3w4r | pdb_00003w4r

Crystal structure of an insect chitinase from the Asian corn borer, Ostrinia furnacalis

spinqualitylabelsall models 3w4r, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3w4r is a 1 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 1.7Å Ligands: NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q2V6H4_OSTFU Publication Abstract from PubMed Insects possess a greater number of chitinases than any other organisms. This work is the first report of unliganded and oligosaccharide-complexed crystal structures of the insect chitinase OfChtI from Ostrinia furnacalis, which is essential to moulting. The obtained crystal structures were solved at resolutions between 1.7 and 2.2 A. A structural comparison with other chitinases revealed that OfChtI contains a long substrate-binding cleft similar to the bacterial chitinase SmChiB from Serratia marcescens. However, unlike the exo-acting SmChiB, which has a blocked and tunnel-like cleft, OfChtI possesses an open and groove-like cleft. The complexed structure of the catalytic domain of OfChtI (OfChtI-CAD) with (GlcNAc)2/3 indicates that the reducing sugar at subsite -1 is in an energetically unfavoured `boat' conformation, a state that possibly exists just before the completion of catalysis. Because OfChtI is known to act from nonreducing ends, (GlcNAc)3 would be a hydrolysis product of (GlcNAc)6, suggesting that OfChtI possesses an endo enzymatic activity. Furthermore, a hydrophobic plane composed of four surface-exposed aromatic residues is adjacent to the entrance to the substrate-binding cleft. Mutations of these residues greatly impair the chitin-binding activity, indicating that this hydrophobic plane endows OfChtI-CAD with the ability to anchor chitin. This work reveals the unique structural characteristics of an insect chitinase. Structural characteristics of an insect group I chitinase, an enzyme indispensable to moulting.,Chen L, Liu T, Zhou Y, Chen Q, Shen X, Yang Q Acta Crystallogr D Biol Crystallogr. 2014 Apr 1;70(Pt 4):932-42. doi:, 10.1107/S1399004713033841. Epub 2014 Mar 19. PMID:24699639 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chitinase 3D structures

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