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Bianchi G, Pessina A, Ami D, Signorelli S, de Divitiis M, Natalello A, Lotti M, Brambilla L, Brocca S, Mangiagalli M. Sustainable production of a biotechnologically relevant β-galactosidase in Escherichia coli cells using crude glycerol and cheese whey permeate. BIORESOURCE TECHNOLOGY 2024; 406:131063. [PMID: 38964512 DOI: 10.1016/j.biortech.2024.131063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/06/2024]
Abstract
Responsible use of natural resources and waste reduction are key concepts in bioeconomy. This study demonstrates that agro-food derived-biomasses from the Italian food industry, such as crude glycerol and cheese whey permeate (CWP), can be combined in a high-density fed-batch culture to produce a recombinant β-galactosidase from Marinomonas sp. ef1 (M-βGal). In a small-scale process (1.5 L) using 250 mL of crude glycerol and 300 mL of lactose-rich CWP, approximately 2000 kU of recombinant M-βGal were successfully produced along with 30 g of galactose accumulated in the culture medium. The purified M-βGal exhibited high hydrolysis efficiency in lactose-rich matrices, with hydrolysis yields of 82 % in skimmed milk at 4 °C and 94 % in CWP at 50 °C, highlighting its biotechnological potential. This approach demonstrates the effective use of crude glycerol and CWP in sustainable and cost-effective high-density Escherichia coli cultures, potentially applicable to recombinant production of various proteins.
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Affiliation(s)
- Greta Bianchi
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Alex Pessina
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Diletta Ami
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Samuele Signorelli
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Marcella de Divitiis
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Marina Lotti
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Luca Brambilla
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy.
| | - Marco Mangiagalli
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, Milano 20126, Italy.
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2
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Cui J, Wang Y, Zhou A, He S, Mao Z, Cao T, Wang N, Yuan Y. Cloning, Expression, Purification, and Characterization of a Novel β-Galactosidase/α-L-Arabinopyranosidase from Paenibacillus polymyxa KF-1. Molecules 2023; 28:7464. [PMID: 38005185 PMCID: PMC10673005 DOI: 10.3390/molecules28227464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Glycosidases are essential for the industrial production of functional oligosaccharides and many biotech applications. A novel β-galactosidase/α-L-arabinopyranosidase (PpBGal42A) of the glycoside hydrolase family 42 (GH42) from Paenibacillus polymyxa KF-1 was identified and functionally characterized. Using pNPG as a substrate, the recombinant PpBGal42A (77.16 kD) was shown to have an optimal temperature and pH of 30 °C and 6.0. Using pNPαArap as a substrate, the optimal temperature and pH were 40 °C and 7.0. PpBGal42A has good temperature and pH stability. Furthermore, Na+, K+, Li+, and Ca2+ (5 mmol/L) enhanced the enzymatic activity, whereas Mn2+, Cu2+, Zn2+, and Hg2+ significantly reduced the enzymatic activity. PpBGal42A hydrolyzed pNP-β-D-galactoside and pNP-α-L-arabinopyranoside. PpBGal42A liberated galactose from β-1,3/4/6-galactobiose and galactan. PpBGal42A hydrolyzed arabinopyranose at C20 of ginsenoside Rb2, but could not cleave arabinofuranose at C20 of ginsenoside Rc. Meanwhile, the molecular docking results revealed that PpBGal42A efficiently recognized and catalyzed lactose. PpBGal42A hydrolyzes lactose to galactose and glucose. PpBGal42A exhibits significant degradative activity towards citrus pectin when combined with pectinase. Our findings suggest that PpBGal42A is a novel bifunctional enzyme that is active as a β-galactosidase and α-L-arabinopyranosidase. This study expands on the diversity of bifunctional enzymes and provides a potentially effective tool for the food industry.
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Affiliation(s)
- Jing Cui
- Institute of Innovation Science & Technology, Central Laboratory, Changchun Normal University, Changchun 130031, China;
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Yibing Wang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Andong Zhou
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Shuhui He
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Zihan Mao
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Ting Cao
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Nan Wang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
| | - Ye Yuan
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China; (Y.W.); (A.Z.); (S.H.); (Z.M.); (N.W.)
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3
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Qiao K, Lv J, Chen L, Wang Y, Ma L, Wang J, Wang Z, Wang L, Ma Q, Fan S. GhSTP18, a member of sugar transport proteins family, negatively regulates salt stress in cotton. PHYSIOLOGIA PLANTARUM 2023; 175:e13982. [PMID: 37616007 DOI: 10.1111/ppl.13982] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/05/2023] [Accepted: 07/19/2023] [Indexed: 08/25/2023]
Abstract
The sugar transporter protein (STP) family has been shown to play important roles in plant growth, development, and stress response. However, it has not been studied in cotton compared to other major crops. In this study, we identified 90 STP genes from four cotton species, performed bioinformatic analysis, and focused on the role of GhSTP18 in salt stress. According to our results, cotton STP proteins were divided into four subgroups according to the phylogenetic tree. A synteny analysis suggested that whole-genome duplication (WGD) and segmental duplication were key drivers in the expansion of the STP gene family. The transcriptomic data analysis showed that 29 GhSTP genes exhibited sink-specific expression. Quantitative real time-polymerase chain reaction (qRT-PCR) analyses revealed that expression of GhSTP18 was induced by salt treatment, heat treatment, cold treatment, and drought treatment, and continuously increased during a salt stress time course. Notably, GhSTP18 encodes a plasma membrane-localized galactose transporter. Suppression of GhSTP18 transcription by a virus-induced gene silencing (VIGS) assay reduced sensitivity to salt stress in cotton, indicating that GhSTP18 negatively regulates plant salt tolerance. These results provide an important reference and resource for further studying and deploying STP genes for cotton improvement.
