View source for 5gqb


==Crystal structure of chitinase-h from O. furnacalis in complex with chitohepatose==
<StructureSection load='5gqb' size='340' side='right'caption='[[5gqb]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5gqb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ostrinia_furnacalis Ostrinia furnacalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GQB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5GQB 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GCS:D-GLUCOSAMINE'>GCS</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=5gqb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5gqb OCA], [https://pdbe.org/5gqb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5gqb RCSB], [https://www.ebi.ac.uk/pdbsum/5gqb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5gqb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q4AE59_OSTFU Q4AE59_OSTFU] 
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== Publication Abstract from PubMed ==
Chitinase-h (Chi-h) is of special interest among insect chitinases due to its exclusive distribution in lepidopteran insects and high sequence identity with bacterial and baculovirus homologs. Here OfChi-h, a Chi-h from Ostrinia furnacalis, was investigated. Crystal structures of both OfChi-h and its complex with chitoheptaose ((GlcN)7) reveal that OfChi-h possesses a long and asymmetric substrate binding cleft, which is a typical characteristics of a processive exo-chitinase. The structural comparison between OfChi-h and its bacterial homolog SmChiA uncovered two phenylalanine-to-tryptophan site variants in OfChi-h at subsites +2 and possibly -7. The F232W/F396W double mutant endowed SmChiA with higher hydrolytic activities toward insoluble substrates, such as insect cuticle, alpha-chitin, and chitin nanowhisker. An enzymatic assay demonstrated that OfChi-h outperformed OfChtI, an insect endo-chitinase, toward the insoluble substrates, but showed lower activity toward the soluble substrate ethylene glycol chitin. Furthermore, OfChi-h was found to be inhibited by N,N',N''-trimethylglucosamine-N,N',N'',N'''-tetraacetylchitotetraose (TMG-(GlcNAc)4), a substrate analog which can be degraded into TMG-(GlcNAc)1-2 Injection of TMG-(GlcNAc)4 into 5th-instar O. furnacalis larvae led to severe defects in pupation. This work provides insights into a molting-indispensable insect chitinase that is phylogenetically closer to bacterial chitinases than insect chitinases.

Structure, Catalysis, and Inhibition of OfChi-h, the Lepidoptera-exclusive Insect Chitinase.,Liu T, Chen L, Zhou Y, Jiang X, Duan Y, Yang Q J Biol Chem. 2017 Feb 10;292(6):2080-2088. doi: 10.1074/jbc.M116.755330. Epub, 2017 Jan 4. PMID:28053084<ref>PMID:28053084</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 5gqb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chitinase 3D structures|Chitinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Ostrinia furnacalis]]
[[Category: Chen L]]
[[Category: Liu T]]
[[Category: Yang Q]]
[[Category: Zhou Y]]