View source for 5w66


==RNA polymerase I Initial Transcribing Complex State 3==
<SX load='5w66' size='340' side='right' viewer='molstar' caption='[[5w66]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5w66]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_S288C Saccharomyces cerevisiae S288C]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5W66 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5W66 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=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=5w66 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5w66 OCA], [https://pdbe.org/5w66 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5w66 RCSB], [https://www.ebi.ac.uk/pdbsum/5w66 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5w66 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RPA1_YEAST RPA1_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 I which synthesizes ribosomal RNA precursors. 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 I. A bridging helix emanates from RPA1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol I 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).
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== Publication Abstract from PubMed ==
Transcription initiation by RNA Polymerase I (Pol I) depends on the Core Factor (CF) complex to recognize the upstream promoter and assemble into a Pre-Initiation Complex (PIC). Here, we solve a structure of Saccharomyces cerevisiae Pol I-CF-DNA to 3.8 A resolution using single-particle cryo-electron microscopy. The structure reveals a bipartite architecture of Core Factor and its recognition of the promoter from -27 to -16. Core Factor's intrinsic mobility correlates well with different conformational states of the Pol I cleft, in addition to the stabilization of either Rrn7 N-terminal domain near Pol I wall or the tandem winged helix domain of A49 at a partially overlapping location. Comparison of the three states in this study with the Pol II system suggests that a ratchet motion of the Core Factor-DNA sub-complex at upstream facilitates promoter melting in an ATP-independent manner, distinct from a DNA translocase actively threading the downstream DNA in the Pol II PIC.

Structural mechanism of ATP-independent transcription initiation by RNA polymerase I.,Han Y, Yan C, Nguyen THD, Jackobel AJ, Ivanov I, Knutson BA, He Y Elife. 2017 Jun 17;6. pii: e27414. doi: 10.7554/eLife.27414. PMID:28623663<ref>PMID:28623663</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 5w66" style="background-color:#fffaf0;"></div>

==See Also==
*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
*[[Transcription initiation factors 3D structures|Transcription initiation factors 3D structures]]
== References ==
<references/>
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[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae S288C]]
[[Category: Han Y]]
[[Category: He Y]]