View source for 4phq


==ClyA CC6/264 ox (6-303)==
<StructureSection load='4phq' size='340' side='right'caption='[[4phq]], [[Resolution|resolution]] 1.94&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4phq]] is a 4 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=4PHQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4PHQ 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]] 1.94&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=4phq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4phq OCA], [https://pdbe.org/4phq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4phq RCSB], [https://www.ebi.ac.uk/pdbsum/4phq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4phq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HLYE_ECOLI HLYE_ECOLI] Toxin, which has some hemolytic activity towards mammalian cells. Acts by forming a pore-like structure upon contact with mammalian cells.<ref>PMID:14532000</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The alpha-pore-forming toxin Cytolysin A (ClyA) is responsible for the hemolytic phenotype of several Escherichia coli and Salmonella enterica strains. ClyA is a soluble, 34 kDa monomer that assembles into a dodecameric pore complex in the presence of membranes or detergent. The comparison of the X-ray structures of monomeric ClyA and the ClyA protomer in the pore complex revealed one of the largest conformational transitions observed so far in proteins, involving the structural rearrangement of more than half of all residues, which is consistent with the finding that conversion from the monomer to the assembly competent protomer is rate-limiting for pore assembly. Here, we introduced artificial disulfide bonds at two distinct sites into the ClyA monomer that both prevent a specific structural rearrangement required for protomer formation. Using electron microscopy and hemolytic activity assays, we show that the engineered disulfides indeed trap these ClyA variants in an assembly incompetent state. Assembly of the variants into functional pore complexes can be completely recovered by disulfide reduction. The assembly kinetics of the ClyA variants recorded with circular dichroism and fluorescence spectroscopy revealed the same mechanism of protomer formation that was observed for wild-type ClyA, proceeding via an intermediate with decreased secondary structure content.

Characterization of Variants of the Pore-Forming Toxin ClyA from Escherichia coli Controlled by a Redox Switch.,Roderer D, Benke S, Muller M, Fah-Rechsteiner H, Ban N, Schuler B, Glockshuber R Biochemistry. 2014 Sep 30. PMID:25222267<ref>PMID:25222267</ref>

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

==See Also==
*[[Hemolysin 3D structures|Hemolysin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Ban N]]
[[Category: Glockshuber R]]
[[Category: Roderer DJA]]