View source for 3aoi


==RNA polymerase-Gfh1 complex (Crystal type 2)==
<StructureSection load='3aoi' size='340' side='right'caption='[[3aoi]], [[Resolution|resolution]] 4.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3aoi]] is a 24 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB8 Thermus thermophilus HB8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3AOI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3AOI 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]] 4.3&#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=3aoi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3aoi OCA], [https://pdbe.org/3aoi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3aoi RCSB], [https://www.ebi.ac.uk/pdbsum/3aoi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3aoi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RPOB_THET8 RPOB_THET8] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The multi-subunit DNA-dependent RNA polymerase (RNAP) is the principal enzyme of transcription for gene expression. Transcription is regulated by various transcription factors. Gre factor homologue 1 (Gfh1), found in the Thermus genus, is a close homologue of the well-conserved bacterial transcription factor GreA, and inhibits transcription initiation and elongation by binding directly to RNAP. The structural basis of transcription inhibition by Gfh1 has remained elusive, although the crystal structures of RNAP and Gfh1 have been determined separately. Here we report the crystal structure of Thermus thermophilus RNAP complexed with Gfh1. The amino-terminal coiled-coil domain of Gfh1 fully occludes the channel formed between the two central modules of RNAP; this channel would normally be used for nucleotide triphosphate (NTP) entry into the catalytic site. Furthermore, the tip of the coiled-coil domain occupies the NTP beta-gamma phosphate-binding site. The NTP-entry channel is expanded, because the central modules are 'ratcheted' relative to each other by approximately 7 degrees , as compared with the previously reported elongation complexes. This 'ratcheted state' is an alternative structural state, defined by a newly acquired contact between the central modules. Therefore, the shape of Gfh1 is appropriate to maintain RNAP in the ratcheted state. Simultaneously, the ratcheting expands the nucleic-acid-binding channel, and kinks the bridge helix, which connects the central modules. Taken together, the present results reveal that Gfh1 inhibits transcription by preventing NTP binding and freezing RNAP in the alternative structural state. The ratcheted state might also be associated with other aspects of transcription, such as RNAP translocation and transcription termination.

Crystal structure of bacterial RNA polymerase bound with a transcription inhibitor protein.,Tagami S, Sekine S, Kumarevel T, Hino N, Murayama Y, Kamegamori S, Yamamoto M, Sakamoto K, Yokoyama S Nature. 2010 Dec 16;468(7326):978-82. Epub 2010 Dec 1. PMID:21124318<ref>PMID:21124318</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 3aoi" style="background-color:#fffaf0;"></div>

==See Also==
*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus HB8]]
[[Category: Kumarevel T]]
[[Category: Sekine S]]
[[Category: Tagami S]]
[[Category: Yamamoto M]]
[[Category: Yokoyama S]]