View source for 8gxq


==PIC-Mediator in complex with +1 nucleosome (T40N) in MH-binding state==
<StructureSection load='8gxq' size='340' side='right'caption='[[8gxq]], [[Resolution|resolution]] 5.04&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8gxq]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens], [https://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8GXQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8GXQ 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]] 5.04&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <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=8gxq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8gxq OCA], [https://pdbe.org/8gxq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8gxq RCSB], [https://www.ebi.ac.uk/pdbsum/8gxq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8gxq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MED6_HUMAN MED6_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:16595664</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RNA polymerase II-mediated eukaryotic transcription starts with the assembly of the preinitiation complex (PIC) on core promoters. The +1 nucleosome is well positioned about 40 base pairs downstream of the transcription start site (TSS) and is commonly known as a barrier of transcription. The +1 nucleosome-bound PIC-Mediator structures show that PIC-Mediator prefers binding to T40N nucleosome located 40 base pairs downstream of TSS and contacts T50N but not the T70N nucleosome. The nucleosome facilitates the organization of PIC-Mediator on the promoter by binding TFIIH subunit p52 and Mediator subunits MED19 and MED26 and may contribute to transcription initiation. PIC-Mediator exhibits multiple nucleosome-binding patterns, supporting a structural role of the +1 nucleosome in the coordination of PIC-Mediator assembly. Our study reveals the molecular mechanism of PIC-Mediator organization on chromatin and underscores the significance of the +1 nucleosome in regulating transcription initiation.

Structures of +1 nucleosome-bound PIC-Mediator complex.,Chen X, Wang X, Liu W, Ren Y, Qu X, Li J, Yin X, Xu Y Science. 2022 Oct 7;378(6615):62-68. doi: 10.1126/science.abn8131. Epub 2022 Oct , 6. PMID:36201575<ref>PMID:36201575</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8gxq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Xenopus laevis]]
[[Category: Chen X]]
[[Category: Li J]]
[[Category: Liu W]]
[[Category: Qu X]]
[[Category: Ren Y]]
[[Category: Wang X]]
[[Category: Xu Y]]
[[Category: Yin X]]