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Affiliation(s)
- Kaikai Qiao
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, China
| | - Jiaoyan Lv
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Lingling Chen
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Yanwen Wang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Lina Ma
- Hebei Agricultural University, Hebei Base of National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Baoding, Hebei, China
| | - Jin Wang
- Hebei Agricultural University, Hebei Base of National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Baoding, Hebei, China
| | - Zhe Wang
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Long Wang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Qifeng Ma
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, China
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shuli Fan
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
- National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, China
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China
- Hainan Yazhou Bay Seed Lab, Sanya, Hainan, China
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4
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Jo E, Kim J, Lee A, Moon K, Cha J. Identification and Characterization of a Novel Thermostable GDSL-Type Lipase from Geobacillus thermocatenulatus. J Microbiol Biotechnol 2021; 31:483-491. [PMID: 33622993 PMCID: PMC9706006 DOI: 10.4014/jmb.2012.12036] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/21/2021] [Accepted: 02/10/2021] [Indexed: 12/15/2022]
Abstract
Two putative genes, lip29 and est29, encoding lipolytic enzymes from the thermophilic bacterium Geobacillus thermocatenulatus KCTC 3921 were cloned and overexpressed in Escherichia coli. The recombinant Lip29 and Est29 were purified 67.3-fold to homogeneity with specific activity of 2.27 U/mg and recovery of 5.8% and 14.4-fold with specific activity of 0.92 U/mg and recovery of 1.3%, respectively. The molecular mass of each purified enzyme was estimated to be 29 kDa by SDSPAGE. The alignment analysis of amino acid sequences revealed that both enzymes belonged to GDSL lipase/esterase family including conserved blocks with SGNH catalytic residues which was mainly identified in plants before. While Est29 showed high specificity toward short-chain fatty acids (C4-C8), Lip29 showed strong lipolytic activity to long-chain fatty acids (C12-C16). The optimal activity of Lip29 toward p-nitrophenyl palmitate as a substrate was observed at 50°C and pH 9.5, respectively, and its activity was maintained more than 24 h at optimal temperatures, indicating that Lip29 was thermostable. Lip29 exhibited high tolerance against detergents and metal ions. The homology modeling and substrate docking revealed that the long-chain substrates showed the greatest binding affinity toward enzyme. Based on the biochemical and in silico analyses, we present for the first time a GDSL-type lipase in the thermophilic bacteria group.
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Affiliation(s)
- Eunhye Jo
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Jihye Kim
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Areum Lee
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Keumok Moon
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Jaeho Cha
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea,Microbiological Resource Research Institute, Pusan National University, Busan 46241, Republic of Korea,Corresponding author Phone: +82-51-510-2196 Fax: +82-51-514-1778 E-mail:
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5
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Ye M, Yu J, Shi X, Zhu J, Gao X, Liu W. Polysaccharides catabolism by the human gut bacterium - Bacteroides thetaiotaomicron: advances and perspectives. Crit Rev Food Sci Nutr 2020; 61:3569-3588. [PMID: 32779480 DOI: 10.1080/10408398.2020.1803198] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In recent years, the degradation processes of polysaccharides by human gut microbiota are receiving considerable attention due to the discoveries of the powerful function of gut microbiota. Gut microbiota has developed a sensitive, accurate, and complex system for sensing, capturing, and degrading different polysaccharides. Among the gut microbiota, Bacteroides thetaiotaomicron, a representative species of Bacteroides, is considered as the best degrader of polysaccharides and a potential probiotic in pharmaceutical and food industries. Here, we summarize the degradation system of B. thetaiotaomicron and the degradation pathways of different polysaccharides by B. thetaiotaomicron. We also describe a technical route for investigating a specific polysaccharide degradation pathway by human gut bacteria. In addition, we also provide the future perspectives in the development of novel polysaccharides or oligosaccharides drugs, precision microbiology medicine, and personalized nutrition.
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Affiliation(s)
- Meng Ye
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, PR China
| | - Juping Yu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, PR China
| | - Xuexia Shi
- Department of Clinical Pharmacy, Qinghai University Affiliated Hospital, Xining, PR China
| | - Jingyi Zhu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, PR China
| | - Xiangdong Gao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, PR China
| | - Wei Liu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, PR China.,Department of Clinical Pharmacy, Qinghai University Affiliated Hospital, Xining, PR China
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6
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Shulami S, Zehavi A, Belakhov V, Salama R, Lansky S, Baasov T, Shoham G, Shoham Y. Cross-utilization of β-galactosides and cellobiose in Geobacillus stearothermophilus. J Biol Chem 2020; 295:10766-10780. [PMID: 32493770 DOI: 10.1074/jbc.ra120.014029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/02/2020] [Indexed: 11/06/2022] Open
Abstract
Strains of the Gram-positive, thermophilic bacterium Geobacillus stearothermophilus possess elaborate systems for the utilization of hemicellulolytic polysaccharides, including xylan, arabinan, and galactan. These systems have been studied extensively in strains T-1 and T-6, representing microbial models for the utilization of soil polysaccharides, and many of their components have been characterized both biochemically and structurally. Here, we characterized routes by which G. stearothermophilus utilizes mono- and disaccharides such as galactose, cellobiose, lactose, and galactosyl-glycerol. The G. stearothermophilus genome encodes a phosphoenolpyruvate carbohydrate phosphotransferase system (PTS) for cellobiose. We found that the cellobiose-PTS system is induced by cellobiose and characterized the corresponding GH1 6-phospho-β-glucosidase, Cel1A. The bacterium also possesses two transport systems for galactose, a galactose-PTS system and an ABC galactose transporter. The ABC galactose transport system is regulated by a three-component sensing system. We observed that both systems, the sensor and the transporter, utilize galactose-binding proteins that also bind glucose with the same affinity. We hypothesize that this allows the cell to control the flux of galactose into the cell in the presence of glucose. Unexpectedly, we discovered that G. stearothermophilus T-1 can also utilize lactose and galactosyl-glycerol via the cellobiose-PTS system together with a bifunctional 6-phospho-β-gal/glucosidase, Gan1D. Growth curves of strain T-1 growing in the presence of cellobiose, with either lactose or galactosyl-glycerol, revealed initially logarithmic growth on cellobiose and then linear growth supported by the additional sugars. We conclude that Gan1D allows the cell to utilize residual galactose-containing disaccharides, taking advantage of the promiscuity of the cellobiose-PTS system.
