Novel Catalytic Mechanism of Glycoside Hydrolysis Based on the Structure of an NAD+/Mn2+-Dependent Phospho-α-Glucosidase from Bacillus subtilis

• DOI: 10.1016/j.str.2004.06.020
• Publication Date: 2004-09-08T21:53:34Z
• Authors: Shyamala S. Rajan; Xiaojing Yang; Frank Collart; Vivian L.Y. Yip; Stephen G. Withers; Annabelle Varrot; John Thompson; Gideon J. Davies; Wayne F. Anderson
• Keywords: Models, Molecular; Manganese; 0303 health sciences; Binding Sites; L-Lactate Dehydrogenase; Molecular Structure; Protein Conformation; Molecular Sequence Data; alpha-Glucosidases; Crystallography, X-Ray; NAD; Recombinant Proteins; Substrate Specificity; 03 medical and health sciences; Bacterial Proteins; Structural Biology; Amino Acid Sequence; Glycosides; Molecular Biology; Sequence Alignment; Bacillus subtilis

GlvA, a 6-phospho-alpha-glucosidase from Bacillus subtilis, catalyzes the hydrolysis of maltose-6'-phosphate and belongs to glycoside hydrolase family GH4. GH4 enzymes are unique in their requirement for NAD(H) and a divalent metal for activity. We have determined the crystal structure of GlvA in complex with its ligands to 2.05 A resolution. Analyses of the active site architecture, in conjunction with mechanistic studies and precedent from the nucleotide diphosphate hexose dehydratases and other systems, suggest a novel mechanism of glycoside hydrolysis by GlvA that involves both the NAD(H) and the metal.