View source for 6f41


==RNA Polymerase III initially transcribing complex==
<SX load='6f41' size='340' side='right' viewer='molstar' caption='[[6f41]], [[Resolution|resolution]] 4.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6f41]] is a 23 chain structure with sequence from [http://en.wikipedia.org/wiki/Baker's_yeast Baker's yeast]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6F41 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6F41 FirstGlance]. <br>
</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='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[6f40|6f40]], [[6f42|6f42]], [[6f44|6f44]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">SPT15, BTF1, TBP1, YER148W ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), BRF1, PCF4, TDS4, YGR246C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), BDP1, TFC5, YNL039W, N2682 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-directed_RNA_polymerase DNA-directed RNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.6 2.7.7.6] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6f41 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6f41 OCA], [http://pdbe.org/6f41 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6f41 RCSB], [http://www.ebi.ac.uk/pdbsum/6f41 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6f41 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/RPAC2_YEAST RPAC2_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common core component of RNA polymerases I and III which synthesize ribosomal RNA precursors and small RNAs, such as 5S rRNA and tRNAs, respectively. [[http://www.uniprot.org/uniprot/RPC8_YEAST RPC8_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNA. The RPC25/RPC8-RPC17/RPC9 subcomplex may bind Pol III transcripts emerging from the adjacent exit pore during elongation. [[http://www.uniprot.org/uniprot/RPC2_YEAST RPC2_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Second largest core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Proposed to contribute to the polymerase catalytic activity and forms the polymerase active center together with the largest subunit. Pol III is composed of mobile elements and RPC2 is part of the core element with the central large cleft and probably a clamp element that moves to open and close the cleft (By similarity). [[http://www.uniprot.org/uniprot/RPC7_YEAST RPC7_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. C31 is involved in the formation of the initiation complex. [[http://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). [[http://www.uniprot.org/uniprot/TBP_YEAST TBP_YEAST]] General transcription factor that functions at the core of the DNA-binding general transcription factor complex TFIID. Binding of TFIID to a promoter (with or without TATA element) is the initial step in preinitiation complex (PIC) formation. TFIID plays a key role in the regulation of gene expression by RNA polymerase II through different activities such as transcription activator interaction, core promoter recognition and selectivity, TFIIA and TFIIB interaction, chromatin modification (histone acetylation by TAF1), facilitation of DNA opening and initiation of transcription.<ref>PMID:9618449</ref> <ref>PMID:12138208</ref> <ref>PMID:12516863</ref>  [[http://www.uniprot.org/uniprot/RPC5_YEAST RPC5_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. The RPC53/RPC4-RPC37/RPC5 subcomplex is required for terminator recognition and reinitiation.<ref>PMID:16362040</ref>  [[http://www.uniprot.org/uniprot/RPC6_YEAST RPC6_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Involved in recruitment of Pol III to the preinitiation complex. Involved in the configuration of an initiation-competent form of RNA polymerase.<ref>PMID:9312031</ref>  [[http://www.uniprot.org/uniprot/RPAB2_YEAST RPAB2_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and small RNAs, such as 5S rRNA and tRNAs, respectively. Pol II is the central component of the basal RNA polymerase II transcription machinery. Pols are composed of mobile elements that move relative to each other. In Pol II, RPB6 is part of the clamp element and togther with parts of RPB1 and RPB2 forms a pocket to which the RPB4-RPB7 subcomplex binds (By similarity). [[http://www.uniprot.org/uniprot/RPAC1_YEAST RPAC1_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I and III which synthesize ribosomal RNA precursors and small RNAs, such as 5S rRNA and tRNAs, respectively. RPAC1 is part of the Pol core element with the central large cleft and probably a clamp element that moves to open and close the cleft (By similarity). [[http://www.uniprot.org/uniprot/RPC10_YEAST RPC10_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Involved in Pol III transcription reinitiation and RNA cleavage during transcription termination. [[http://www.uniprot.org/uniprot/RPAB4_YEAST RPAB4_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and a small RNAs, such as 5S rRNA and tRNAs, respectively. Pols are composed of mobile elements that move relative to each other. In Pol II, the core element with the central large cleft comprises RPB3, RBP10, RPB11, RPB12 and regions of RPB1 and RPB2 forming the active center. [[http://www.uniprot.org/uniprot/RPC4_YEAST RPC4_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Essential for tRNA synthesis. The RPC53/RPC4-RPC37/RPC5 subcomplex is required for terminator recognition and reinitiation.<ref>PMID:16362040</ref>  [[http://www.uniprot.org/uniprot/RPC3_YEAST RPC3_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. [[http://www.uniprot.org/uniprot/TFC5_YEAST TFC5_YEAST]] General activator of RNA polymerase III transcription. [[http://www.uniprot.org/uniprot/RPAB3_YEAST RPAB3_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and small RNAs, such as 5S rRNA and tRNAs, respectively. [[http://www.uniprot.org/uniprot/RPC9_YEAST RPC9_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific peripheric component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. The RPC25/RPC8-RPC17/RPC9 subcomplex may bind Pol III transcripts emerging from the adjacent exit pore during elongation. [[http://www.uniprot.org/uniprot/RPAB5_YEAST RPAB5_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and a small RNAs, such as 5S rRNA and tRNAs, respectively. Pol II is the central component of the basal RNA polymerase II transcription machinery. Pols are composed of mobile elements that move relative to each other. In Pol II, RBP10 is part of the core element with the central large cleft. [[http://www.uniprot.org/uniprot/TF3B_YEAST TF3B_YEAST]] General activator of RNA polymerase III transcription. Interacts with TBP. Binds to Pol III subunit C34 and to the TAU135 component of TFIIIC. [[http://www.uniprot.org/uniprot/RPAB1_YEAST RPAB1_YEAST]] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and small RNAs, such as 5S rRNA and tRNAs, respectively. Pol II is the central component of the basal RNA polymerase II transcription machinery. Pols are composed of mobile elements that move relative to each other. In Pol II, RPB5 is part of the lower jaw surrounding the central large cleft and thought to grab the incoming DNA template. Seems to be the major component in this process (By similarity). 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RNA polymerase III (Pol III) and transcription factor IIIB (TFIIIB) assemble together on different promoter types to initiate the transcription of small, structured RNAs. Here we present structures of Pol III preinitiation complexes, comprising the 17-subunit Pol III and the heterotrimeric transcription factor TFIIIB, bound to a natural promoter in different functional states. Electron cryo-microscopy reconstructions, varying from 3.7 A to 5.5 A resolution, include two early intermediates in which the DNA duplex is closed, an open DNA complex, and an initially transcribing complex with RNA in the active site. Our structures reveal an extremely tight, multivalent interaction between TFIIIB and promoter DNA, and explain how TFIIIB recruits Pol III. Together, TFIIIB and Pol III subunit C37 activate the intrinsic transcription factor-like activity of the Pol III-specific heterotrimer to initiate the melting of double-stranded DNA, in a mechanism similar to that of the Pol II system.

Molecular mechanism of promoter opening by RNA polymerase III.,Vorlander MK, Khatter H, Wetzel R, Hagen WJH, Muller CW Nature. 2018 Jan 17;553(7688):295-300. doi: 10.1038/nature25440. PMID:29345638<ref>PMID:29345638</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6f41" style="background-color:#fffaf0;"></div>

==See Also==
*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
*[[TATA-binding protein 3D structures|TATA-binding protein 3D structures]]
*[[Transcription initiation factors 3D structures|Transcription initiation factors 3D structures]]
== References ==
<references/>
__TOC__
</SX>
[[Category: Baker's yeast]]
[[Category: DNA-directed RNA polymerase]]
[[Category: Large Structures]]
[[Category: Hagen, W J.H]]
[[Category: Khatter, H]]
[[Category: Mueller, C W]]
[[Category: Vorlaender, M K]]
[[Category: Wetzel, R]]
[[Category: Bdp1]]
[[Category: Brf1]]
[[Category: Enzyme]]
[[Category: Pre-initiation complex]]
[[Category: Rna polymerase iii]]
[[Category: Tfiiib]]
[[Category: Transcription]]