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Affiliation(s)
- Smadar Shulami
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Arie Zehavi
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Valery Belakhov
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rachel Salama
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Timor Baasov
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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7
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Mangiagalli M, Lapi M, Maione S, Orlando M, Brocca S, Pesce A, Barbiroli A, Camilloni C, Pucciarelli S, Lotti M, Nardini M. The co-existence of cold activity and thermal stability in an Antarctic GH42 β-galactosidase relies on its hexameric quaternary arrangement. FEBS J 2020; 288:546-565. [PMID: 32363751 DOI: 10.1111/febs.15354] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/25/2020] [Accepted: 04/29/2020] [Indexed: 11/28/2022]
Abstract
To survive in cold environments, psychrophilic organisms produce enzymes endowed with high specific activity at low temperature. The structure of these enzymes is usually flexible and mostly thermolabile. In this work, we investigate the structural basis of cold adaptation of a GH42 β-galactosidase from the psychrophilic Marinomonas ef1. This enzyme couples cold activity with astonishing robustness for a psychrophilic protein, for it retains 23% of its highest activity at 5 °C and it is stable for several days at 37 °C and even 50 °C. Phylogenetic analyses indicate a close relationship with thermophilic β-galactosidases, suggesting that the present-day enzyme evolved from a thermostable scaffold modeled by environmental selective pressure. The crystallographic structure reveals the overall similarity with GH42 enzymes, along with a hexameric arrangement (dimer of trimers) not found in psychrophilic, mesophilic, and thermophilic homologues. In the quaternary structure, protomers form a large central cavity, whose accessibility to the substrate is promoted by the dynamic behavior of surface loops, even at low temperature. A peculiar cooperative behavior of the enzyme is likely related to the increase of the internal cavity permeability triggered by heating. Overall, our results highlight a novel strategy of enzyme cold adaptation, based on the oligomerization state of the enzyme, which effectively challenges the paradigm of cold activity coupled with intrinsic thermolability. DATABASE: Structural data are available in the Protein Data Bank database under the accession number 6Y2K.
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Affiliation(s)
- Marco Mangiagalli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy
| | - Michela Lapi
- Department of Biosciences, University of Milano, Italy
| | - Serena Maione
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy
| | - Marco Orlando
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy
| | | | - Alberto Barbiroli
- Department of Food, Environmental and Nutritional Sciences, University of Milano, Italy
| | | | - Sandra Pucciarelli
- School of Biosciences and Veterinary Medicine, University of Camerino, Italy
| | - Marina Lotti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy
| | - Marco Nardini
- Department of Biosciences, University of Milano, Italy
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8
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Dual Agarolytic Pathways in a Marine Bacterium, Vibrio sp. Strain EJY3: Molecular and Enzymatic Verification. Appl Environ Microbiol 2020; 86:AEM.02724-19. [PMID: 31924614 DOI: 10.1128/aem.02724-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 12/23/2019] [Indexed: 12/11/2022] Open
Abstract
Vibrio sp. strain EJY3 is an agarolytic marine bacterium that catabolizes 3,6-anhydro-l-galactose (AHG), a monomeric sugar unit of agarose. While the AHG catabolic pathway in EJY3 has been discovered recently, the complete agarolytic system of EJY3 remains unclear. We have identified five enzymes, namely, the β-agarases VejGH50A, VejGH50B, VejGH50C, and VejGH50D and the α-neoagarooligosaccharide (NAOS) hydrolase VejGH117, involved in the agarolytic system of EJY3. Based on the characterization of recombinant enzymes and intracellular metabolite analysis, we found that EJY3 catabolizes agarose via two different agarolytic pathways. Among the four β-agarases of EJY3, VejGH50A, VejGH50B, and VejGH50C were found to be extracellular agarases, producing mainly neoagarotetraose (NeoDP4) and neoagarobiose. By detecting intracellular NeoDP4 in EJY3 grown on agarose, NeoDP4 was observed being taken up by cells. Intriguingly, intracellular NeoDP4 acted as a branching point for the two different downstream agarolytic pathways. First, via the well-known agarolytic pathway, NeoDP4 was depolymerized into monomeric sugars by the exo-type β-agarase VejGH50D and the α-NAOS hydrolase VejGH117. Second, via the newly found alternative agarolytic pathway, NeoDP4 was depolymerized into AHG and agarotriose (AgaDP3) by VejGH117, and AgaDP3 then was completely depolymerized into monomeric sugars by sequential reactions of the agarolytic β-galactosidases (ABG) VejABG and VejGH117. Therefore, by experimentally verifying agarolytic enzymatic activity and transport of NeoDP4 into EJY3 cells, we revealed that EJY3 possesses both the known pathway and the newly discovered alternative pathway that involves α-NAOS hydrolase and ABG.IMPORTANCE Agarose is the main polysaccharide of red macroalgae and is composed of galactose and 3,6-anhydro-l-galactose. Many marine bacteria possess enzymes capable of depolymerizing agarose into oligomers and then depolymerizing the oligomers into monomers. Here, we experimentally verified that both a well-known agarolytic pathway and a novel agarolytic pathway exist in a marine bacterium, Vibrio sp. strain EJY3. In agarolytic pathways, agarose is depolymerized mainly into 4-sugar-unit oligomers by extracellular enzymes, which are then transported into cells. The imported oligomers are intracellularly depolymerized into galactose and 3,6-anhydro-l-galactose by two different agarolytic pathways, using different combinations of intracellular enzymes. These results elucidate the depolymerization routes of red macroalgal biomass in the ocean by marine bacteria and provide clues for developing industrial processes for efficiently producing sugars from red macroalgae.
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9
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Torpenholt S, Poulsen JCN, Muderspach SJ, De Maria L, Lo Leggio L. Structure of Aspergillus aculeatus β-1,4-galactanase in complex with galactobiose. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2019; 75:399-404. [PMID: 31204685 DOI: 10.1107/s2053230x19005612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/24/2019] [Indexed: 11/10/2022]
Abstract
β-1,4-Galactanases are glycoside hydrolases that are involved in the degradation of pectin and belong to family 53 in the classification of glycoside hydrolases. Previous studies have elucidated the structures of several fungal and two bacterial galactanases, while biochemical studies have indicated differences in the product profiles of different members of the family. Structural studies of ligand complexes have to date been limited to the bacterial members of the family. Here, the first structure of a fungal galactanase in complex with a disaccharide is presented. Galactobiose binds to subsites -1 and -2, thus improving our understanding of ligand binding to galactanases.
