View source for 7z1n


==Structure of yeast RNA Polymerase III Delta C53-C37-C11==
<StructureSection load='7z1n' size='340' side='right'caption='[[7z1n]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7z1n]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_W303 Saccharomyces cerevisiae W303]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7Z1N OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7Z1N 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]] 3.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1N7:CHAPSO'>1N7</scene>, <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=7z1n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7z1n OCA], [https://pdbe.org/7z1n PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7z1n RCSB], [https://www.ebi.ac.uk/pdbsum/7z1n PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7z1n ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RPC1_YEAST RPC1_YEAST] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Forms the polymerase active center together with the second largest subunit. A single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol III. A bridging helix emanates from RPC1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol III by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition (By similarity).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RNA polymerase (Pol) III is specialized to transcribe short, abundant RNAs, for which it terminates transcription on polythymine (dT) stretches on the non-template (NT) strand. When Pol III reaches the termination signal, it pauses and forms the pre-termination complex (PTC). Here, we report cryoelectron microscopy (cryo-EM) structures of the yeast Pol III PTC and complementary functional states at resolutions of 2.7-3.9 A. Pol III recognizes the poly(dT) termination signal with subunit C128 that forms a hydrogen-bond network with the NT strand and, thereby, induces pausing. Mutating key interacting residues interferes with transcription termination in vitro, impairs yeast growth, and causes global termination defects in vivo, confirming our structural results. Additional cryo-EM analysis reveals that C53-C37, a Pol III subcomplex and key termination factor, participates indirectly in Pol III termination. We propose a mechanistic model of Pol III transcription termination and rationalize why Pol III, unlike Pol I and Pol II, terminates on poly(dT) signals.

Architecture of the yeast Pol III pre-termination complex and pausing mechanism on poly(dT) termination signals.,Girbig M, Xie J, Grotsch H, Libri D, Porrua O, Muller CW Cell Rep. 2022 Sep 6;40(10):111316. doi: 10.1016/j.celrep.2022.111316. PMID:36070694<ref>PMID:36070694</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7z1n" style="background-color:#fffaf0;"></div>

==See Also==
*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae W303]]
[[Category: Girbig M]]
[[Category: Mueller CW]]