2gl9

Crystal Structure of Glycosylasparaginase-Substrate Complex

spinqualitylabelsall models 2gl9, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2gl9 is a 4 chain structure with sequence from Elizabethkingia meningoseptica. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: ASN, NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ASPG_ELIMR Cleaves the GlcNAc-Asn bond which joins oligosaccharides to the peptide of asparagine-linked glycoproteins. Requires that the glycosylated asparagine moiety is not substituted on its N-(R1) and C- (R2) terminus. 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 Glycosylasparaginase (GA) plays an important role in asparagine-linked glycoprotein degradation. A deficiency in the activity of human GA leads to a lysosomal storage disease named aspartylglycosaminuria. GA belongs to a superfamily of N-terminal nucleophile hydrolases that autoproteolytically generate their mature enzymes from inactive single chain protein precursors. The side-chain of the newly exposed N-terminal residue then acts as a nucleophile during substrate hydrolysis. By taking advantage of mutant enzyme of Flavobacterium meningosepticum GA with reduced enzymatic activity, we have obtained a crystallographic snapshot of a productive complex with its substrate (NAcGlc-Asn), at 2.0 A resolution. This complex structure provided us an excellent model for the Michaelis complex to examine the specific contacts critical for substrate binding and catalysis. Substrate binding induces a conformational change near the active site of GA. To initiate catalysis, the side-chain of the N-terminal Thr152 is polarized by the free alpha-amino group on the same residue, mediated by the side-chain hydroxyl group of Thr170. Cleavage of the amide bond is then accomplished by a nucleophilic attack at the carbonyl carbon of the amide linkage in the substrate, leading to the formation of an acyl-enzyme intermediate through a negatively charged tetrahedral transition state. Crystallographic snapshot of a productive glycosylasparaginase-substrate complex.,Wang Y, Guo HC J Mol Biol. 2007 Feb 9;366(1):82-92. Epub 2006 Sep 26. PMID:17157318 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Asparaginase 3D structures Glycosylasparaginase

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