2wnz

Structure of the E192N mutant of E. coli N-acetylneuraminic acid lyase in complex with pyruvate in space group P21 crystal form I

spinqualitylabelsall models 2wnz, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2wnz is a 4 chain structure with sequence from Escherichia coli BL21(DE3). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.85Å Ligands: 2OP, ETX, KPI, LAC Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function NANA_ECOLI Catalyzes the cleavage of N-acetylneuraminic acid (sialic acid) to form pyruvate and N-acetylmannosamine via a Schiff base intermediate.[HAMAP-Rule:MF_01237] 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 The substrate specificity of Escherichia coli N-acetylneuraminic acid lyase was previously switched from the natural condensation of pyruvate with N-acetylmannosamine, yielding N-acetylneuraminic acid, to aldol condensation, generating N-alkylcarboxamide analogues of N-acetylneuraminic acid. This was achieved by a single mutation of Glu192 to Asn. In order to analyze the structural changes involved and to more fully understand the basis of this switch in specificity, we have isolated all 20 variants of the enzyme at position 192 and determined the activities with a range of substrates. We have also determined five high-resolution crystal structures: the structures of wild-type E. coli N-acetylneuraminic acid lyase in the presence and in the absence of pyruvate, the structures of the E192N variant in the presence and in the absence of pyruvate, and the structure of the E192N variant in the presence of pyruvate and a competitive inhibitor (2R,3R)-2,3,4-trihydroxy-N,N-dipropylbutanamide. All structures were solved in space group P2(1) at resolutions ranging from 1.65 A to 2.2 A. A comparison of these structures, in combination with the specificity profiles of the variants, reveals subtle differences that explain the details of the specificity changes. This work demonstrates the subtleties of enzyme-substrate interactions and the importance of determining the structures of enzymes produced by directed evolution, where the specificity determinants may change from one substrate to another. Structural Insights into Substrate Specificity in Variants of N-Acetylneuraminic Acid Lyase Produced by Directed Evolution.,Campeotto I, Bolt AH, Harman TA, Dennis C, Trinh CH, Phillips SE, Nelson A, Pearson AR, Berry A J Mol Biol. 2010 Sep 6. PMID:20826162 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also N-acetylneuraminate lyase 3D structures

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