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Affiliation(s)
- Søs Torpenholt
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Jens Christian N Poulsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | | | | | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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10
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González-Ayón MA, Licea-Claveríe Á, Valdez-Torres JB, Picos-Corrales LA, Vélez-de la Rocha R, Contreras-Esquivel JC, Labavitch JM, Sañudo-Barajas JA. Enzyme-Catalyzed Production of Potato Galactan-Oligosaccharides and Its Optimization by Response Surface Methodology. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E1465. [PMID: 31067636 PMCID: PMC6539101 DOI: 10.3390/ma12091465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 11/30/2022]
Abstract
This work shows an optimized enzymatic hydrolysis of high molecular weight potato galactan yielding pectic galactan-oligosaccharides (PGOs), where endo-β-1,4-galactanase (galactanase) from Cellvibrio japonicus and Clostridium thermocellum was used. For this, response surface methodology (RSM) by central composite design (CCD) was applied. The parameters varied were temperature (°C), pH, incubation time (min), and enzyme/substrate ratio (U/mg). The optimized conditions for the production of low degree of polymerization (DP) PGOs were obtained for each enzyme by spectrophotometric assay and confirmed by chromatography. The optimal conditions predicted for the use of C. japonicus galactanase to obtain PGOs of DP = 2 were T = 51.8 °C, pH 5, E/S = 0.508 U/mg, and t = 77.5 min. For DP = 3, they were T = 21 °C, pH 9, E/S = 0.484 U/mg, and t = 12.5 min; and for DP = 4, they were T = 21 °C, pH 5, E/S = 0.462 U/mg, and t = 12.5 min. The efficiency results were 51.3% for substrate hydrolysis. C. thermocellum galactanase had a lower yield (35.7%) and optimized conditions predicted for PGOs of DP = 2 were T = 60 °C, pH 5, E/S = 0.525 U/mg, and time = 148 min; DP = 3 were T = 59.7 °C, pH 5, E/S = 0.506 U/mg, and time = 12.5 min; and DP = 4, were T = 34.5 °C, pH 11, E/S = 0.525 U/mg, and time = 222.5 min. Fourier transformed infrared (FT-IR) and nuclear magnetic resonance (NMR) characterizations of PGOs are presented.
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Affiliation(s)
| | - Ángel Licea-Claveríe
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/Instituto Tecnológico de Tijuana, Apartado Postal 1166, Tijuana, Baja California 22510, Mexico.
| | | | - Lorenzo A Picos-Corrales
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacán 80013, Sinaloa, Mexico.
| | | | | | - John M Labavitch
- Plant Sciences Department, University of California, Davis, CA 95616, USA.
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11
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Wu P, Guo Y, Golly MK, Ma H, He R, Luo S, Zhang C, Zhang L, Zhu J. Feasibility study on direct fermentation of soybean meal by Bacillus stearothermophilus under non-sterile conditions. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2019; 99:3291-3298. [PMID: 30552769 DOI: 10.1002/jsfa.9542] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/22/2018] [Accepted: 12/12/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND To evaluate the feasibility of high-temperature solid-state fermentation (SSF) using soybean meal (SBM) during the non-sterile process, Bacillus stearothermophilus was employed to assess the nutritional quality and bioactivity of SBM after fermentation. RESULTS The fermented SBM (FSBM) without autoclaving showed significant improvements in nutritional quality and bioactivity. The contents of peptides and crude and soluble proteins increased by 131.21%, 5.3% and 15.52%, respectively. Meanwhile, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging ability, reducing ability and hydroxyl free radical-scavenging activity rose by 57.07%, 238.92% and 368.26%, respectively. The inhibitory activity of angiotensin I-converting enzyme increased from 1.43 ± 0.83% to 26.89 ± 1.03%, while the trypsin inhibitor activity decreased by 74.05%. The contents of neutral and alkaline proteases and the growth of microorganisms in FSBM without autoclaving were higher and better than in steam-treated FSBM. After steam treatment, the water-holding capacity of SBM decreased, and a high crosslink density was observed on the surface of SBM particles. CONCLUSIONS It is feasible to ferment SBM by high-temperature SSF using B. stearothermophilus under non-sterile conditions. Adverse effects of SSF using sterile SBM might be owing to the low water-holding capacity caused by autoclaving. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Ping Wu
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Yiting Guo
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Moses Kwaku Golly
- Faculty of Applied Sciences and Technology, Sunyani Technical University, Sunyani, Ghana
| | - Haile Ma
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang, China
- Physical Processing of Agricultural Products Key Lab of Jiangsu Province, Zhenjiang, China
| | - Ronghai He
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Shilong Luo
- Grain and Oil Quality Inspection Center, Sinograin (Zhenjiang) Grain and Oil Co., Ltd, Zhenjiang, China
| | - Cheng Zhang
- Grain and Oil Quality Inspection Center, Sinograin (Zhenjiang) Grain and Oil Co., Ltd, Zhenjiang, China
| | - Liuping Zhang
- Grain and Oil Quality Inspection Center, Sinograin (Zhenjiang) Grain and Oil Co., Ltd, Zhenjiang, China
| | - Jinhua Zhu
- School of Food & Biological Engineering, Jiangsu University, Zhenjiang, China
- Changzhou Sanhuan Biological Complete Equipment Co., Ltd, Changzhou, China
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12
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Lebre PH, Aliyu H, De Maayer P, Cowan DA. In silico characterization of the global Geobacillus and Parageobacillus secretome. Microb Cell Fact 2018; 17:156. [PMID: 30285747 PMCID: PMC6171300 DOI: 10.1186/s12934-018-1005-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 09/26/2018] [Indexed: 11/17/2022] Open
Abstract
Background Geobacillus and Parageobacillus are two ecologically diverse thermophilic genera within the phylum Firmicutes. These taxa have long been of biotechnological interest due to their ability to secrete thermostable enzymes and other biomolecules that have direct applications in various industrial and clinical fields. Despite the commercial and industrial interest in these microorganisms, the full scope of the secreted protein, i.e. the secretome, of Geobacillus and Parageobacillus species remains largely unexplored, with most studies focusing on single enzymes. A genome-wide exploration of the global secretome can provide a platform for understanding the extracellular functional “protein cloud” and the roles that secreted proteins play in the survival and adaptation of these biotechnologically relevant organisms. Results In the present study, the global secretion profile of 64 Geobacillus and Parageobacillus strains, comprising 772 distinct proteins, was predicted using comparative genomic approaches. Thirty-one of these proteins are shared across all strains used in this study and function in cell-wall/membrane biogenesis as well as transport and metabolism of carbohydrates, amino acids and inorganic ions. An analysis of the clustering patterns of the secretomes of the 64 strains according to shared functional orthology revealed a correlation between the secreted profiles of different strains and their phylogeny, with Geobacillus and Parageobacillus species forming two distinct functional clades. Conclusions The in silico characterization of the global secretome revealed a metabolically diverse set of secreted proteins, which include proteases, glycoside hydrolases, nutrient binding proteins and toxins. Electronic supplementary material The online version of this article (10.1186/s12934-018-1005-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Habibu Aliyu
