1xpy

Structural Basis for Catalytic Racemization and Substrate Specificity of an N-Acylamino Acid Racemase Homologue from Deinococcus radiodurans

spinqualitylabelsall models 1xpy, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1xpy is a 4 chain structure with sequence from Deinococcus radiodurans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MG, NLQ Related: 1r0m Resources: FirstGlance, OCA, RCSB, PDBsum 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 N-acylamino acid racemase (NAAAR) catalyzes the racemization of N-acylamino acids and can be used in concert with an aminoacylase to produce enantiopure alpha-amino acids, a process that has potential industrial applications. Here we have cloned and characterized an NAAAR homologue from a radiation-resistant ancient bacterium, Deinococcus radiodurans. The expressed NAAAR racemized various substrates at an optimal temperature of 60 degrees C and had Km values of 24.8 mM and 12.3 mM for N-acetyl-D-methionine and N-acetyl-L-methionine, respectively. The crystal structure of NAAAR was solved to 1.3 A resolution using multiwavelength anomalous dispersion (MAD) methods. The structure consists of a homooctamer in which each subunit has an architecture characteristic of enolases with a capping domain and a (beta/alpha)7 beta barrel domain. The NAAAR.Mg2+ and NAAAR.N-acetyl-L-glutamine.Mg2+ structures were also determined, allowing us to define the Lys170-Asp195-Glu220-Asp245-Lys269 framework for catalyzing 1,1-proton exchange of N-acylamino acids. Four subsites enclosing the substrate are identified: catalytic site, metal-binding site, side-chain-binding region, and a flexible lid region. The high conservation of catalytic and metal-binding sites in different enolases reflects the essentiality of a common catalytic platform, allowing these enzymes to robustly abstract alpha-protons of various carboxylate substrates efficiently. The other subsites involved in substrate recognition are less conserved, suggesting that divergent evolution has led to functionally distinct enzymes. Structural basis for catalytic racemization and substrate specificity of an N-acylamino acid racemase homologue from Deinococcus radiodurans.,Wang WC, Chiu WC, Hsu SK, Wu CL, Chen CY, Liu JS, Hsu WH J Mol Biol. 2004 Sep 3;342(1):155-69. PMID:15313614 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Leukotriene A4 Hydrolase

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