title: Structure-function relationships of family GH70 glucansucrase and 4,6-α-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes.
abstract: Lactic acid bacteria (LAB) are known to produce large amounts of α-glucan exopolysaccharides. Family GH70 glucansucrase (GS) enzymes catalyze the synthesis of these α-glucans from sucrose. The elucidation of the crystal structures of representative GS enzymes has advanced our understanding of their reaction mechanism, especially structural features determining their linkage specificity. In addition, with the increase of genome sequencing, more and more GS enzymes are identified and characterized. Together, such knowledge may promote the synthesis of α-glucans with desired structures and properties from sucrose. In the meantime, two new GH70 subfamilies (GTFB- and GTFC-like) have been identified as 4,6-α-glucanotransferases (4,6-α-GTs) that represent novel evolutionary intermediates between the family GH13 and "classical GH70 enzymes". These enzymes are not active on sucrose; instead, they use (α1 → 4) glucans (i.e. malto-oligosaccharides and starch) as substrates to synthesize novel α-glucans by introducing linear chains of (α1 → 6) linkages. All these GH70 enzymes are very interesting biocatalysts and hold strong potential for applications in the food, medicine and cosmetic industries. In this review, we summarize the microbiological distribution and the structure-function relationships of family GH70 enzymes, introduce the two newly identified GH70 subfamilies, and discuss evolutionary relationships between family GH70 and GH13 enzymes.
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Meng
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands.
authors.forename: Joana
authors.initials: J
authors.lastname: Gangoiti
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands.
authors.forename: Tjaard
authors.initials: T
authors.lastname: Pijning
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands.
authors.forename: Sander S
authors.initials: SS
authors.lastname: Van Leeuwen
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands. l.dijkhuizen@rug.nl.
authors.forename: Lubbert
authors.initials: L
authors.lastname: Dijkhuizen
mesh_terms: D001419:Bacteria / Q000201:enzymology; D055162:Biocatalysis; D019143:Evolution, Molecular; D006004:Glycogen Debranching Enzyme System / Q000737:chemistry* / Q000378:metabolism*; D016695:Glycosyltransferases / Q000737:chemistry* / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D006004:Glycogen Debranching Enzyme System; D016695:Glycosyltransferases; C033837:alternansucrase; C020569:4 alpha-glucanotransferase
keywords: 4,6-α-Glucanotransferase; Evolution; GH13; GH70; Glucansucrase; Structure–function