- Technical Biology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Pieter De Maayer
- School of Molecular and Cell Biology, University of Witwatersrand, Johannesburg, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
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13
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Viborg AH, Katayama T, Arakawa T, Abou Hachem M, Lo Leggio L, Kitaoka M, Svensson B, Fushinobu S. Discovery of α-l-arabinopyranosidases from human gut microbiome expands the diversity within glycoside hydrolase family 42. J Biol Chem 2017; 292:21092-21101. [PMID: 29061847 DOI: 10.1074/jbc.m117.792598] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/18/2017] [Indexed: 12/30/2022] Open
Abstract
Enzymes of the glycoside hydrolase family 42 (GH42) are widespread in bacteria of the human gut microbiome and play fundamental roles in the decomposition of both milk and plant oligosaccharides. All GH42 enzymes characterized so far have β-galactosidase activity. Here, we report the existence of a GH42 subfamily that is exclusively specific for α-l-arabinopyranoside and describe the first representative of this subfamily. We found that this enzyme (BlArap42B) from a probiotic Bifidobacterium species cannot hydrolyze β-galactosides. However, BlArap42B effectively hydrolyzed paeonolide and ginsenoside Rb2, plant glycosides containing an aromatic aglycone conjugated to α-l-arabinopyranosyl-(1,6)-β-d-glucopyranoside. Paeonolide, a natural glycoside from the roots of the plant genus Paeonia, is not hydrolyzed by classical GH42 β-galactosidases. X-ray crystallography revealed a unique Trp345-X12-Trp358 sequence motif at the BlArap42B active site, as compared with a Phe-X12-His motif in classical GH42 β-galactosidases. This analysis also indicated that the C6 position of galactose is blocked by the aromatic side chains, hence allowing accommodation only of Arap lacking this carbon. Automated docking of paeonolide revealed that it can fit into the BlArap42B active site. The Glcp moiety of paeonolide stacks onto the aromatic ring of the Trp252 at subsite +1 and C4-OH is hydrogen bonded with Asp249 Moreover, the aglycone stacks against Phe421 from the neighboring monomer in the BlArap42B trimer, forming a proposed subsite +2. These results further support the notion that evolution of metabolic specialization can be tracked at the structural level in key enzymes facilitating degradation of specific glycans in an ecological niche.
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Affiliation(s)
- Alexander Holm Viborg
- From the Department of Biotechnology, The University of Tokyo, Tokyo 113-8657, Japan.,the Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2400 Kgs. Lyngby, Denmark
| | - Takane Katayama
- the Graduate School of Biostudies, Kyoto University, Koyoto 606-8502, Japan.,the Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, Ishikawa 921-8836, Japan
| | - Takatoshi Arakawa
- From the Department of Biotechnology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Maher Abou Hachem
- the Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2400 Kgs. Lyngby, Denmark
| | - Leila Lo Leggio
- the Department of Chemistry, University of Copenhagen, Copenhagen 2100, Denmark, and
| | - Motomitsu Kitaoka
- the Food Research Institute, National Agriculture and Food Research Organization, Tsukuba 305-8642, Japan
| | - Birte Svensson
- the Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2400 Kgs. Lyngby, Denmark
| | - Shinya Fushinobu
- From the Department of Biotechnology, The University of Tokyo, Tokyo 113-8657, Japan,
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14
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Lansky S, Zehavi A, Belrhali H, Shoham Y, Shoham G. Structural basis for enzyme bifunctionality – the case of Gan1D fromGeobacillus stearothermophilus. FEBS J 2017; 284:3931-3953. [DOI: 10.1111/febs.14283] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/31/2017] [Accepted: 09/28/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Shifra Lansky
- Institute of Chemistry The Laboratory for Structural Chemistry and Biology The Hebrew University of Jerusalem Israel
| | - Arie Zehavi
- Department of Biotechnology and Food Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | | | - Yuval Shoham
- Department of Biotechnology and Food Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | - Gil Shoham
- Institute of Chemistry The Laboratory for Structural Chemistry and Biology The Hebrew University of Jerusalem Israel
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15
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Habib C, Yu Y, Gozzi K, Ching C, Shemesh M, Chai Y. Characterization of the regulation of a plant polysaccharide utilization operon and its role in biofilm formation in Bacillus subtilis. PLoS One 2017; 12:e0179761. [PMID: 28617843 PMCID: PMC5472308 DOI: 10.1371/journal.pone.0179761] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/02/2017] [Indexed: 11/18/2022] Open
Abstract
The soil bacterium Bacillus subtilis is often found in association with plants in the rhizosphere. Previously, plant polysaccharides have been shown to stimulate formation of root-associated multicellular communities, or biofilms, in this bacterium, yet the underlying mechanism is not fully understood. A five-gene gan operon (ganSPQAB) in B. subtilis has recently been shown to be involved in utilization of the plant-derived polysaccharide galactan. Despite these findings, molecular details about the regulation of the operon and the role of the operon in biofilm formation remain elusive. In this study, we performed comprehensive genetic analyses on the regulation of the gan operon. We show that this operon is regulated both by a LacI-like transcription repressor (GanR), which directly binds to pairs of inverted DNA repeats in the promoter region of the operon, and by the catabolite control protein A (CcpA). Derepression can be triggered by the presence of the inducer β-1,4-galactobiose, a hydrolysis product of galactan, or in situ when B. subtilis cells are associated with plant roots. In addition to the transcriptional regulation, the encoded ß-galactosidase GanA (by ganA), which hydrolyzes ß-1,4-galactobiose into galactose, is inhibited at the enzymatic level by the catalytic product galactose. Thus, the galactan utilization pathway is under complex regulation involving both positive and negative feedback mechanisms in B. subtilis. We discuss about the biological significance of such complex regulation as well as a hypothesis of biofilm induction by galactan via multiple mechanisms.
