View source for 7ogm


==A cooperative PNPase-Hfq-RNA carrier complex facilitates bacterial riboregulation. PNPase-3'ETS(leuZ)-Hfq==
<StructureSection load='7ogm' size='340' side='right'caption='[[7ogm]], [[Resolution|resolution]] 3.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7ogm]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7OGM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7OGM 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]] 3.7&#8491;</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=7ogm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ogm OCA], [https://pdbe.org/7ogm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ogm RCSB], [https://www.ebi.ac.uk/pdbsum/7ogm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ogm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HFQ_ECOLI HFQ_ECOLI] RNA chaperone that binds small regulatory RNA (sRNAs) and mRNAs to facilitate mRNA translational regulation in response to envelope stress, environmental stress and changes in metabolite concentrations. Involved in the regulation of stress responses mediated by the sigma factors RpoS, sigma-E and sigma-32. Binds with high specificity to tRNAs. In vitro, stimulates synthesis of long tails by poly(A) polymerase I. Required for RNA phage Qbeta replication.<ref>PMID:805130</ref> <ref>PMID:10677490</ref> <ref>PMID:11222598</ref> <ref>PMID:17158661</ref> <ref>PMID:19909729</ref>   Seems to play a role in persister cell formation; upon overexpression decreases persister cell formation while deletion increases persister formation.<ref>PMID:805130</ref> <ref>PMID:10677490</ref> <ref>PMID:11222598</ref> <ref>PMID:17158661</ref> <ref>PMID:19909729</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Polynucleotide phosphorylase (PNPase) is an ancient exoribonuclease conserved in the course of evolution and is found in species as diverse as bacteria and humans. Paradoxically, Escherichia coli PNPase can act not only as an RNA degrading enzyme but also by an unknown mechanism as a chaperone for small regulatory RNAs (sRNAs), with pleiotropic consequences for gene regulation. We present structures of the ternary assembly formed by PNPase, the RNA chaperone Hfq, and sRNA and show that this complex boosts sRNA stability in vitro. Comparison of structures for PNPase in RNA carrier and degradation modes reveals how the RNA is rerouted away from the active site through interactions with Hfq and the KH and S1 domains. Together, these data explain how PNPase is repurposed to protect sRNAs from cellular ribonucleases such as RNase E and could aid RNA presentation to facilitate regulatory actions on target genes.

A cooperative PNPase-Hfq-RNA carrier complex facilitates bacterial riboregulation.,Dendooven T, Sinha D, Roeselova A, Cameron TA, De Lay NR, Luisi BF, Bandyra KJ Mol Cell. 2021 Jun 17. pii: S1097-2765(21)00445-7. doi:, 10.1016/j.molcel.2021.05.032. PMID:34157309<ref>PMID:34157309</ref>

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

==See Also==
*[[Protein Hfq 3D structures|Protein Hfq 3D structures]]
*[[Ribonuclease 3D structures|Ribonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Bandyra K]]
[[Category: Cameron TA]]
[[Category: De Lay N]]
[[Category: Dendooven T]]
[[Category: Luisi BF]]
[[Category: Roesoleva A]]
[[Category: Sinha D]]