View source for 4ls4


==Crystal structure of L66S mutant toxin from Helicobacter pylori==
<StructureSection load='4ls4' size='340' side='right'caption='[[4ls4]], [[Resolution|resolution]] 1.66&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ls4]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori_26695 Helicobacter pylori 26695]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4LS4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4LS4 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]] 1.66&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=4ls4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ls4 OCA], [https://pdbe.org/4ls4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ls4 RCSB], [https://www.ebi.ac.uk/pdbsum/4ls4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ls4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/O25554_HELPY O25554_HELPY] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The toxin-antitoxin (TA) systems widely spread among bacteria and archaea are important for antibiotic resistance and microorganism virulence. The bacterial kingdom uses TA systems to adjust the global level of gene expression and translation through RNA degradation. In Helicobacter pylori, only two TA systems are known thus far. Our previous studies showed that HP0894-HP0895 acts as a TA system and that HP0894 exhibits intrinsic RNase activity. However, the precise molecular basis for interaction with substrate or antitoxin and the mechanism of mRNA cleavage remain unclear. Therefore, in an attempt to shed some light on the mechanism behind the TA system of HP0894-HP0895, here we present the crystal structures of apo- and metal-bound H. pylori 0894 at 1.28A and 1.89A, respectively. Through the combined approach of structural analysis and structural homology search, the amino acids involved in mRNase active site were monitored and the reorientations of different residues were discussed in detail. In the mRNase active site of HP0894 toxin, His84 acts as a catalytic residue and reorients itself to exhibit this type of activity, acting as a general acid in an acid-base catalysis reaction, while His47 and His60 stabilize the transition state. Lys52, Glu58, Asp64 and Arg80 have phosphate binding and specific sequence recognition. Glu58 also acts as a general base, and substrate reorientation is caused by Phe88. Based on experimental findings, a model for antitoxin binding could be suggested.

Crystal structure of apo and copper bound HP0894 toxin from Helicobacter pylori 26695 and insight into mRNase activity.,Pathak C, Im H, Yang YJ, Yoon HJ, Kim HM, Kwon AR, Lee BJ Biochim Biophys Acta. 2013 Dec;1834(12):2579-90. doi:, 10.1016/j.bbapap.2013.09.006. Epub 2013 Sep 21. PMID:24060809<ref>PMID:24060809</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ls4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Helicobacter pylori 26695]]
[[Category: Large Structures]]
[[Category: Im H]]
[[Category: Lee BJ]]
[[Category: Pathak CC]]
[[Category: Yoon HJ]]