2pwg
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Crystal Structure of the Trehalulose Synthase MutB From Pseudomonas Mesoacidophila MX-45 Complexed to the Inhibitor Castanospermine
OverviewOverview
Various diseases related to the over- consumption of sugar make a growing, need for sugar substitutes. Since sucrose is an inexpensive and readily, available D-glucose donor, the industrial potential for enzymatic, synthesis of the sucrose isomers trehalulose and/or isomaltulose from, sucrose is large. The product specificity of sucrose isomerases which, catalyze this reaction depends essentially on the possibility for, tautomerization of sucrose which is required for trehalulose formation., For optimal use of the enzyme, targeting controlled synthesis of these, functional isomers, it is necessary to minimize the side reactions. This, requires an extensive analysis of substrate binding modes and of the, specificity- determining sites in the structure. The 1.6 to 2.2 A, resolution three-dimensional structures of native and mutant complexes of, a trehalulose synthase from Pseudomonas mesoacidophila MX-45 mimic, successive states of the enzyme reaction. Combined with mutagenesis, studies they give for the first time thorough insights into substrate, recognition and processing, and reaction specificities of these enzymes., Amongst the important outcomes of this study is the revelation of an, aromatic clamp defined by Phe256 and Phe280 playing an essential role in, substrate recognition and in controlling the reaction specificity, which, is further supported by mutagenesis studies. Furthermore, this study, highlights essential residues for binding the glucosyl- and, fructosyl-moieties. The introduction of subtle changes informed by, comparative 3D structural data observed within our study can lead to, fundamental modifications in the mode of action of sucrose isomerases, and, hence provide a templatefor industrial catalysts.
About this StructureAbout this Structure
2PWG is a Single protein structure of sequence from Pseudomonas mesoacidophila with and as ligands. Active as Isomaltulose synthase, with EC number 5.4.99.11 Full crystallographic information is available from OCA.
ReferenceReference
Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization., Ravaud S, Robert X, Watzlawick H, Haser R, Mattes R, Aghajari N, J Biol Chem. 2007 Jun 27;. PMID:17597061
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