View source for 2z39


==Crystal structure of Brassica juncea chitinase catalytic module Glu234Ala mutant (Bjchi3-E234A)==
<StructureSection load='2z39' size='340' side='right'caption='[[2z39]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2z39]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Brassica_juncea Brassica juncea]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2Z39 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2Z39 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=2z39 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2z39 OCA], [https://pdbe.org/2z39 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2z39 RCSB], [https://www.ebi.ac.uk/pdbsum/2z39 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2z39 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q9SQF7_BRAJU Q9SQF7_BRAJU] 
== 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/z3/2z39_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=2z39 ConSurf].
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== Publication Abstract from PubMed ==
Brassica juncea chitinase is an endo-acting, pathogenesis-related protein that is classified into glycoside hydrolase family 19, with highest homology (50-60%) in its catalytic domain to class I plant chitinases. Here we report X-ray structures of the chitinase catalytic domain from wild-type (apo, as well as with chloride ions bound) and a Glu234Ala mutant enzyme, solved by molecular replacement and refined at 1.53, 1.8 and 1.7 A resolution, respectively. Confirming our earlier mutagenesis studies, the active-site residues are identified as Glu212 and Glu234. Glu212 is believed to be the catalytic acid in the reaction, whereas Glu234 is thought to have a dual role, both activating a water molecule in its attack on the anomeric carbon, and stabilizing the charged intermediate. The molecules in the various structures differ significantly in the conformation of a number of loops that border the active-site cleft. The differences suggest an opening and closing of the enzyme during the catalytic cycle. Chitin is expected to dock first near Glu212, which will protonate it. Conformational changes then bring Glu234 closer, allowing it to assist in the following steps. These observations provide important insights into catalysis in family 19 chitinases.

Crystal structures of a family 19 chitinase from Brassica juncea show flexibility of binding cleft loops.,Ubhayasekera W, Tang CM, Ho SW, Berglund G, Bergfors T, Chye ML, Mowbray SL FEBS J. 2007 Jul;274(14):3695-703. Epub 2007 Jul 2. PMID:17608716<ref>PMID:17608716</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 2z39" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chitinase 3D structures|Chitinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Brassica juncea]]
[[Category: Large Structures]]
[[Category: Bergfors T]]
[[Category: Mowbray SL]]
[[Category: Ubhayasekera W]]