View source for 1skx


==Structural Disorder in the Complex of Human PXR and the Macrolide Antibiotic Rifampicin==
<StructureSection load='1skx' size='340' side='right'caption='[[1skx]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1skx]] is a 1 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=1SKX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SKX 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]] 2.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=RFP:RIFAMPICIN'>RFP</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=1skx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1skx OCA], [https://pdbe.org/1skx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1skx RCSB], [https://www.ebi.ac.uk/pdbsum/1skx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1skx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NR1I2_HUMAN NR1I2_HUMAN] Nuclear receptor that binds and is activated by variety of endogenous and xenobiotic compounds. Transcription factor that activates the transcription of multiple genes involved in the metabolism and secretion of potentially harmful xenobiotics, drugs and endogenous compounds. Activated by the antibiotic rifampicin and various plant metabolites, such as hyperforin, guggulipid, colupulone, and isoflavones. Response to specific ligands is species-specific. Activated by naturally occurring steroids, such as pregnenolone and progesterone. Binds to a response element in the promoters of the CYP3A4 and ABCB1/MDR1 genes.<ref>PMID:9727070</ref> <ref>PMID:11668216</ref> <ref>PMID:11297522</ref> <ref>PMID:19297428</ref> <ref>PMID:12578355</ref> <ref>PMID:18768384</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/sk/1skx_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1skx ConSurf].
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== Publication Abstract from PubMed ==
The human nuclear xenobiotic receptor, pregnane X receptor (PXR), detects a variety of structurally distinct endogenous and xenobiotic compounds and controls expression of genes central to drug and cholesterol metabolism. The macrolide antibiotic rifampicin, a front-line treatment for tuberculosis, is an established PXR agonist and, at 823 Da, is one of the largest known ligands for the receptor. We present the 2.8 A crystal structure of the ligand-binding domain of human PXR in complex with rifampicin. We also use structural and mutagenesis data to examine the origins of the directed promiscuity exhibited by the PXRs across species. Three structurally flexible loops adjacent to the ligand-binding pocket of PXR are disordered in this crystal structure, including the 200-210 region that is part of a sequence insert novel to the promiscuous PXRs relative to other members of the nuclear receptor superfamily. The 4-methyl-1-piperazinyl ring of rifampicin, which would lie adjacent to the disordered protein regions, is also disordered and not observed in the structure. Taken together, our results indicate that one wall of the PXR ligand-binding cavity can remain flexible even when the receptor is in complex with an activating ligand. These observations highlight the key role that structural flexibility plays in PXR's promiscuous response to xenobiotics.

Structural disorder in the complex of human pregnane X receptor and the macrolide antibiotic rifampicin.,Chrencik JE, Orans J, Moore LB, Xue Y, Peng L, Collins JL, Wisely GB, Lambert MH, Kliewer SA, Redinbo MR Mol Endocrinol. 2005 May;19(5):1125-34. Epub 2005 Feb 10. PMID:15705662<ref>PMID:15705662</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Pregnane X receptor|Pregnane X receptor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chrencik JE]]
[[Category: Orans JO]]
[[Category: Redinbo MR]]
[[Category: Xue Y]]