View source for 3lqx


==SRP ribonucleoprotein core complexed with cobalt hexammine==
<StructureSection load='3lqx' size='340' side='right'caption='[[3lqx]], [[Resolution|resolution]] 1.93&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3lqx]] is a 2 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=3LQX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3LQX 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]] 1.93&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CCC:CYTIDINE-5-PHOSPHATE-2,3-CYCLIC+PHOSPHATE'>CCC</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=NCO:COBALT+HEXAMMINE(III)'>NCO</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=3lqx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3lqx OCA], [https://pdbe.org/3lqx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3lqx RCSB], [https://www.ebi.ac.uk/pdbsum/3lqx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3lqx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SRP54_ECOLI SRP54_ECOLI] Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Binds to the hydrophobic signal sequence of the ribosome-nascent chain (RNC) as it emerges from the ribosomes. The SRP-RNC complex is then targeted to the cytoplasmic membrane where it interacts with the SRP receptor FtsY. Interaction with FtsY leads to the transfer of the RNC complex to the Sec translocase for insertion into the membrane, the hydrolysis of GTP by both Ffh and FtsY, and the dissociation of the SRP-FtsY complex into the individual components.<ref>PMID:2171778</ref> <ref>PMID:1279430</ref> <ref>PMID:1331806</ref> <ref>PMID:9305630</ref> <ref>PMID:11735405</ref> <ref>PMID:11741850</ref> <ref>PMID:15140892</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lq/3lqx_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3lqx ConSurf].
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== Publication Abstract from PubMed ==
The signal recognition particle (SRP) targets proteins to the endoplasmic reticulum in eukaryotes or to the inner membrane in prokaryotes by binding to hydrophobic signal sequences. Signal peptide recognition occurs within the highly conserved RNA-protein core of the SRP, underscoring the importance of this complex in SRP function. Structural analysis of the RNA and protein components of the prokaryotic SRP in the free and bound states revealed that the RNA undergoes a significant conformational change upon protein binding involving the uptake of several monovalent and divalent cations. To investigate the role of these metal ions in formation of the functional SRP complex, we used binding affinity assays and X-ray crystallography to analyze the specificity and energetic contributions of mono- and divalent metal ions bound in the RNA. Our results demonstrate that several metal ion binding sites important for RNA conformation can accommodate chemically distinct ions, often without affecting the structure of the complex. Thus, while these metal ions are highly ordered and essential for the formation and stability of the SRP complex, they behave like nonspecific metal ions.

Structural and energetic analysis of metal ions essential to SRP signal recognition domain assembly.,Batey RT, Doudna JA Biochemistry. 2002 Oct 1;41(39):11703-10. PMID:12269812<ref>PMID:12269812</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 3lqx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Signal recognition particle 3D structures|Signal recognition particle 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Batey RT]]