View source for 4fxh


==Crystal structure of the isolated E. coli RelE toxin, P212121 form==
<StructureSection load='4fxh' size='340' side='right'caption='[[4fxh]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4fxh]] is a 2 chain structure with sequence from [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=4FXH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4FXH 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CME:S,S-(2-HYDROXYETHYL)THIOCYSTEINE'>CME</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4fxh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4fxh OCA], [https://pdbe.org/4fxh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4fxh RCSB], [https://www.ebi.ac.uk/pdbsum/4fxh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4fxh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RELE_ECOLI RELE_ECOLI] Toxic component of a toxin-antitoxin (TA) module. A sequence-specific, ribosome-dependent mRNA endoribonuclease that inhibits translation during amino acid starvation (the stringent response). Acts by cleaving mRNA with high codon specificity in the ribosomal A site between positions 2 and 3. The stop codon UAG is cleaved at a fast rate while UAA and UGA are cleaved with intermediate and slow rates. mRNA cleavage can also occur in the ribosomal E site after peptide release from peptidyl-tRNA in the P site as well as on free 30S subunits. Overexpression of RelE results in the inhibition of bacterial growth and a sharp decrease in colony-forming ability which is inhibited by the labile cognate antitoxin RelB. Overexpression also sharply increases persisters (cells that neither grow or die in presence of bactericidal agent and are largely responsible for high levels of biofilm tolerance to antimicrobials). Acts with RelB as a corepressor of relBE transcription.<ref>PMID:9767574</ref> <ref>PMID:11274135</ref> <ref>PMID:11717402</ref> <ref>PMID:12123459</ref> <ref>PMID:12526800</ref> <ref>PMID:19707553</ref>   Seems to be a principal mediator of cell death in liquid media.<ref>PMID:9767574</ref> <ref>PMID:11274135</ref> <ref>PMID:11717402</ref> <ref>PMID:12123459</ref> <ref>PMID:12526800</ref> <ref>PMID:19707553</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The bacterial relBE locus encodes a toxin-antitoxin complex in which the toxin, RelE, is capable of cleaving mRNA in the ribosomal A site cotranslationally. The antitoxin, RelB, both binds and inhibits RelE, and regulates transcription through operator binding and conditional cooperativity controlled by RelE. Here, we present the crystal structure of the intact Escherichia coli RelB2E2 complex at 2.8 A resolution, comprising both the RelB-inhibited RelE and the RelB dimerization domain that binds DNA. RelE and RelB associate into a V-shaped heterotetrameric complex with the ribbon-helix-helix (RHH) dimerization domain at the apex. Our structure supports a model in which relO is optimally bound by two adjacent RelB2E heterotrimeric units, and is not compatible with concomitant binding of two RelB2E2 heterotetramers. The results thus provide a firm basis for understanding the model of conditional cooperativity at the molecular level.

The crystal structure of the intact E. coli RelBE toxin-antitoxin complex provides the structural basis for conditional cooperativity.,Boggild A, Sofos N, Andersen KR, Feddersen A, Easter AD, Passmore LA, Brodersen DE Structure. 2012 Oct 10;20(10):1641-8. doi: 10.1016/j.str.2012.08.017. Epub 2012, Sep 13. PMID:22981948<ref>PMID:22981948</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4fxh" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Boggild A]]
[[Category: Brodersen DE]]
[[Category: Sofos N]]