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Affiliation(s)
- Cameron Habib
- Department of Biology, Northeastern University, Boston, MA, United States of America
| | - Yiyang Yu
- Department of Biology, Northeastern University, Boston, MA, United States of America
| | - Kevin Gozzi
- Department of Biology, Northeastern University, Boston, MA, United States of America
| | - Carly Ching
- Department of Biology, Northeastern University, Boston, MA, United States of America
| | - Moshe Shemesh
- Agricultural Research Organization The Volcani Center, Rishon LeZion, Israel
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA, United States of America
- * E-mail:
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16
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Role of the ganSPQAB Operon in Degradation of Galactan by Bacillus subtilis. J Bacteriol 2016; 198:2887-96. [PMID: 27501980 DOI: 10.1128/jb.00468-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 07/29/2016] [Indexed: 11/20/2022] Open
Abstract
Bacillus subtilis possesses different enzymes for the utilization of plant cell wall polysaccharides. This includes a gene cluster containing galactan degradation genes (ganA and ganB), two transporter component genes (ganQ and ganP), and the sugar-binding lipoprotein-encoding gene ganS (previously known as cycB). These genes form an operon that is regulated by GanR. The degradation of galactan by B. subtilis begins with the activity of extracellular GanB. GanB is an endo-β-1,4-galactanase and is a member of glycoside hydrolase (GH) family 53. This enzyme was active on high-molecular-weight arabinose-free galactan and mainly produced galactotetraose as well as galactotriose and galactobiose. These galacto-oligosaccharides may enter the cell via the GanQP transmembrane proteins of the galactan ABC transporter. The specificity of the galactan ABC transporter depends on the sugar-binding lipoprotein, GanS. Purified GanS was shown to bind galactotetraose and galactotriose using thermal shift assay. The energy for this transport is provided by MsmX, an ATP-binding protein. The transported galacto-oligosaccharides are further degraded by GanA. GanA is a β-galactosidase that belongs to GH family 42. The GanA enzyme was able to hydrolyze short-chain β-1,4-galacto-oligosaccharides as well as synthetic β-galactopyranosides into galactose. Thermal shift assay as well as electrophoretic mobility shift assay demonstrated that galactobiose is the inducer of the galactan operon regulated by GanR. DNase I footprinting revealed that the GanR protein binds to an operator overlapping the -35 box of the σ(A)-type promoter of Pgan, which is located upstream of ganS IMPORTANCE: Bacillus subtilis is a Gram-positive soil bacterium that utilizes different types of carbohydrates, such as pectin, as carbon sources. So far, most of the pectin degradation systems and enzymes have been thoroughly studied in B. subtilis Nevertheless, the B. subtilis utilization system of galactan, which is found as the side chain of the rhamnogalacturonan type I complex in pectin, has remained partially studied. Here, we investigated the galactan utilization system consisting of the ganSPQAB operon and its regulator ganR This study improves our knowledge of the carbohydrate degradation systems of B. subtilis, especially the pectin degradation systems. Moreover, the galactan-degrading enzymes may be exploited for the production of galacto-oligosaccharides, which are used as prebiotic substances in the food industry.
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17
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Torpenholt S, De Maria L, Olsson MHM, Christensen LH, Skjøt M, Westh P, Jensen JH, Lo Leggio L. Effect of mutations on the thermostability of Aspergillus aculeatus β-1,4-galactanase. Comput Struct Biotechnol J 2015; 13:256-64. [PMID: 25941560 PMCID: PMC4412966 DOI: 10.1016/j.csbj.2015.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/27/2015] [Accepted: 03/31/2015] [Indexed: 11/17/2022] Open
Abstract
New variants of β-1,4-galactanase from the mesophilic organism Aspergillus aculeatus were designed using the structure of β-1,4-galactanase from the thermophile organism Myceliophthora thermophila as a template. Some of the variants were generated using PROPKA 3.0, a validated pKa prediction tool, to test its usefulness as an enzyme design tool. The PROPKA designed variants were D182N and S185D/Q188T, G104D/A156R. Variants Y295F and G306A were designed by a consensus approach, as a complementary and validated design method. D58N was a stabilizing mutation predicted by both methods. The predictions were experimentally validated by measurements of the melting temperature (Tm ) by differential scanning calorimetry. We found that the Tm is elevated by 1.1 °C for G306A, slightly increased (in the range of 0.34 to 0.65 °C) for D182N, D58N, Y295F and unchanged or decreased for S185D/Q188T and G104D/A156R. The Tm changes were in the range predicted by PROPKA. Given the experimental errors, only the D58N and G306A show significant increase in thermodynamic stability. Given the practical importance of kinetic stability, the kinetics of the irreversible enzyme inactivation process were also investigated for the wild-type and three variants and found to be biphasic. The half-lives of thermal inactivation were approximately doubled in G306A, unchanged for D182N and, disappointingly, a lot lower for D58N. In conclusion, this study tests a new method for estimating Tm changes for mutants, adds to the available data on the effect of substitutions on protein thermostability and identifies an interesting thermostabilizing mutation, which may be beneficial also in other galactanases.
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Key Words
- AZCL-galactan, azurine-crosslinked galactan
- AaGal, β-1,4-galactanase from Aspergillus aculeatus
- CAZY, carbohydrate active enzyme database
- Computational prediction
- DSC, differential scanning calorimetry
- GH53
- MtGal, β-1,4-galactanase from Myceliophthora thermophila
- Protein design
- Thermostability
- Tm, melting temperature
- TsGal, Talaromyces stipitatus galactanase
- WT, wild type
- β-1,4-galactanase
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Affiliation(s)
- Søs Torpenholt
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | | | - Mats H M Olsson
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | | | - Michael Skjøt
- Novozymes A/S, Smørmosevej 25, 2880 Bagsværd, Denmark
| | - Peter Westh
- NSM, Research Unit for Functional Biomaterials, University of Roskilde, Universitetsvej 1, 4000 Roskilde, Denmark
| | - Jan H Jensen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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18
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Dann R, Lansky S, Lavid N, Zehavi A, Belakhov V, Baasov T, Dvir H, Manjasetty B, Belrhali H, Shoham Y, Shoham G. Preliminary crystallographic analysis of Xyn52B2, a GH52 β-D-xylosidase from Geobacillus stearothermophilus T6. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2014; 70:1675-82. [PMID: 25484225 DOI: 10.1107/s2053230x14023887] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/29/2014] [Indexed: 11/10/2022]
Abstract
Geobacillus stearothermophilus T6 is a thermophilic bacterium that possesses an extensive hemicellulolytic system, including over 40 specific genes that are dedicated to this purpose. For the utilization of xylan, the bacterium uses an extracellular xylanase which degrades xylan to decorated xylo-oligomers that are imported into the cell. These oligomers are hydrolyzed by side-chain-cleaving enzymes such as arabinofuranosidases, acetylesterases and a glucuronidase, and finally by an intracellular xylanase and a number of β-xylosidases. One of these β-xylosidases is Xyn52B2, a GH52 enzyme that has already proved to be useful for various glycosynthesis applications. In addition to its demonstrated glycosynthase properties, interest in the structural aspects of Xyn52B2 stems from its special glycoside hydrolase family, GH52, the structures and mechanisms of which are only starting to be resolved. Here, the cloning, overexpression, purification and crystallization of Xyn52B2 are reported. The most suitable crystal form that has been obtained belonged to the orthorhombic P212121 space group, with average unit-cell parameters a = 97.7, b = 119.1, c = 242.3 Å. Several X-ray diffraction data sets have been collected from flash-cooled crystals of this form, including the wild-type enzyme (3.70 Å resolution), the E335G catalytic mutant (2.95 Å resolution), a potential mercury derivative (2.15 Å resolution) and a selenomethionine derivative (3.90 Å resolution). These data are currently being used for detailed three-dimensional structure determination of the Xyn52B2 protein.
