4fls

Crystal structure of Amylosucrase inactive double mutant F290K-E328Q from Neisseria polysaccharea in complex with sucrose.

spinqualitylabelsall models 4fls, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4fls is a 1 chain structure with sequence from Neisseria polysaccharea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CL, FRU, GLC, GOL, PRD_900003 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AMYS_NEIPO Catalyzes the synthesis of alpha-glucan from sucrose. Catalyzes, in addition, sucrose hydrolysis, maltose and maltotriose synthesis by successive transfers of the glucosyl moiety of sucrose onto the released glucose, and finally turanose and trehalulose synthesis, these two sucrose isomers being obtained by glucosyl transfer onto fructose. Publication Abstract from PubMed Iterative saturation mutagenesis and combinatorial active site saturation focused on vicinal amino acids were used to alter the acceptor specificity of amylosucrase from Neisseria polysaccharea , a sucrose-utilizing alpha-transglucosidase, and sort out improved variants. From the screening of three semirational sublibraries accounting in total for 20 000 variants, we report here the isolation of three double mutants of N. polysaccharea amylosucrase displaying a spectacular specificity enhancement toward both sucrose, the donor substrate, and the allyl 2-acetamido-2-deoxy-alpha-d-glucopyranoside acceptor as compared to the wild-type enzyme. Such levels of activity improvement have never been reported before for this class of carbohydrate-active enzymes. X-ray structure of the best performing enzymes supported by molecular dynamics simulations showed local rigidity of the -1 subsite as well as flexibility of loops involved in active site topology, which both account for the enhanced catalytic performances of the mutants. The study well illustrates the importance of taking into account the local conformation of catalytic residues as well as protein dynamics during the catalytic process, when designing enzyme libraries. Applying pairwise combinations of amino Acid mutations for sorting out highly efficient glucosylation tools for chemo-enzymatic synthesis of bacterial oligosaccharides.,Champion E, Guerin F, Moulis C, Barbe S, Tran TH, Morel S, Descroix K, Monsan P, Mourey L, Mulard LA, Tranier S, Remaud-Simeon M, Andre I J Am Chem Soc. 2012 Nov 14;134(45):18677-88. doi: 10.1021/ja306845b. Epub 2012, Oct 30. PMID:23072374 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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