View source for 2h5j


==Crystal strusture of caspase-3 with inhibitor Ac-DMQD-Cho==
<StructureSection load='2h5j' size='340' side='right'caption='[[2h5j]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2h5j]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2H5J OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2H5J 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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=ASJ:(3S)-3-AMINO-4-HYDROXYBUTANOIC+ACID'>ASJ</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=2h5j FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2h5j OCA], [https://pdbe.org/2h5j PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2h5j RCSB], [https://www.ebi.ac.uk/pdbsum/2h5j PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2h5j 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/h5/2h5j_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=2h5j ConSurf].
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== Publication Abstract from PubMed ==
The molecular basis for the substrate specificity of human caspase-3 has been investigated using peptide analog inhibitors and substrates that vary at the P2, P3, and P5 positions. Crystal structures were determined of caspase-3 complexes with the substrate analogs at resolutions of 1.7 A to 2.3 A. Differences in the interactions of caspase-3 with the analogs are consistent with the Ki values of 1.3 nM, 6.5 nM, and 12.4 nM for Ac-DEVD-Cho, Ac-VDVAD-Cho and Ac-DMQD-Cho, respectively, and relative kcat/Km values of 100%, 37% and 17% for the corresponding peptide substrates. The bound peptide analogs show very similar interactions for the main-chain atoms and the conserved P1 Asp and P4 Asp, while interactions vary for P2 and P3. P2 lies in a hydrophobic S2 groove, consistent with the weaker inhibition of Ac-DMQD-Cho with polar P2 Gln. S3 is a surface hydrophilic site with favorable polar interactions with P3 Glu in Ac-DEVD-Cho. Ac-DMQD-Cho and Ac-VDVAD-Cho have hydrophobic P3 residues that are not optimal in the polar S3 site, consistent with their weaker inhibition. A hydrophobic S5 site was identified for caspase-3, where the side-chains of Phe250 and Phe252 interact with P5 Val of Ac-VDVAD-Cho, and enclose the substrate-binding site by conformational change. The kinetic importance of hydrophobic P5 residues was confirmed by more efficient hydrolysis of caspase-3 substrates Ac-VDVAD-pNA and Ac-LDVAD-pNA compared with Ac-DVAD-pNA. In contrast, caspase-7 showed less efficient hydrolysis of the substrates with P5 Val or Leu compared with Ac-DVAD-pNA. Caspase-3 and caspase-2 share similar hydrophobic S5 sites, while caspases 1, 7, 8 and 9 do not have structurally equivalent hydrophobic residues; these caspases are likely to differ in their selectivity for the P5 position of substrates. The distinct selectivity for P5 will help define the particular substrates and signaling pathways associated with each caspase.

Structural and kinetic analysis of caspase-3 reveals role for s5 binding site in substrate recognition.,Fang B, Boross PI, Tozser J, Weber IT J Mol Biol. 2006 Jul 14;360(3):654-66. Epub 2006 Jun 2. PMID:16781734<ref>PMID:16781734</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 2h5j" style="background-color:#fffaf0;"></div>

==See Also==
*[[Caspase 3D structures|Caspase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Boross PI]]
[[Category: Fang B]]
[[Category: Tozser J]]
[[Category: Weber IT]]