]]

[[Category: Hormone-growth factor complex]]