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Dong J, Abou Hachem M, Wang Y, Li X, Zhang B, Pijning T, Svensson B, Dijkhuizen L, Jin Z, Bai Y. Tailor-Made α-Glucans by Engineering the Processivity of α-Glucanotransferases via Tunnel-Cleft Active Center Interconversions. J Agric Food Chem 2024; 72:11041-11050. [PMID: 38700846 DOI: 10.1021/acs.jafc.4c01842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The function of polysaccharides is intimately associated with their size, which is largely determined by the processivity of transferases responsible for their synthesis. A tunnel active center architecture has been recognized as a key factor that governs processivity of several glycoside hydrolases (GHs), e.g., cellulases and chitinases. Similar tunnel architecture is also observed in the Limosilactobacillus reuteri 121 GtfB (Lr121 GtfB) α-glucanotransferase from the GH70 family. The molecular element underpinning processivity of these transglucosylases remains underexplored. Here, we report the synthesis of the smallest (α1 → 4)-α-glucan interspersed with linear and branched (α1 → 6) linkages by a novel 4,6-α-glucanotransferase from L. reuteri N1 (LrN1 GtfB) with an open-clefted active center instead of the tunnel structure. Notably, the loop swapping engineering of LrN1 GtfB and Lr121 GtfB based on their crystal structures clarified the impact of the loop-mediated tunnel/cleft structure at the donor subsites -2 to -3 on processivity of these α-glucanotransferases, enabling the tailoring of both product sizes and substrate preferences. This study provides unprecedented insights into the processivity determinants and evolutionary diversification of GH70 α-glucanotransferases and offers a simple route for engineering starch-converting α-glucanotransferases to generate diverse α-glucans for different biotechnological applications.
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Affiliation(s)
- Jingjing Dong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Maher Abou Hachem
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Yanli Wang
- College of Food Sciences and Engineering, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Xiaoxiao Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Bo Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Tjaard Pijning
- Biomolecular X-ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG Groningen, The Netherlands
| | - Birte Svensson
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Lubbert Dijkhuizen
- Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG Groningen, The Netherlands
- CarbExplore Research BV, 9747 AA Groningen, The Netherlands
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
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Dong J, Bai Y, Chen Y, Li X, Wang Y, Fan R, Wang N, Jin Z. Identification of a novel starch-converting GtfB enzyme from the Fructilactobacillus sanfranciscensis TMW11304 to reduce the viscoelasticity and retrogradation of tapioca starch. Int J Biol Macromol 2024; 263:130308. [PMID: 38401578 DOI: 10.1016/j.ijbiomac.2024.130308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/28/2024] [Accepted: 02/18/2024] [Indexed: 02/26/2024]
Abstract
Starch-converting α-glucanotransferases are efficient enzymatic toolkits for the biosynthesis of diverse α-glucans, which hold vast application potential in the food industry. In this work, we identified a novel GtfB protein from Fructilactobacillus sanfranciscensis TMW11304 (FsTMW11304 GtfB) in NCBI. Although this enzyme was highly conserved in motifs I-IV with those isomalto-maltopolysaccharides (IMMPs)-producing GtfB α-glucanotransferases, it possessed distinct deletions and mutations in two crucial loops shaping the active site. Hence, unlike those GtfB enzymes, FsTMW11304 GtfB not only exhibited excellent 4,6-α-glucanotransferase activity on amylose to generate atypically low-molecular-weight IMMPs with consecutive linear (α1 → 6) linkages up to 48 %, but also held good capability towards branched substrates. Besides, compared with the control, the treatment by FsTMW11304 GtfB reduced the storage/loss modulus of granular and gelatinized tapioca starches (TS) by 12.0 %/17.9 % and 91.4 %/82.9 %, respectively, indicating that the rigidity of the gel structure was attenuated to different degrees in the two reaction systems. Furthermore, the setback viscosity observed in the gelatinized TS modified by FsTMW11304 GtfB was only 5 % of that observed in the control group, suggesting the short-term anti-retrogradation property has been substantially improved. Thus, FsTMW11304 GtfB represents a meaningful addition to the α-glucanotransferases in GH70 family, which expands the repertoire of diverse α-glucans synthesized from starch and facilitates the understanding of the structure-function relationship of the GtfB α-glucanotransferases.
