Abstract
α-Glucosidase hydrolyzes α-glucosides and transfers α-glucosyl residues to an acceptor through transglucosylation. In this study, GH13_31 α-glucosidase BspAG13_31A with high transglucosylation activity is reported in Bacillus sp. AHU2216 and biochemically and structurally characterized. This enzyme is specific to α-(1→4)-glucosidic linkage as substrates and transglucosylation products. Maltose is the most preferred substrate. Crystal structures of BspAG13_31A wild-type for the substrate-free form and inactive acid/base mutant E256Q in complexes with maltooligosaccharides were solved at 1.6–2.5 Å resolution. BspAG13_31A has a catalytic domain folded by an (β/α)8-barrel. In subsite +1, Ala200 and His203 on β→α loop 4 and Asn258 on β→α loop 5 are involved in the recognition of maltooligosaccharides. Structural basis for specificity of GH13_31 enzymes to α-(1→4)-glucosidic linkage is first described.
Original language | English |
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Pages (from-to) | 2268-2281 |
Number of pages | 14 |
Journal | FEBS Letters |
Volume | 592 |
Issue number | 13 |
DOIs | |
Publication status | Published - Jul 2018 |
Externally published | Yes |
Keywords
- glycoside hydrolase family 13
- transglycosylation
- α-glucosidase
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology