5xsv

Crystal structure of an archaeal chitinase in the ligand-free form

spinqualitylabelsall models 5xsv, resolution 3.72Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5xsv is a 4 chain structure with sequence from Thermococcus chitonophagus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.723Å Ligands: CO, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A161KIT4_9EURY Publication Abstract from PubMed Chitinase D (designated as Pc-ChiD) was found in a hyperthermophilic archaeon, Pyrococcus chitonophagus (previously described as Thermococcus chitonophagus), that was isolated from media containing only chitin as carbon source. Pc-ChiD displays chitinase activity and is thermostable at temperatures up to 95 degrees C, suggesting its potential for industrial use. Pc-ChiD has a secretion signal peptide and two chitin-binding domains (ChBDs) in the N-terminal domain. However, the C-terminal domain shares no sequence similarity with previously identified saccharide-degrading enzymes and does not contain the DXDXE motif conserved in the glycoside hydrolase (GH) 18 family chitinases. To elucidate its overall structure and reaction mechanism, we determined the first crystal structures of Pc-ChiD, both in the ligand-free form and in complexes with substrates. Structure analyses revealed that the C-terminal domain of Pc-ChiD, Pc-ChiD(DeltaBD), consists of a third putative substrate-binding domain, which cannot be predicted from the amino acid sequence, and a catalytic domain structurally similar to that found in not the GH18 family but the GH23 family. Based on the similarity with GH23 family chitinase, the catalytic residues of Pc-ChiD were predicted and confirmed by mutagenesis analyses. Moreover, the specific C-terminal 100 residues of Pc-ChiD are important to fix the putative substrate-binding domain next to the catalytic domain, contributing to the structure stability as well as the long chitin chain binding. Our findings reveal the structure of a unique archaeal chitinase that is distinct from previously known members of the GH23 family. Crystal structures of an archaeal chitinase ChiD and its ligand complexes.,Nishitani Y, Horiuchi A, Aslam M, Kanai T, Atomi H, Miki K Glycobiology. 2018 Jun 1;28(6):418-426. doi: 10.1093/glycob/cwy024. PMID:29800365 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chitinase 3D structures

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