5y2a

Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 2

spinqualitylabelsall models 5y2a, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5y2a is a 2 chain structure with sequence from Ostrinia furnacalis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: MAN, NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A221ZS22_OSTFU 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chitinase 3D structures

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