View source for 3rer


==Crystal structure of E. coli Hfq in complex with AU6A RNA and ADP==
<StructureSection load='3rer' size='340' side='right'caption='[[3rer]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3rer]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BL21 Escherichia coli BL21]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3RER OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3RER 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <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=3rer FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3rer OCA], [https://pdbe.org/3rer PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3rer RCSB], [https://www.ebi.ac.uk/pdbsum/3rer PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3rer 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 ==
Hfq is a bacterial post-transcriptional regulator. It facilitates base-pairing between sRNA and target mRNA. Hfq mediates DsrA-dependent translational activation of rpoS mRNA at low temperatures. rpoS encodes the stationary-phase sigma factor sigma(S), which is the central regulator in general stress response. However, structural information on Hfq-DsrA interaction is not yet available. Although Hfq is reported to hydrolyze ATP, the ATP-binding site is still unknown. Here, we report a ternary crystal complex structure of Escherichia coli Hfq bound to a major Hfq recognition region on DsrA (AU(6)A) together with ADP, and a crystal complex structure of Hfq bound to ADP. AU(6)A binds to the proximal and distal sides of two Hfq hexamers. ADP binds to a purine-selective site on the distal side and contacts conserved arginine or glutamine residues on the proximal side of another hexamer. This binding mode is different from previously postulated. The cooperation of two different Hfq hexamers upon nucleic acid binding in solution is verified by fluorescence polarization and solution nuclear magnetic resonance (NMR) experiments using fragments of Hfq and DsrA. Fluorescence resonance energy transfer conducted with full-length Hfq and DsrA also supports cooperation of Hfq hexamers upon DsrA binding. The implications of Hfq hexamer cooperation have been discussed.

Cooperation of Escherichia coli Hfq hexamers in DsrA binding.,Wang W, Wang L, Zou Y, Zhang J, Gong Q, Wu J, Shi Y Genes Dev. 2011 Oct 1;25(19):2106-17. PMID:21979921<ref>PMID:21979921</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 3rer" style="background-color:#fffaf0;"></div>

==See Also==
*[[Protein Hfq 3D structures|Protein Hfq 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli BL21]]
[[Category: Large Structures]]
[[Category: Shi YY]]
[[Category: Wang WW]]
[[Category: Wu JH]]