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Structural determinants of product specificity of sucrose isomerases
Author(s) -
Ravaud Stéphanie,
Robert Xavier,
Watzlawick Hildegard,
Haser Richard,
Mattes Ralf,
Aghajari Nushin
Publication year - 2009
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2009.05.002
Subject(s) - isomerase , sucrose , biochemistry , chemistry , enzyme , substrate (aquarium) , biology , ecology
The healthy sweetener isomaltulose is industrially produced from the conversion of sucrose by the sucrose isomerase SmuA from Protaminobacter rubrum . Crystal structures of SmuA in native and deoxynojirimycin complexed forms completed with modeling studies unravel the characteristics of the isomaltulose synthases catalytic pocket and their substrate binding mode. Comparison with the trehalulose synthase MutB highlights the role of Arg 298 and Arg 306 active site residues and surface charges in controlling product specificity of sucrose isomerases (isomaltulose versus trehalulose). The results provide a rationale for the specific design of optimized enzymes.