University of Groningen Structure-function relationships of family GH70 glucansucrase and 4,6-α-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes Meng, Xiangfeng; Gangoiti, Joana; Bai, Yuxiang; Pijning, Tjaard; Van Leeuwen, Sander S; Dijkhuizen, Lubbert Published in: Cellular and molecular life sciences DOI: 10.1007/s00018-016-2245-7 IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 2016 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Meng, X., Gangoiti, J., Bai, Y., Pijning, T., Van Leeuwen, S. S., & Dijkhuizen, L. (2016). Structure-function relationships of family GH70 glucansucrase and 4,6-α-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes. Cellular and molecular life sciences, 73(14), 2681-2706. https://doi.org/10.1007/s00018-016-2245-7 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date: 12-11-2019 Cell. Mol. Life Sci. (2016) 73:2681–2706 DOI 10.1007/s00018-016-2245-7 Cellular and Molecular Life Sciences MULTI-AUTHOR REVIEW Structure–function relationships of family GH70 glucansucrase and 4,6-a-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes 1 1 1 2 Xiangfeng Meng • Joana Gangoiti • Yuxiang Bai • Tjaard Pijning • 1 1 Sander S. Van Leeuwen • Lubbert Dijkhuizen Received: 21 April 2016 / Accepted: 22 April 2016 / Published online: 7 May 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract Lactic acid bacteria (LAB) are known to pro- applications in the food, medicine and cosmetic industries. duce large amounts of a-glucan exopolysaccharides. In this review, we summarize the microbiological distri- Family GH70 glucansucrase (GS) enzymes catalyze the bution and the structure–function relationships of family synthesis of these a-glucans from sucrose. The elucidation GH70 enzymes, introduce the two newly identified GH70 of the crystal structures of representative GS enzymes has subfamilies, and discuss evolutionary relationships advanced our understanding of their reaction mechanism, between family GH70 and GH13 enzymes. especially structural features determining their linkage specificity. In addition, with the increase of genome Keywords GH70 Á GH13 Á Glucansucrase Á sequencing, more and more GS enzymes are identified and 4,6-a-Glucanotransferase Á Structure–function Á Evolution characterized. Together, such knowledge may promote the synthesis of a-glucans with desired structures and proper- Abbreviations ties from sucrose. In the meantime, two new GH70 EPS Extracellular polysaccharides subfamilies (GTFB- and GTFC-like) have been identified GRAS Generally regarded as safe as 4,6-a-glucanotransferases (4,6-a-GTs) that represent GS Glucansucrase novel evolutionary intermediates between the family GH13 4,6-a-GTs 4,6-a-Glucanotransferases and ‘‘classical GH70 enzymes’’. These enzymes are not HMM High-molecular-mass active on sucrose; instead, they use (a1 ? 4) glucans (i.e. HPAEC-PAD High-performance anion-exchange malto-oligosaccharides and starch) as substrates to syn- chromatography equipped with an ED40 thesize novel a-glucans by introducing linear chains of pulsed amperometric detection (PAD) (a1 ? 6) linkages. All these GH70 enzymes are very system interesting biocatalysts and hold strong potential for IMMO Isomalto-/malto-oligosaccharide IMMP Isomalto-/malto-polysaccharide LAB Lactic acid bacteria LMM Low-molecular-mass Electronic supplementary material The online version of this article (doi:10.1007/s00018-016-2245-7) contains supplementary material, which is available to authorized users. & Lubbert Dijkhuizen Introduction [email protected] Lactic acid bacteria (LAB) are known to produce lactic 1 Microbial Physiology, Groningen Biomolecular Sciences and acid from sugar metabolism and have been used for the Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands production of traditional dairy products since ancient times. Nowadays, LAB are exploited as starter cultures to 2 Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, improve the preservation, nutritional values, taste and Nijenborgh 7, 9747, AG, Groningen, The Netherlands mouthfeel of fermented foods [1]. Various strains are also 123 2682 X. Meng et al. proven probiotics due to their beneficial effects on human Microbiological distribution of GH70 GS enzymes health [2]. LAB have the ‘‘generally regarded as safe’’ (GRAS) status, and are known to produce extracellular Sucrose, also known as table sugar, is one of the most polysaccharides (EPS) [3–6]. These EPS are likely abundant carbohydrates consumed in our daily life. It is a involved in the protection of LAB from harsh environ- disaccharide with the formula C12H22O11, consisting of the mental conditions such as desiccation, osmotic stress and monosaccharides glucose (D-glucopyranose) and fructose the presence of antimicrobial factors [6–8]. Some EPS (D-fructofuranose), linked by an (a1$b2) glycosidic link- facilitate the adhesion of bacterial cells to surfaces and, age. Early in 1861, Pasteur found a microorganism-derived thus, help LAB to colonize different environments substance being responsible for the gelification of sugar- through biofilm formation [6–8]. The EPS produced by cane syrups and it was named ‘‘dextran’’ [19, 20]. Van Streptococcus mutans are important pathogenic factors in Tiehem isolated this microorganism and named it as Leu- dental caries [9, 10]. These EPS have also found valuable conostoc mesenteroides in 1878 [19, 20]. An enzyme from applications in food and medicine, and in the cosmetic the cell-free supernatant was found to be responsible for industries [3–8]. As food supplements, EPS of LAB are the synthesis of dextran [21, 22]. Now, dextran is defined explored as texturizers, emulsifiers and viscosifiers and as a homopolysaccharide which is composed of D-glucose they also hold potential health beneficial effects as dietary residues with (a1 ? 6) linkages in the main chain and fiber and prebiotics [5, 7, 8]. Depending on their com- different degrees of (a1 ? 2) or (a1 ? 3) branched glu- position, EPS are divided into two groups: cosyl units. The GS enzyme that synthesizes dextran is heteropolysaccharides and homopolysaccharides [11]. named accordingly as dextransucrase (EC 2.4.1.5). Heteropolysaccharides of LAB contain different types of GSs are exclusively found in LAB, such as Leuconostoc, monosaccharides (e.g., glucose, galactose and rhamnose), Streptococcus, Lactobacillus and Weissella [15]. GSs are while homopolysaccharides of LAB consist of only one extracellular enzymes and depending on the particular type of monosaccharide (glucose or fructose). The bacterial source, they are produced either as cell wall-at- biosynthesis of heteropolysaccharides is complex and tached or free enzymes in culture fluids, or both [23–25]. A requires the combined action of a large number of pro- diversity of GSs has been characterized from various LAB teins including enzymes, transporters and regulators [11, and were found to produce a-glucans with all the possible 12]. Generally, Leloir glycosyltransferase enzymes are glycosidic linkages [(a1 ? 2), (a1 ? 3), (a1 ? 4) and involved that require expensive nucleotide-activated (a1 ? 6)], each enzyme with its own linkage specificity. sugars (e.g., UDP-glucose) [11, 12]. On the contrary, With the fast development of genome sequencing, the homopolysaccharides are generally synthesized from number of GSs annotated is rapidly increasing. By Nov. sucroseusingasingleglucansucrase (GS) or fructansu- 2015, 264 GSs had been annotated, including 57 charac- crase enzyme [13]. terized in the family GH70 of Carbohydrate-Active The GS enzymes of LAB belong to glycoside Enzymes Database (CAZy; see http://www.cazy.org). GSs hydrolase family 70 and catalyze the synthesis of a- are mainly found within the genera Leuconostoc (64 of glucan homopolysaccharides from sucrose [11, 14–16]. 264), Streptococcus (154 of 264), and Lactobacillus (23 of Recently, two new GH70 subfamilies have been estab- 264). Some GSs are also present in other LAB, i.e. Weis- lished, including the GTFB-like 4,6-a- sella (22 of 264) and Oenococcus (1 of 264). Some LAB glucanotransferases (GTFB-like 4,6-a-GTs) and GTFC- strains produce more than one GS enzyme. For example, like 4,6-a-glucanotransferases (GTFC-like 4,6-a-GTs) Streptococcus mutans, which is the main pathogen [17, 18]. They both synthesize novel a-glucans, but use responsible for dental caries, produces three distinct GSs (a1 ? 4) linked glucans (i.e. malto-oligosaccharides and (GTFB, GTFC and GTFD) (Table 1)[26,