5gqb: Difference between revisions
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The | ==Crystal structure of chitinase-h from O. furnacalis in complex with chitohepatose== | ||
<StructureSection load='5gqb' size='340' side='right'caption='[[5gqb]], [[Resolution|resolution]] 2.70Å' 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]] 2.7Å</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] | |||
<div style="background-color:#fffaf0;"> | |||
== 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®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 5gqb" style="background-color:#fffaf0;"></div> | ||
[[Category: | |||
[[Category: | ==See Also== | ||
[[Category: Zhou | *[[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]] | |||
Latest revision as of 14:39, 2 August 2023
Crystal structure of chitinase-h from O. furnacalis in complex with chitohepatoseCrystal structure of chitinase-h from O. furnacalis in complex with chitohepatose
Structural highlights
FunctionPublication Abstract from PubMedChitinase-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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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