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Affiliation(s)
- Roie Dann
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Noa Lavid
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Arie Zehavi
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Valery Belakhov
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Timor Baasov
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Hay Dvir
- Technion Center for Structural Biology, Lorry I. Lokey Center for Life Sciences and Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Babu Manjasetty
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Hassan Belrhali
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Affiliation(s)
- David J Studholme
- Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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20
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Lansky S, Salama R, Dann R, Shner I, Manjasetty BA, Belrhali H, Shoham Y, Shoham G. Cloning, purification and preliminary crystallographic analysis of Ara127N, a GH127 β-L-arabinofuranosidase from Geobacillus stearothermophilus T6. Acta Crystallogr F Struct Biol Commun 2014; 70:1038-45. [PMID: 25084377 PMCID: PMC4118799 DOI: 10.1107/s2053230x14012680] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 05/31/2014] [Indexed: 12/27/2022] Open
Abstract
The L-arabinan utilization system of Geobacillus stearothermophilus T6 is composed of five transcriptional units that are clustered within a 38 kb DNA segment. One of the transcriptional units contains 11 genes, the last gene of which (araN) encodes a protein, Ara127N, that belongs to the newly established GH127 family. Ara127N shares 44% sequence identity with the recently characterized HypBA1 protein from Bifidobacterium longum and thus is likely to function similarly as a β-L-arabinofuranosidase. β-L-Arabinofuranosidases are enzymes that hydrolyze β-L-arabinofuranoside linkages, the less common form of such linkages, a unique enzymatic activity that has been identified only recently. The interest in the structure and mode of action of Ara127N therefore stems from its special catalytic activity as well as its membership of the new GH127 family, the structure and mechanism of which are only starting to be resolved. Ara127N has recently been cloned, overexpressed, purified and crystallized. Two suitable crystal forms have been obtained: one (CTP form) belongs to the monoclinic space group P21, with unit-cell parameters a = 104.0, b = 131.2, c = 107.6 Å, β = 112.0°, and the other (RB form) belongs to the orthorhombic space group P212121, with unit-cell parameters a = 65.5, b = 118.1, c = 175.0 Å. A complete X-ray diffraction data set has been collected to 2.3 Å resolution from flash-cooled crystals of the wild-type enzyme (RB form) at -173°C using synchrotron radiation. A selenomethionine derivative of Ara127N has also been prepared and crystallized for multi-wavelength anomalous diffraction (MAD) experiments. Crystals of selenomethionine Ara127N appeared to be isomorphous to those of the wild type (CTP form) and enabled the measurement of a three-wavelength MAD diffraction data set at the selenium absorption edge. These data are currently being used for detailed three-dimensional structure determination of the Ara127N protein.
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Affiliation(s)
- Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Rachel Salama
- Department of Biotechnology and Food Engineering, Technion–Israel Institute of Technology, Haifa 32000, Israel
| | - Roie Dann
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Izhak Shner
- Department of Biotechnology and Food Engineering, Technion–Israel Institute of Technology, Haifa 32000, Israel
| | - Babu A. Manjasetty
- European Molecular Biology Laboratory, Grenoble Outstation, 38000 Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes–EMBL–CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Hassan Belrhali
- European Molecular Biology Laboratory, Grenoble Outstation, 38000 Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes–EMBL–CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion–Israel Institute of Technology, Haifa 32000, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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21
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Shulami S, Shenker O, Langut Y, Lavid N, Gat O, Zaide G, Zehavi A, Sonenshein AL, Shoham Y. Multiple regulatory mechanisms control the expression of the Geobacillus stearothermophilus gene for extracellular xylanase. J Biol Chem 2014; 289:25957-75. [PMID: 25070894 DOI: 10.1074/jbc.m114.592873] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Geobacillus stearothermophilus T-6 produces a single extracellular xylanase (Xyn10A) capable of producing short, decorated xylo-oligosaccharides from the naturally branched polysaccharide, xylan. Gel retardation assays indicated that the master negative regulator, XylR, binds specifically to xylR operators in the promoters of xylose and xylan-utilization genes. This binding is efficiently prevented in vitro by xylose, the most likely molecular inducer. Expression of the extracellular xylanase is repressed in medium containing either glucose or casamino acids, suggesting that carbon catabolite repression plays a role in regulating xynA. The global transcriptional regulator CodY was shown to bind specifically to the xynA promoter region in vitro, suggesting that CodY is a repressor of xynA. The xynA gene is located next to an uncharacterized gene, xynX, that has similarity to the NIF3 (Ngg1p interacting factor 3)-like protein family. XynX binds specifically to a 72-bp fragment in the promoter region of xynA, and the expression of xynA in a xynX null mutant appeared to be higher, indicating that XynX regulates xynA. The specific activity of the extracellular xylanase increases over 50-fold during early exponential growth, suggesting cell density regulation (quorum sensing). Addition of conditioned medium to fresh and low cell density cultures resulted in high expression of xynA, indicating that a diffusible extracellular xynA density factor is present in the medium. The xynA density factor is heat-stable, sensitive to proteases, and was partially purified using reverse phase liquid chromatography. Taken together, these results suggest that xynA is regulated by quorum-sensing at low cell densities.
