1cgu

CATALYTIC CENTER OF CYCLODEXTRIN GLYCOSYLTRANSFERASE DERIVED FROM X-RAY STRUCTURE ANALYSIS COMBINED WITH SITE-DIRECTED MUTAGENESIS

spinqualitylabelsall models 1cgu, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1cgu is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA, GLC Activity: Cyclomaltodextrin glucanotransferase, with EC number 2.4.1.19 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 An X-ray structure analysis of a crystal of mutant Asp229----Ala of cyclodextrin glycosyltransferase from Bacillus circulans (Ec 2.4.1.19) that had been shortly exposed to beta-cyclodextrin showed density corresponding to a maltose bound at the catalytic center. The crystal structure was refined to an R-factor of 18.7% at 2.5-A resolution. The catalytic center is defined by homology with the structurally known alpha-amylases and by the observation that mutants Asp229----Ala and Asp328----Ala are almost inactive. By model building, the density-defined maltose was extended to a full beta-cyclodextrin, which then indicated the general locations of seven subsites for glucosyl units. The catalytically competent residues Asp229, Glu257, and Asp328 are at the reducing end of the density-defined maltose. In the unligated wild-type structure, Glu257 and Asp328 form a 2.6-A hydrogen bond between their carboxylates in an arrangement that resembles those of the catalytically competent carboxylates in acid proteases. Presumably, the first catalytic step is an attack of the proton between Glu257 and Asp328 on the oxygen of the glycosidic bond. Catalytic center of cyclodextrin glycosyltransferase derived from X-ray structure analysis combined with site-directed mutagenesis.,Klein C, Hollender J, Bender H, Schulz GE Biochemistry. 1992 Sep 22;31(37):8740-6. PMID:1390660 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glycosyltransferase

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