View source for 1zhw


==Structure of yeast oxysterol binding protein Osh4 in complex with 20-hydroxycholesterol==
<StructureSection load='1zhw' size='340' side='right'caption='[[1zhw]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1zhw]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZHW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ZHW 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HC2:20-HYDROXYCHOLESTEROL'>HC2</scene>, <scene name='pdbligand=PB:LEAD+(II)+ION'>PB</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=1zhw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zhw OCA], [https://pdbe.org/1zhw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1zhw RCSB], [https://www.ebi.ac.uk/pdbsum/1zhw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1zhw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KES1_YEAST KES1_YEAST] Plays a role in ergosterol synthesis.
== 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/zh/1zhw_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=1zhw ConSurf].
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== Publication Abstract from PubMed ==
The oxysterol-binding-protein (OSBP)-related proteins (ORPs) are conserved from yeast to humans, and are implicated in the regulation of sterol homeostasis and in signal transduction pathways. Here we report the structure of the full-length yeast ORP Osh4 (also known as Kes1) at 1.5-1.9 A resolution in complexes with ergosterol, cholesterol, and 7-, 20- and 25-hydroxycholesterol. We find that a single sterol molecule binds within a hydrophobic tunnel in a manner consistent with a transport function for ORPs. The entrance is blocked by a flexible amino-terminal lid and surrounded by basic residues that are critical for Osh4 function. The structure of the open state of a lid-truncated form of Osh4 was determined at 2.5 A resolution. Structural analysis and limited proteolysis show that sterol binding closes the lid and stabilizes a conformation favouring transport across aqueous barriers and signal transmission. The structure of Osh4 in the absence of ligand exposes potential phospholipid-binding sites that are positioned for membrane docking and sterol exchange. On the basis of these observations, we propose a model in which sterol and membrane binding promote reciprocal conformational changes that facilitate a sterol transfer and signalling cycle.

Structural mechanism for sterol sensing and transport by OSBP-related proteins.,Im YJ, Raychaudhuri S, Prinz WA, Hurley JH Nature. 2005 Sep 1;437(7055):154-8. PMID:16136145<ref>PMID:16136145</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 1zhw" style="background-color:#fffaf0;"></div>

==See Also==
*[[Oxysterol-binding protein homolog|Oxysterol-binding protein homolog]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Hurley JH]]
[[Category: Im YJ]]
[[Category: Prinz WA]]
[[Category: Raychaudhuri S]]