View source for 2zpq


==Crystal structure of anionic trypsin isoform 1 from chum salmon==
<StructureSection load='2zpq' size='340' side='right'caption='[[2zpq]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zpq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Oncorhynchus_keta Oncorhynchus keta]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZPQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZPQ 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BEN:BENZAMIDINE'>BEN</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</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=2zpq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zpq OCA], [https://pdbe.org/2zpq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zpq RCSB], [https://www.ebi.ac.uk/pdbsum/2zpq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zpq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q8AV11_ONCKE Q8AV11_ONCKE] 
== 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/zp/2zpq_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=2zpq ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Three anionic salmon trypsin isoforms (CST-1, CST-2 and CST-3) were isolated from the pyloric caeca of chum salmon (Oncorhynchus keta). The order of catalytic efficiency (K(m)/k(cat)) of the isoforms during BAPA hydrolysis was CST-2 &gt; CST-1 &gt; CST-3. In order to find a structural rationalization for the observed difference in catalytic efficiency, the X-ray crystallographic structures of the three isoforms were compared in detail. Some structural differences were observed in the C-terminal alpha-helix, interdomain loop and active-site region. From the results of the detailed comparison, it appears that the structural flexibility of the C-terminal alpha-helix, which interacts with the N-terminal domain, and the substrate-binding pocket in CST-3 are lower than those in CST-1 and CST-2. In addition, the conformation of the catalytic triad (His57, Asp102 and Ser195) differs among the three isoforms. The imidazole N atom of His57 in CST-1 and CST-2 forms a hydrogen bond to the hydroxyl O atom of Ser195, but the distance between the imidazole N atom of His57 and the hydroxyl O atom of Ser195 in CST-3 is too great (3.8 A) for the formation of a hydrogen bond. Thus, the nucleophilicity of the hydroxyl group of Ser195 in CST-3 is weaker than that in CST-1 or CST-2. Furthermore, the electrostatic potential of the substrate-binding pocket in CST-2 is markedly lower than those in CST-1 and CST-3 owing to the negative charges of Asp150, Asp153 and Glu221B that arise from the long-range effect. These results may explain the higher catalytic efficiency of CST-2 compared with CST-1 and CST-3.

A structural comparison of three isoforms of anionic trypsin from chum salmon (Oncorhynchus keta).,Toyota E, Iyaguchi D, Sekizaki H, Tateyama M, Ng KK Acta Crystallogr D Biol Crystallogr. 2009 Jul;65(Pt 7):717-23. Epub 2009, Jun 20. PMID:19564692<ref>PMID:19564692</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 2zpq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Trypsin 3D structures|Trypsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Oncorhynchus keta]]
[[Category: Iyaguchi D]]
[[Category: Toyota E]]