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Affiliation(s)
- Jingjing Dong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Ying Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiaoxiao Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yanli Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Rui Fan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Nana Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China.
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Wang N, Dong J, Li X, Svensson B, Jin Z, Bai Y. N1019D Mutant of Limosilactobacillus reuteri 121 4,6-α-Glucanotransferase GtfB Significantly Improved Catalytic Activity. J Agric Food Chem 2024; 72:6509-6518. [PMID: 38488047 DOI: 10.1021/acs.jafc.4c00540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Limosilactobacillus reuteri 121 4,6-α-glucanotransferase GtfB (Lr 121 GtfB), belonging to glycoside hydrolase family 70 (GH70), synthesizes linear isomalto/malto polysaccharides having (α1→6) linkages attached to the nonreducing ends of (α1→4) linked maltose oligosaccharide segments using starch or maltodextrin as a substrate. Since Lr 121 GtfB has low catalytic activity and efficiency, it leads to substrate regeneration and reduced substrate utilization. In this study, we superimposed the crystal structure of Lr 121 GtfB-ΔNΔV with that of L. reuteri NCC 2613 GtfB-ΔNΔV (Lr 2613 GtfB-ΔNΔV) to identify the acceptor binding subsites +1 to +3 and constructed five single-residue mutants and a random mutagenesis of N1019. Compared with the wild-type, N1019D Lr 121 GtfB-ΔN did not alter the product specificity, increased the catalytic activity and efficiency by 420 and 590%, respectively, and maintained >80% relative activity in the pH 3.5-6.5 interval. The findings will contribute to the industrial application of Lr 121 GtfB and provide new solutions for starch synthesis of higher value derivatives.
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Affiliation(s)
- Nana Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Jingjing Dong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiaoxiao Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Birte Svensson
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
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Dong J, Bai Y, Wang Q, Chen Q, Li X, Wang Y, Ji H, Meng X, Pijning T, Svensson B, Dijkhuizen L, Abou Hachem M, Jin Z. Insights into the Structure-Function Relationship of GH70 GtfB α-Glucanotransferases from the Crystal Structure and Molecular Dynamic Simulation of a Newly Characterized Limosilactobacillus reuteri N1 GtfB Enzyme. J Agric Food Chem 2024; 72:5391-5402. [PMID: 38427803 DOI: 10.1021/acs.jafc.4c00104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
α-Glucanotransferases of the CAZy family GH70 convert starch-derived donors to industrially important α-glucans. Here, we describe characteristics of a novel GtfB-type 4,6-α-glucanotransferase of high enzyme activity (60.8 U mg-1) from Limosilactobacillus reuteri N1 (LrN1 GtfB), which produces surprisingly large quantities of soluble protein in heterologous expression (173 mg pure protein per L of culture) and synthesizes the reuteran-like α-glucan with (α1 → 6) linkages in linear chains and branch points. Protein structural analysis of LrN1 GtfB revealed the potential crucial residues at subsites -2∼+2, particularly H265, Y214, and R302, in the active center as well as previously unidentified surface binding sites. Furthermore, molecular dynamic simulations have provided unprecedented insights into linkage specificity hallmarks of the enzyme. Therefore, LrN1 GtfB represents a potent enzymatic tool for starch conversion, and this study promotes our knowledge on the structure-function relationship of GH70 GtfB α-glucanotransferases, which might facilitate the production of tailored α-glucans by enzyme engineering in future.
