5gxx

Crystal structure of endoglucanase CelQ from Clostridium thermocellum complexed with Tris

spinqualitylabelsall models 5gxx, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5gxx is a 2 chain structure with sequence from Acetivibrio thermocellus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: CA, CL, TRS Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9AJF8_ACETH Publication Abstract from PubMed Endoglucanase CtCel9Q is one of the enzyme components of the cellulosome, which is an active cellulase system in the thermophile Clostridium thermocellum. The precursor form of CtCel9Q comprises a signal peptide, a glycoside hydrolase family 9 catalytic domain, a type 3c carbohydrate-binding module (CBM), and a type I dockerin domain. Here, we report the crystal structures of C-terminally truncated CtCel9Q (CtCel9QDeltac) complexed with Tris, Tris+cellobiose, cellobiose+cellotriose, cellotriose, and cellotetraose at resolutions of 1.50, 1.70, 2.05, 2.05 and 1.75 A, respectively. CtCel9QDeltac forms a V-shaped homodimer through residues Lys529-Glu542 on the type 3c CBM, which pairs two beta-strands (beta4 and beta5 of the CBM). In addition, a disulfide bond was formed between the two Cys535 residues of the protein monomers in the asymmetric unit. The structures allow the identification of four minus (-) subsites and two plus (+) subsites; this is important for further understanding the structural basis of cellulose binding and hydrolysis. In the oligosaccharide-free and cellobiose-bound CtCel9QDeltac structures, a Tris molecule was found to be bound to three catalytic residues of CtCel9Q and occupied subsite -1 of the CtCel9Q active-site cleft. Moreover, the enzyme activity assay in the presence of 100 mm Tris showed that the Tris almost completely suppressed CtCel9Q hydrolase activity. Crystal Structures of the C-Terminally Truncated Endoglucanase Cel9Q from Clostridium thermocellum Complexed with Cellodextrins and Tris.,Jeng WY, Liu CI, Lu TJ, Lin HJ, Wang NC, Wang AH Chembiochem. 2019 Jan 18;20(2):295-307. doi: 10.1002/cbic.201800789. Epub 2019, Jan 14. PMID:30609216 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glucanase 3D structures

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