5y29: Difference between revisions
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<StructureSection load='5y29' size='340' side='right' caption='[[5y29]], [[Resolution|resolution]] 1.80Å' scene=''> | <StructureSection load='5y29' size='340' side='right' caption='[[5y29]], [[Resolution|resolution]] 1.80Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[5y29]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5Y29 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5Y29 FirstGlance]. <br> | <table><tr><td colspan='2'>[[5y29]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Asian_corn_borer Asian corn borer]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5Y29 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5Y29 FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5y29 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5y29 OCA], [http://pdbe.org/5y29 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5y29 RCSB], [http://www.ebi.ac.uk/pdbsum/5y29 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5y29 ProSAT]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5y29 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5y29 OCA], [http://pdbe.org/5y29 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5y29 RCSB], [http://www.ebi.ac.uk/pdbsum/5y29 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5y29 ProSAT]</span></td></tr> | ||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Chitin is a linear homopolymer of N-acetyl-beta-D-glucosamines and a major structural component of insect cuticles. Chitin hydrolysis involves glycoside hydrolase family 18 (GH18) chitinases. In insects, chitin hydrolysis is essential for periodic shedding of the old cuticle ecdysis and proceeds via a pathway different from that in the well-studied bacterial chitinolytic system. Group II chitinase (ChtII) is a widespread chitinolytic enzyme in insects and contains the greatest number of catalytic domains and chitin binding domains among chitinases. In Lepidopterans, ChtII and two other chitinases, ChtI and Chi-h, are essential for chitin hydrolysis. Although ChtI and Chi-h have been well studied, the role of ChtII remains elusive. Here, we investigated the structure and enzymology of OfChtII, a ChtII derived from the insect pest Ostrinia furnacalis We present the crystal structures of two catalytically active domains of OfChtII, OfChtII-C1 and OfChtII-C2, both in unliganded form and complexed with chitooligosaccharide substrates. We found that OfChtII-C1 and OfChtII-C2 both possess long, deep substrate-binding clefts with endochitinase activities. OfChtII exhibited structural characteristics within the substrate-binding cleft similar to those in OfChi-h and OfChtI. However, OfChtII lacked structural elements favoring substrate binding beyond the active sites, including an extra wall structure present in OfChi-h. Nevertheless, the numerous domains in OfChtII may compensate for this difference; a truncation containing one catalytic domain and three chitin binding modules (OfChtII-B4C1) displayed activity toward insoluble polymeric substrates that was higher than those of OfChi-h and OfChtI. Our observations provide the last piece of the puzzle of chitin hydrolysis in insects. | |||
Structural analysis of group II chitinase (ChtII) catalysis completes the puzzle of chitin hydrolysis in insects.,Chen W, Qu M, Zhou Y, Yang Q J Biol Chem. 2018 Jan 9. pii: RA117.000119. doi: 10.1074/jbc.RA117.000119. PMID:29317504<ref>PMID:29317504</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 5y29" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Asian corn borer]] | |||
[[Category: Chen, W]] | [[Category: Chen, W]] | ||
[[Category: Qu, M B]] | [[Category: Qu, M B]] | ||
Revision as of 23:52, 24 January 2018
Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1
Structural highlights
Publication Abstract from PubMedChitin is a linear homopolymer of N-acetyl-beta-D-glucosamines and a major structural component of insect cuticles. Chitin hydrolysis involves glycoside hydrolase family 18 (GH18) chitinases. In insects, chitin hydrolysis is essential for periodic shedding of the old cuticle ecdysis and proceeds via a pathway different from that in the well-studied bacterial chitinolytic system. Group II chitinase (ChtII) is a widespread chitinolytic enzyme in insects and contains the greatest number of catalytic domains and chitin binding domains among chitinases. In Lepidopterans, ChtII and two other chitinases, ChtI and Chi-h, are essential for chitin hydrolysis. Although ChtI and Chi-h have been well studied, the role of ChtII remains elusive. Here, we investigated the structure and enzymology of OfChtII, a ChtII derived from the insect pest Ostrinia furnacalis We present the crystal structures of two catalytically active domains of OfChtII, OfChtII-C1 and OfChtII-C2, both in unliganded form and complexed with chitooligosaccharide substrates. We found that OfChtII-C1 and OfChtII-C2 both possess long, deep substrate-binding clefts with endochitinase activities. OfChtII exhibited structural characteristics within the substrate-binding cleft similar to those in OfChi-h and OfChtI. However, OfChtII lacked structural elements favoring substrate binding beyond the active sites, including an extra wall structure present in OfChi-h. Nevertheless, the numerous domains in OfChtII may compensate for this difference; a truncation containing one catalytic domain and three chitin binding modules (OfChtII-B4C1) displayed activity toward insoluble polymeric substrates that was higher than those of OfChi-h and OfChtI. Our observations provide the last piece of the puzzle of chitin hydrolysis in insects. Structural analysis of group II chitinase (ChtII) catalysis completes the puzzle of chitin hydrolysis in insects.,Chen W, Qu M, Zhou Y, Yang Q J Biol Chem. 2018 Jan 9. pii: RA117.000119. doi: 10.1074/jbc.RA117.000119. PMID:29317504[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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