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Affiliation(s)
- Jingjing Dong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Qin Wang
- Department of Biochemistry and Molecular Biology, Binzhou Medical University, YanTai, Shandong 264003, China
| | - Qiuming Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiaoxiao Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yanli Wang
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Hangyan Ji
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China
| | - Tjaard Pijning
- Biomolecular X-ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG Groningen, The Netherlands
| | - Birte Svensson
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Lubbert Dijkhuizen
- Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG Groningen, The Netherlands
- CarbExplore Research BV, 9747 AA Groningen, The Netherlands
| | - Maher Abou Hachem
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
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Dong J, Bai Y, Fan R, Li X, Wang Y, Chen Y, Wang Q, Jin Z. Exploring a GtfB-Type 4,6-α-Glucanotransferase to Synthesize the (α1 → 6) Linkages in Linear Chain and Branching Points from Amylose and Enhance the Functional Property of Granular Corn Starches. J Agric Food Chem 2024; 72:2287-2299. [PMID: 38231152 DOI: 10.1021/acs.jafc.3c08425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Starch-converting α-glucanotransferases of glycoside hydrolase family 70 (GH70) are promising enzymatic tools for the production of diverse α-glucans with (potential) commercial applications in food and health and as biomaterials. In this study, a novel GtfB enzyme from Weissella confusa MBF8-1 was screened in the National Center for Biotechnology Information (NCBI) nonredundant protein database. The enzyme (named WcMBF8-1 GtfB) displayed high conservation in motifs I-IV with other GtfB enzymes but possessed unique variations in several substrate-binding residues. Structural characterizations of its α-glucan products revealed that WcMBF8-1 GtfB exhibited an atypical 4,6-α-glucanotransferase activity and was capable of catalyzing, by cleaving off (α1 → 4)-linkages in starch-like substrates and the synthesis of linear (α1 → 6) linkages and (α1 → 4,6) branching points. The product specificity enlarges the diversity of α-glucans and facilitates recognition of the determinants of the linkage specificity in GtfB enzymes. Furthermore, the contents of slowly digestible starch and resistant starch of granular corn starches, modified by WcMBF8-1 GtfB, increased by 6.7%, which suggested the potential value for the utilization of WcMBF8-1 GtfB to prepare "clean-label" starch ingredients with improved functional attributes.
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Affiliation(s)
- Jingjing Dong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Rui Fan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiaoxiao Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yanli Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Ying Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Qin Wang
- Department of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, Shandong 264003, China
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
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Schormann N, Patel M, Thannickal L, Purushotham S, Wu R, Mieher JL, Wu H, Deivanayagam C. The catalytic domains of Streptococcus mutans glucosyltransferases: a structural analysis. Acta Crystallogr F Struct Biol Commun 2023; 79:119-127. [PMID: 37158310 PMCID: PMC10167749 DOI: 10.1107/s2053230x23003199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/06/2023] [Indexed: 05/10/2023] Open
Abstract
Streptococcus mutans, found in the human oral cavity, is a significant contributor to the pathogenesis of dental caries. This bacterium expresses three genetically distinct types of glucosyltransferases named GtfB (GTF-I), GtfC (GTF-SI) and GtfD (GTF-S) that play critical roles in the development of dental plaque. The catalytic domains of GtfB, GtfC and GtfD contain conserved active-site residues for the overall enzymatic activity that relate to hydrolytic glycosidic cleavage of sucrose to glucose and fructose, release of fructose and generation of a glycosyl-enzyme intermediate in the reducing end. In a subsequent transglycosylation step, the glucosyl moiety is transferred to the nonreducing end of an acceptor to form a growing glucan polymer chain made up of glucose molecules. It has been proposed that both sucrose breakdown and glucan synthesis occur in the same active site of the catalytic domain, although the active site does not appear to be large enough to accommodate both functions. These three enzymes belong to glycoside hydrolase family 70 (GH70), which shows homology to glycoside hydrolase family 13 (GH13). GtfC synthesizes both soluble and insoluble glucans (α-1,3 and α-1,6 glycosidic linkages), while GtfB and GtfD synthesize only insoluble or soluble glucans, respectively. Here, crystal structures of the catalytic domains of GtfB and GtfD are reported. These structures are compared with previously determined structures of the catalytic domain of GtfC. With this work, apo structures and inhibitor-complex structures with acarbose are now available for the catalytic domains of GtfC and GtfB. The structure of GtfC with maltose allows further identification and comparison of active-site residues. A model of sucrose binding to GtfB is also included. The new structure of the catalytic domain of GtfD affords a structural comparison of the three S. mutans glycosyltransferases. Unfortunately, the catalytic domain of GtfD is not complete since crystallization resulted in the structure of a truncated protein lacking approximately 200 N-terminal residues of domain IV.
