View source for 1nwt


==Crystal structure of human cartilage gp39 (HC-gp39) in complex with chitopentaose==
<StructureSection load='1nwt' size='340' side='right'caption='[[1nwt]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1nwt]] is a 4 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=1NWT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NWT 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</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=1nwt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nwt OCA], [https://pdbe.org/1nwt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1nwt RCSB], [https://www.ebi.ac.uk/pdbsum/1nwt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1nwt ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/CH3L1_HUMAN CH3L1_HUMAN] A genetic variation in CHI3L1 is associated with susceptibility to asthma-related traits type 7 (ASRT7) [MIM:[https://omim.org/entry/611960 611960]. Asthma-related traits include clinical symptoms of asthma, such as coughing, wheezing and dyspnea, bronchial hyperresponsiveness (BHR) as assessed by methacholine challenge test, serum IgE levels, atopy, and atopic dermatitis.
== Function ==
[https://www.uniprot.org/uniprot/CH3L1_HUMAN CH3L1_HUMAN] Carbohydrate-binding lectin with a preference for chitin. May play a role in defense against pathogens, or in tissue remodeling. May play an important role in the capacity of cells to respond to and cope with changes in their environment.<ref>PMID:9492324</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/nw/1nwt_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=1nwt ConSurf].
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== Publication Abstract from PubMed ==
The human cartilage glycoprotein-39 (HCgp-39 or YKL40) is expressed by synovial cells and macrophages during inflammation. Its precise physiological role is unknown. However, it has been proposed that HCgp-39 acts as an autoantigen in rheumatoid arthritis, and high expression levels have been associated with cancer development. HCgp-39 shares high sequence homology with family 18 chitinases, and although it binds to chitin it lacks enzymatic activity. The crystal structure of HCgp-39 shows that the protein displays a (beta/alpha)8-barrel fold with an insertion of an alpha + beta domain. A 43-A long carbohydrate-binding cleft is present at the C-terminal side of the beta-strands in the (beta/alpha)8 barrel. Binding of chitin fragments of different lengths identified nine sugar-binding subsites in the groove. Protein-carbohydrate interactions are mainly mediated by stacking of side chains of aromatic amino acid residues. Surprisingly, the specificity of chitin binding to HCgp-39 depends on the length of the oligosaccharide. Although chitin disaccharides tend to occupy the distal subsites, longer chains bind preferably to the central subsites in the groove. Despite the absence of enzymatic activity, long chitin fragments are distorted upon binding, with the GlcNAc at subsite -1 in a boat conformation, similar to what has been observed in chitinases. The presence of chitin in the human body has never been documented so far. However, the binding features observed in the complex structures suggest that either chitin or a closely related oligosaccharide could act as the physiological ligand for HCgp-39.

Crystal structure and carbohydrate-binding properties of the human cartilage glycoprotein-39.,Fusetti F, Pijning T, Kalk KH, Bos E, Dijkstra BW J Biol Chem. 2003 Sep 26;278(39):37753-60. Epub 2003 Jul 8. PMID:12851408<ref>PMID:12851408</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 1nwt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chitinase-3-like protein 3D structures|Chitinase-3-like protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Bos E]]
[[Category: Dijkstra BW]]
[[Category: Fusetti F]]
[[Category: Kalk KH]]
[[Category: Pijning T]]