View source for 4qvd


==E.coli Hfq in complex with RNA Ads==
<StructureSection load='4qvd' size='340' side='right'caption='[[4qvd]], [[Resolution|resolution]] 1.97&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4qvd]] is a 7 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=4QVD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4QVD 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]] 1.972&#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=4qvd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qvd OCA], [https://pdbe.org/4qvd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4qvd RCSB], [https://www.ebi.ac.uk/pdbsum/4qvd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4qvd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C1IFD2_ECOLX C1IFD2_ECOLX] 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. Also binds with high specificity to tRNAs.[HAMAP-Rule:MF_00436]
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== Publication Abstract from PubMed ==
Small RNA OxyS is induced during oxidative stress in Escherichia coli and it is an Hfq-dependent negative regulator of mRNA translation. OxyS represses the translation of fhlA and rpoS mRNA, which encode the transcriptional activator and sigma(s) subunit of RNA polymerase, respectively. However, little is known regarding how Hfq, an RNA chaperone, interacts with OxyS at the atomic level. Here, using fluorescence polarization and tryptophan fluorescence quenching assays, we verified that the A-rich linker region of OxyS sRNA binds Hfq at its distal side. We also report two crystal structures of Hfq in complex with A-rich RNA fragments from this linker region. Both of these RNA fragments bind to the distal side of Hfq and adopt a different conformation compared with those previously reported for the (A-R-N)n tripartite recognition motif. Furthermore, using fluorescence polarization, electrophoresis mobility shift assays and in vivo translation assays, we found that an Hfq mutant, N48A, increases the binding affinity of OxyS for Hfq in vitro but is defective in the negative regulation of fhlA translation in vivo, suggesting that the normal function of OxyS depends on the details of the interaction with Hfq that may be related to the rapid recycling of Hfq in the cell.

Structural insights into the recognition of the internal A-rich linker from OxyS sRNA by Escherichia coli Hfq.,Wang L, Wang W, Li F, Zhang J, Wu J, Gong Q, Shi Y Nucleic Acids Res. 2015 Feb 27;43(4):2400-11. doi: 10.1093/nar/gkv072. Epub 2015 , Feb 10. PMID:25670676<ref>PMID:25670676</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4qvd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Protein Hfq 3D structures|Protein Hfq 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Gong QG]]
[[Category: Li FD]]
[[Category: Shi YY]]
[[Category: Wang LJ]]
[[Category: Wang WW]]
[[Category: Wu JH]]