1qi0

ENDOGLUCANASE CEL5A FROM BACILLUS AGARADHAERENS IN THE TETRAGONAL CRYSTAL FORM IN COMPLEX WITH CELLOBIOSE

spinqualitylabelsall models 1qi0, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1qi0 is a 1 chain structure with sequence from Salipaludibacillus agaradhaerens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: BGC, CA, PRD_900005 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GUN5_SALAG Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Glycoside hydrolases are ubiquitous enzymes involved in a diverse array of biological processes, from the breakdown of biomass, through to viral invasion and cellular signalling. Endoglucanase Cel5A from Bacillus agaradhaerens, classified into glycoside hydrolase family 5, has been studied in a catalytically inactive crystal form at low pH conditions, in which native and complex structures revealed the importance of ring distortion during catalysis. Here, we present the structure of Cel5A in a new crystal form obtained at higher pH values in which the enzyme is active "in-crystal". Native, cellotriosyl-enzyme intermediate and beta-d-cellobiose structures were solved at 1.95, 1.75 and 2.1 A resolution, respectively. These structures reveal two classes of conformational change: those caused by crystal-packing and pH, with others induced upon substrate binding. At pH 7 a histidine residue, His206, implicated in substrate-binding and catalysis, but previously far removed from the substrate-binding cleft, moves over 10 A into the active site cleft in order to interact with the substrate in the +2 subsite. Occupation of the -1 subsite by substrate induces a loop closure to optimise protein-ligand interactions. Cel5A, along with the unrelated family 45 and family 6 cellulases, provides further evidence of substantial conformational change in response to ligand binding for this class of hydrolytic enzyme. Insights into ligand-induced conformational change in Cel5A from Bacillus agaradhaerens revealed by a catalytically active crystal form.,Varrot A, Schulein M, Davies GJ J Mol Biol. 2000 Mar 31;297(3):819-28. PMID:10731432 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glucanase 3D structures

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