View source for 7enj


==Human Mediator (deletion of MED1-IDR) in a Tail-bent conformation (MED-B)==
<StructureSection load='7enj' size='340' side='right'caption='[[7enj]], [[Resolution|resolution]] 4.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7enj]] is a 10 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=7ENJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ENJ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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=7enj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7enj OCA], [https://pdbe.org/7enj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7enj RCSB], [https://www.ebi.ac.uk/pdbsum/7enj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7enj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MED30_HUMAN MED30_HUMAN] 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. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors.<ref>PMID:11909976</ref> <ref>PMID:16595664</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 1.3-megadalton transcription factor IID (TFIID) is required for preinitiation complex (PIC) assembly and RNA polymerase II (Pol II)-mediated transcription initiation on almost all genes. The 26-subunit Mediator stimulates transcription and cyclin-dependent kinase 7 (CDK7)-mediated phosphorylation of the Pol II C-terminal domain (CTD). We determined the structures of human Mediator in the Tail module-extended (at near-atomic resolution) and Tail-bent conformations and structures of TFIID-based PIC-Mediator (76 polypeptides, ~4.1 megadaltons) in four distinct conformations. PIC-Mediator assembly induces concerted reorganization (Head-tilting and Middle-down) of Mediator and creates a Head-Middle sandwich, which stabilizes two CTD segments and brings CTD to CDK7 for phosphorylation; this suggests a CTD-gating mechanism favorable for phosphorylation. The TFIID-based PIC architecture modulates Mediator organization and TFIIH stabilization, underscoring the importance of TFIID in orchestrating PIC-Mediator assembly.

Structures of the human Mediator and Mediator-bound preinitiation complex.,Chen X, Yin X, Li J, Wu Z, Qi Y, Wang X, Liu W, Xu Y Science. 2021 Jun 4;372(6546):eabg0635. doi: 10.1126/science.abg0635. Epub 2021 , May 6. PMID:33958484<ref>PMID:33958484</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7enj" style="background-color:#fffaf0;"></div>

==See Also==
*[[Mediator|Mediator]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Li J]]
[[Category: Liu W]]
[[Category: Wu Z]]
[[Category: Xu Y]]
[[Category: Yin X]]