View source for 2cnk


==Crystal structures of caspase-3 in complex with aza-peptide epoxide inhibitors.==
<StructureSection load='2cnk' size='340' side='right'caption='[[2cnk]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2cnk]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CNK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2CNK 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]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MY2:{1-[(3S)-4-(BENZYLOXY)-3-HYDROXY-4-OXOBUTANOYL]HYDRAZINO}ACETIC+ACID'>MY2</scene>, <scene name='pdbligand=PHQ:BENZYL+CHLOROCARBONATE'>PHQ</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=2cnk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2cnk OCA], [https://pdbe.org/2cnk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2cnk RCSB], [https://www.ebi.ac.uk/pdbsum/2cnk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2cnk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CASP3_HUMAN CASP3_HUMAN] Involved in the activation cascade of caspases responsible for apoptosis execution. At the onset of apoptosis it proteolytically cleaves poly(ADP-ribose) polymerase (PARP) at a '216-Asp-|-Gly-217' bond. Cleaves and activates sterol regulatory element binding proteins (SREBPs) between the basic helix-loop-helix leucine zipper domain and the membrane attachment domain. Cleaves and activates caspase-6, -7 and -9. Involved in the cleavage of huntingtin. Triggers cell adhesion in sympathetic neurons through RET cleavage.<ref>PMID:7596430</ref> <ref>PMID:21357690</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/cn/2cnk_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=2cnk ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Caspase-3 is a prototypic executioner caspase that plays a central role in apoptosis. Aza-peptide epoxides are a novel class of irreversible inhibitors that are highly specific for clan CD cysteine proteases. The five crystal structures of caspase-3-aza-peptide epoxide inhibitor complexes reported here reveal the structural basis for the mechanism of inhibition and the specificities at the S1' and the S4 subsites. Unlike the clan CA cysteine proteases, the catalytic histidine in caspase-3 plays a critical role during protonation and subsequent ring opening of the epoxide moiety and facilitates the nucleophilic attack by the active site cysteine. The nucleophilic attack takes place on the C3 carbon atom of the epoxide and results in an irreversible alkylation of the active site cysteine residue. A favorable network of hydrogen bonds involving the oxyanion hole, catalytic histidine, and the atoms in the prime site of the inhibitor enhance the binding affinity and specificity of the aza-peptide epoxide inhibitors toward caspase-3. The studies also reveal that subtle movements of the N-terminal loop of the beta-subunit occur when the P4 Asp is replaced by a P4 Ile, whereas the N-terminal loop and the safety catch Asp179 are completely disordered when the P4 Asp is replaced by P4 Cbz group.

Exploring the S4 and S1 prime subsite specificities in caspase-3 with aza-peptide epoxide inhibitors.,Ganesan R, Jelakovic S, Campbell AJ, Li ZZ, Asgian JL, Powers JC, Grutter MG Biochemistry. 2006 Aug 1;45(30):9059-67. PMID:16866351<ref>PMID:16866351</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 2cnk" style="background-color:#fffaf0;"></div>

==See Also==
*[[Caspase 3D structures|Caspase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Asgian JL]]
[[Category: Campbell AJ]]
[[Category: Ganesan R]]
[[Category: Grutter MG]]
[[Category: Jelakovic S]]
[[Category: Li ZZ]]
[[Category: Powers JC]]