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Affiliation(s)
- Norbert Schormann
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Manisha Patel
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Luke Thannickal
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sangeetha Purushotham
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ren Wu
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Joshua L. Mieher
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hui Wu
- School of Dentistry, Oregon Health and Science University, Portland, OR 97201, USA
| | - Champion Deivanayagam
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Chatterjee S, Damle SG, Iyer N. A study on genetic and mutans streptococcal transmissibility of dental caries. J Oral Maxillofac Pathol 2022; 26:604. [PMID: 37082046 PMCID: PMC10112085 DOI: 10.4103/jomfp.jomfp_201_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 06/10/2022] [Accepted: 07/06/2022] [Indexed: 04/22/2023] Open
Abstract
Background Dental caries is characterized by an interplay between environmental and genetic factors. Aim The aim of this study was to analyse the transmissibilities of high caries risk chromosomal loci at 5q 12.1-13.3 and low caries risk chromosomal loci at 13q31.1 and Streptococcus mutans (S. mutans) in family units. Materials This prospective cohort study was performed on 56 families grouped into four: (a) Group I: 18 families of children with caries affected primary teeth; (b) Group II: 21 families of children with caries in permanent teeth; (c) Group III: 6 families of children with no caries in primary teeth and (d) Group IV: 12 families of children with no caries in permanent teeth. Blood, saliva and plaque samples were collected from consenting study participants. Isolated DNAs were subjected to polymerase chain reactions using suitable primers. Data collected was analysed with ANOVA and Chi-squared test. Results Wide expression of chromosome loci 5q12.1-13.3 was obtained in both blood and saliva samples. For chromosome loci 13q31.1, no expression was found in saliva samples, hence indicating its local absence. For the GtfB expression, transmissibility was common for a single band expressing S. mutans. Conclusion This study reflects upon newer findings in the field of genetic research on dental caries.
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Affiliation(s)
- Shailja Chatterjee
- Department of Oral and Maxillofacial Pathology, Yamuna Institute of Dental Sciences and Research, Yamuna Nagar, Haryana, India
| | - Satyawan G. Damle
- Former Vice-chancellor, M. M. (Deemed to be) University, Mullana, Ambala, Haryana, India
| | - Nageshwar Iyer
- Former Principal, MM College of Dental Sciences and Research, M. M. (Deemed to be) University, Mullana, Ambala, Haryana, India
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Pijning T, Gangoiti J, te Poele EM, Börner T, Dijkhuizen L. Insights into Broad-Specificity Starch Modification from the Crystal Structure of Limosilactobacillus Reuteri NCC 2613 4,6-α-Glucanotransferase GtfB. J Agric Food Chem 2021; 69:13235-13245. [PMID: 34708648 PMCID: PMC8587608 DOI: 10.1021/acs.jafc.1c05657] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 05/31/2023]
Abstract
GtfB-type α-glucanotransferase enzymes from glycoside hydrolase family 70 (GH70) convert starch substrates into α-glucans that are of interest as food ingredients with a low glycemic index. Characterization of several GtfBs showed that they differ in product- and substrate specificity, especially with regard to branching, but structural information is limited to a single GtfB, preferring mostly linear starches and featuring a tunneled binding groove. Here, we present the second crystal structure of a 4,6-α-glucanotransferase (Limosilactobacillus reuteri NCC 2613) and an improved homology model of a 4,3-α-glucanotransferase GtfB (L. fermentum NCC 2970) and show that they are able to convert both linear and branched starch substrates. Compared to the previously described GtfB structure, these two enzymes feature a much more open binding groove, reminiscent of and evolutionary closer to starch-converting GH13 α-amylases. Sequence analysis of 287 putative GtfBs suggests that only 20% of them are similarly "open" and thus suitable as broad-specificity starch-converting enzymes.
