View source for 4hmd


==Crystal structure of cold-adapted chitinase from Moritella marina with a reaction intermediate - oxazolinium ion (NGO)==
<StructureSection load='4hmd' size='340' side='right'caption='[[4hmd]], [[Resolution|resolution]] 2.26&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hmd]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Moritella_marina Moritella marina]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HMD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HMD 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]] 2.26&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NGO:2-METHYL-4,5-DIHYDRO-(1,2-DIDEOXY-ALPHA-D-GLUCOPYRANOSO)[2,1-D]-1,3-OXAZOLE'>NGO</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=4hmd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hmd OCA], [https://pdbe.org/4hmd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hmd RCSB], [https://www.ebi.ac.uk/pdbsum/4hmd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hmd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B1VBB0_MORMI B1VBB0_MORMI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
X-ray crystallography reveals chitinase from the psychrophilic bacterium Moritella marina to be an elongated molecule which in addition to the catalytic beta/alpha-barrel domain contains two Ig-like domains and a chitin-binding domain, all linked in a chain. A ligand-binding study using NAG oligomers showed the enzyme to be active in the crystal lattice and resulted in complexes of the protein with oxazolinium ion (the reaction intermediate) and with NAG2, a reaction product. The characteristic motif DXDXE, containing three acidic amino-acid residues, which is a signature of type 18 chitinases, is conserved in the enzyme. Further analysis of the unliganded enzyme with the two protein-ligand complexes and a comparison with other known chitinases elucidated the roles of other conserved residues near the active site. Several features have been identified that are probably important for the reaction mechanism, substrate binding and the efficiency of the enzyme at low temperatures. The chitin-binding domain and the tryptophan patch on the catalytic domain provide general affinity for chitin, in addition to the affinity of the binding site; the two Ig-like domains give the protein a long reach over the chitin surface, and the flexible region between the chitin-binding domain and the adjacent Ig-like domain suggests an ability of the enzyme to probe the surface of the substrate, while the open shallow substrate-binding groove allows easy access to the active site.

Structure of a complete four-domain chitinase from Moritella marina, a marine psychrophilic bacterium.,Malecki PH, Raczynska JE, Vorgias CE, Rypniewski W Acta Crystallogr D Biol Crystallogr. 2013 May;69(Pt 5):821-9. doi:, 10.1107/S0907444913002011. Epub 2013 Apr 11. PMID:23633591<ref>PMID:23633591</ref>

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

==See Also==
*[[Chitinase 3D structures|Chitinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Moritella marina]]
[[Category: Malecki PH]]
[[Category: Raczynska JE]]
[[Category: Rypniewski W]]
[[Category: Vorgias CE]]