View source for 2hzs


==Structure of the Mediator head submodule Med8C/18/20==
<StructureSection load='2hzs' size='340' side='right'caption='[[2hzs]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2hzs]] is a 12 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=2HZS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HZS 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]] 2.7&#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=2hzs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hzs OCA], [https://pdbe.org/2hzs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hzs RCSB], [https://www.ebi.ac.uk/pdbsum/2hzs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hzs ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MED20_YEAST MED20_YEAST] Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. The Mediator complex, having a compact conformation in its free form, is recruited to promoters by direct interactions with regulatory proteins and serves for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. The Mediator complex unfolds to an extended conformation and partially surrounds RNA polymerase II, specifically interacting with the unphosphorylated form of the C-terminal domain (CTD) of RNA polymerase II. The Mediator complex dissociates from the RNA polymerase II holoenzyme and stays at the promoter when transcriptional elongation begins.<ref>PMID:16076843</ref> <ref>PMID:16109375</ref> <ref>PMID:16263706</ref> <ref>PMID:16885025</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/hz/2hzs_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=2hzs ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Mediator head module stimulates basal RNA polymerase II (Pol II) transcription and enables transcriptional regulation. Here we show that the head subunits Med8, Med18 and Med20 form a subcomplex (Med8/18/20) with two submodules. The highly conserved N-terminal domain of Med8 forms one submodule that binds the TATA box-binding protein (TBP) in vitro and is essential in vivo. The second submodule consists of the C-terminal region of Med8 (Med8C), Med18 and Med20. X-ray analysis of this submodule reveals that Med18 and Med20 form related beta-barrel folds. A conserved putative protein-interaction face on the Med8C/18/20 submodule includes sites altered by srb mutations, which counteract defects resulting from Pol II truncation. Our results and published data support a positive role of the Med8/18/20 subcomplex in initiation-complex formation and suggest that the Mediator head contains a multipartite TBP-binding site that can be modulated by transcriptional activators.

Structure and TBP binding of the Mediator head subcomplex Med8-Med18-Med20.,Lariviere L, Geiger S, Hoeppner S, Rother S, Strasser K, Cramer P Nat Struct Mol Biol. 2006 Oct;13(10):895-901. Epub 2006 Sep 10. PMID:16964259<ref>PMID:16964259</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2hzs" style="background-color:#fffaf0;"></div>

==See Also==
*[[Mediator|Mediator]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Cramer P]]
[[Category: Geiger S]]
[[Category: Hoeppner S]]
[[Category: Lariviere L]]
[[Category: Rother S]]
[[Category: Straesser K]]