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Affiliation(s)
- Tjaard Pijning
- Biomolecular
X-ray Crystallography, Groningen Biomolecular Sciences and Biotechnology
Institute (GBB), University of Groningen, Nijenborgh 7, Groningen 9747 AG, The
Netherlands
| | - Joana Gangoiti
- Microbial
Physiology, Groningen Biomolecular Sciences and Biotechnology Institute
(GBB), University of Groningen, Nijenborgh 7, Groningen 9747 AG, The
Netherlands
| | - Evelien M. te Poele
- Microbial
Physiology, Groningen Biomolecular Sciences and Biotechnology Institute
(GBB), University of Groningen, Nijenborgh 7, Groningen 9747 AG, The
Netherlands
- CarbExplore
Research B.V., Zernikelaan
8, Groningen 9747 AA, The Netherlands
| | - Tim Börner
- Nestlé
Research, Société des Produits Nestlé SA, Route du Jorat 57, 1000 Lausanne, Switzerland
| | - Lubbert Dijkhuizen
- Microbial
Physiology, Groningen Biomolecular Sciences and Biotechnology Institute
(GBB), University of Groningen, Nijenborgh 7, Groningen 9747 AG, The
Netherlands
- CarbExplore
Research B.V., Zernikelaan
8, Groningen 9747 AA, The Netherlands
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Li X, Fei T, Wang Y, Zhao Y, Pan Y, Li D. Wheat Starch with Low Retrogradation Properties Produced by Modification of the GtfB Enzyme 4,6-α-Glucanotransferase from Streptococcus thermophilus. J Agric Food Chem 2018; 66:3891-3898. [PMID: 29582651 DOI: 10.1021/acs.jafc.8b00550] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A GtfB enzyme 4,6-α-glucanotransferase from Streptococcus thermophilus lacking 761 N-terminal amino acids was heterologously expressed in Escherichia coli. Purified S. thermophilus GtfB showed transglycosylation activities toward starch, resulting in branch points of (α1→6)-glycosidic linkages plus linear chains of (α1→4)-glycosidic linkages. After wheat starch was modified at a rate of 0.1 g/mL by 1-4 U/g starch GtfB at pH 6.0 and 40 °C for 1 h, the weight-averaged molecular weight decreased from 1.70 × 107 g/mol to 1.21 × 106 to 3.41 × 106 g/mol, the amylose content decreased from 22.07 to 16.34-17.11%, and that of amylopectin long-branch chains decreased from 26.4 to 10.25-15.64% ( P < 0.05). After the GtfB-modified wheat starches were gelatinized and stored at 4 °C for 1-2 weeks, their endothermic enthalpies were significantly lower than that of the control sample ( P < 0.05), indicating low retrogradation rates.
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Affiliation(s)
- Xiaolei Li
- Engineering Technological Center of Mushroom Industry and School of Biological Science and Biotechnology , Minnan Normal University , 36 Xianqianzhi Street , Zhangzhou 363000 , Fujian , People's Republic of China
- Key Laboratory of Agro-products Processing Technology at Jilin Provincial Universities , Changchun University , 6543 Weixing Road , Changchun 130022 , Jilin , People's Republic of China
| | - Teng Fei
- Key Laboratory of Agro-products Processing Technology at Jilin Provincial Universities , Changchun University , 6543 Weixing Road , Changchun 130022 , Jilin , People's Republic of China
| | - Yong Wang
- Key Laboratory of Agro-products Processing Technology at Jilin Provincial Universities , Changchun University , 6543 Weixing Road , Changchun 130022 , Jilin , People's Republic of China
| | - Yakun Zhao
- Key Laboratory of Agro-products Processing Technology at Jilin Provincial Universities , Changchun University , 6543 Weixing Road , Changchun 130022 , Jilin , People's Republic of China
| | - Yutian Pan
- Engineering Technological Center of Mushroom Industry and School of Biological Science and Biotechnology , Minnan Normal University , 36 Xianqianzhi Street , Zhangzhou 363000 , Fujian , People's Republic of China
| | - Dan Li
- College of Food and Biological Engineering , Jimei University , 43 Yindou Road , Xiamen 361021 , Fujian , People's Republic of China
- Key Laboratory of Agro-products Processing Technology at Jilin Provincial Universities , Changchun University , 6543 Weixing Road , Changchun 130022 , Jilin , People's Republic of China
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