Structure and function of α-glucan debranching enzymes

• Published in: Cellular and molecular life sciences : CMLS Vol. 73; no. 14; pp. 2619 - 2641
• Main Authors: Møller, Marie Sofie, Henriksen, Anette, Svensson, Birte
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-07-2016
• Subjects: Basic Medicine; Biochemistry; Biomedical and Life Sciences; Biomedicine; Carbohydrate binding modules; Cell and Molecular Biology; Cell Biology; Cell- och molekylärbiologi; Domain architecture; Glucans - metabolism; Glycogen - metabolism; Glycoside hydrolase family 13 subfamilies; Glycoside Hydrolases - chemistry; Glycoside Hydrolases - metabolism; Industry; Life Sciences; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinska och farmaceutiska grundvetenskaper; Multi-Author Review; Multi-domain three-dimensional structure; Phylogeny; Sequence motifs and determinants; Structural Homology, Protein; Structure–function relationship; Substrate specificity; Multi-domain three-dimensional structure; Carbohydrate binding modules; Glycoside hydrolase family 13 subfamilies; Substrate specificity; Structure–function relationship; Sequence motifs and determinants; Domain architecture; Phylogeny
• ISSN: 1420-682X; 1420-9071
• DOI: 10.1007/s00018-016-2241-y

α-Glucan debranching enzymes hydrolyse α-1,6-linkages in starch/glycogen, thereby, playing a central role in energy metabolism in all living organisms. They belong to glycoside hydrolase families GH13 and GH57 and several of these enzymes are industrially important. Nine GH13 subfamilies include α-glucan debranching enzymes; isoamylase and glycogen debranching enzymes (GH13_11); pullulanase type I/limit dextrinase (GH13_12–14); pullulan hydrolase (GH13_20); bifunctional glycogen debranching enzyme (GH13_25); oligo-1 and glucan-1,6-α-glucosidases (GH13_31); pullulanase type II (GH13_39); and α-amylase domains (GH13_41) in two-domain amylase–pullulanases. GH57 harbours type II pullulanases. Specificity differences, domain organisation, carbohydrate binding modules, sequence motifs, three-dimensional structures and specificity determinants are discussed. The phylogenetic analysis indicated that GH13_39 enzymes could represent a “missing link” between the strictly α-1,6-specific debranching enzymes and the enzymes with dual specificity and α-1,4-linkage preference.