8f3c: Difference between revisions
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==Cryo-EM consensus structure of Escherichia coli que-PEC (paused elongation complex) RNA Polymerase minus preQ1 ligand== | |||
<StructureSection load='8f3c' size='340' side='right'caption='[[8f3c]], [[Resolution|resolution]] 3.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[8f3c]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8F3C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8F3C FirstGlance]. <br> | |||
</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></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=8f3c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8f3c OCA], [https://pdbe.org/8f3c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8f3c RCSB], [https://www.ebi.ac.uk/pdbsum/8f3c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8f3c ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/RPOA_ECOK1 RPOA_ECOK1] 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 == | |||
Folding of nascent transcripts can be modulated by the RNA polymerase (RNAP) that carries out their transcription, and vice versa. A pause of RNAP during transcription of a preQ(1) riboswitch (termed que-PEC) is stabilized by a previously characterized template consensus sequence and the ligand-free conformation of the nascent RNA. Ligand binding to the riboswitch induces RNAP pause release and downstream transcription termination; however, the mechanism by which riboswitch folding modulates pausing is unclear. Here, we report single-particle cryo-electron microscopy reconstructions of que-PEC in ligand-free and ligand-bound states. In the absence of preQ(1), the RNA transcript is in an unexpected hyper-translocated state, preventing downstream nucleotide incorporation. Strikingly, on ligand binding, the riboswitch rotates around its helical axis, expanding the surrounding RNAP exit channel and repositioning the transcript for elongation. Our study reveals the tight coupling by which nascent RNA structures and their ligands can functionally regulate the macromolecular transcription machinery. | |||
Structural basis for control of bacterial RNA polymerase pausing by a riboswitch and its ligand.,Chauvier A, Porta JC, Deb I, Ellinger E, Meze K, Frank AT, Ohi MD, Walter NG Nat Struct Mol Biol. 2023 Jun 1. doi: 10.1038/s41594-023-01002-x. PMID:37264140<ref>PMID:37264140</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 8f3c" style="background-color:#fffaf0;"></div> | ||
[[Category: | == References == | ||
[[Category: | <references/> | ||
[[Category: | __TOC__ | ||
[[Category: | </StructureSection> | ||
[[Category: | [[Category: Escherichia coli]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Chauvier A]] | ||
[[Category: Deb I]] | |||
[[Category: Ellinger E]] | |||
[[Category: Frank AT]] | |||
[[Category: Meze K]] | |||
[[Category: Ohi MD]] | |||
[[Category: Porta JC]] | |||
[[Category: Walter NG]] | |||