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Affiliation(s)
- Smadar Shulami
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Ofer Shenker
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Yael Langut
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Noa Lavid
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Orit Gat
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Galia Zaide
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Arie Zehavi
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
| | - Abraham L Sonenshein
- the Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Yuval Shoham
- From the Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel and
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22
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Lansky S, Alalouf O, Salama R, Dvir H, Shoham Y, Shoham G. Preliminary crystallographic analysis of a double mutant of the acetyl xylo-oligosaccharide esterase Axe2 in its dimeric form. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2014; 70:476-81. [PMID: 24699743 DOI: 10.1107/s2053230x14004129] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 02/22/2014] [Indexed: 11/11/2022]
Abstract
Xylans are polymeric sugars constituting a significant part of the plant cell wall. They are usually substituted with acetyl side groups attached at positions 2 or 3 of the xylose backbone units. Acetylxylan esterases are part of the hemicellulolytic system of many microorganisms which utilize plant biomass for growth. These enzymes hydrolyze the ester linkages of the xylan acetyl groups and thus improve the accessibility of main-chain-hydrolyzing enzymes and their ability to break down the sugar backbone units. The acetylxylan esterases are therefore critically important for those microorganisms and as such could be used for a wide range of biotechnological applications. The structure of an acetylxylan esterase (Axe2) isolated from the thermophilic bacterium Geobacillus stearothermophilus T6 has been determined, and it has been demonstrated that the wild-type enzyme is present as a unique torus-shaped octamer in the crystal and in solution. In order to understand the functional origin of this unique oligomeric structure, a series of rational noncatalytic, site-specific mutations have been made on Axe2. Some of these mutations led to a different dimeric form of the protein, which showed a significant reduction in catalytic activity. One of these double mutants, Axe2-Y184F-W190P, has recently been overexpressed, purified and crystallized. The best crystals obtained belonged to the orthorhombic space group P212121, with unit-cell parameters a = 71.1, b = 106.0, c = 378.6 Å. A full diffraction data set to 2.3 Å resolution has been collected from a flash-cooled crystal of this type at 100 K using synchrotron radiation. This data set is currently being used for the three-dimensional structure analysis of the Axe2-Y184F-W190P mutant in its dimeric form.
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Affiliation(s)
- Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Onit Alalouf
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Rachel Salama
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Hay Dvir
- Technion Center for Structural Biology, Lorry I. Lokey Center for Life Sciences and Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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23
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Lansky S, Zehavi A, Dann R, Dvir H, Belrhali H, Shoham Y, Shoham G. Purification, crystallization and preliminary crystallographic analysis of Gan1D, a GH1 6-phospho-β-galactosidase from Geobacillus stearothermophilus T1. Acta Crystallogr F Struct Biol Commun 2014; 70:225-31. [PMID: 24637762 PMCID: PMC3936444 DOI: 10.1107/s2053230x13034778] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 12/28/2013] [Indexed: 11/10/2022] Open
Abstract
Geobacillus stearothermophilus T1 is a Gram-positive thermophilic soil bacterium that contains an extensive system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. The bacterium uses a number of extracellular enzymes that break down the high-molecular-weight polysaccharides into short oligosaccharides, which enter the cell and are further hydrolyzed into sugar monomers by dedicated intracellular glycoside hydrolases. The interest in the biochemical characterization and structural analysis of these proteins originates mainly from the wide range of their potential biotechnological applications. Studying the different hemicellulolytic utilization systems in G. stearothermophilus T1, a new galactan-utilization gene cluster was recently identified, which encodes a number of proteins, one of which is a GH1 putative 6-phospho-β-galactosidase (Gan1D). Gan1D has recently been cloned, overexpressed, purified and crystallized as part of its comprehensive structure-function study. The best crystals obtained for this enzyme belonged to the triclinic space group P1, with average crystallographic unit-cell parameters of a = 67.0, b = 78.1, c = 92.1 Å, α = 102.4, β = 93.5, γ = 91.7°. A full diffraction data set to 1.33 Å resolution has been collected for the wild-type enzyme, as measured from flash-cooled crystals at 100 K, using synchrotron radiation. These data are currently being used for the detailed three-dimensional crystal structure analysis of Gan1D.
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Affiliation(s)
- Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Arie Zehavi
- Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Roie Dann
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Hay Dvir
- Technion Center for Structural Biology, The Lorry I. Lokey Interdisciplinary Center for Life Science and Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Hassan Belrhali
- European Molecular Biology Laboratory, Grenoble Outstation, and Unit for Virus–Host Cell Interactions, European Synchrotron Radiation Facility, Université Grenoble Alpes–EMBL–CNRS, 6 Rue Jules Horowitz, 38042 Grenoble, France
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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24
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Rodriguez AC, Kohler JJ. Recognition of diazirine-modified O-GlcNAc by human O-GlcNAcase. MEDCHEMCOMM 2014; 5:1227-1234. [PMID: 25068034 DOI: 10.1039/c4md00164h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The mammalian O-GlcNAc hydrolase (OGA) removes O-GlcNAc from serine and threonine residues on intracellular glycoproteins. OGA activity is sensitive to N-acyl substitutions to O-GlcNAc, with alkyl diazirine-modified O-GlcNAc (O-GlcNDAz) being completely resistant to removal by OGA. Using homology modeling, we identified OGA residues proximal to the N-acyl position of O-GlcNAc substrate. Mutation of one of these residues, C215, results in mutant enzymes that are able to hydrolytically remove O-GlcNDAz from a model compound. Further, the C215A mutant is capable of removing O-GlcNDAz from a peptide substrate. These results can be used to improve metabolism of O-GlcNAc analogs in cells. In addition, the enzyme specificity studies reported here provide new insight into the active site of OGA, an important drug target.
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Affiliation(s)
- Andrea C Rodriguez
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
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25
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Solomon HV, Tabachnikov O, Feinberg H, Govada L, Chayen NE, Shoham Y, Shoham G. Crystallization and preliminary crystallographic analysis of GanB, a GH42 intracellular β-galactosidase from Geobacillus stearothermophilus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1114-9. [PMID: 24100561 PMCID: PMC3792669 DOI: 10.1107/s1744309113023609] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 08/21/2013] [Indexed: 11/11/2022]
Abstract
Geobacillus stearothermophilus T-6 is a Gram-positive thermophilic soil bacterium that contains a multi-enzyme system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. The bacterium uses a number of endo-acting extracellular enzymes that break down the high-molecular-weight polysaccharides into decorated oligosaccharides. These oligosaccharides enter the cell and are further hydrolyzed into sugar monomers by a set of intracellular glycoside hydrolases. One of these intracellular degrading enzymes is GanB, a glycoside hydrolase family 42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides to galactose. GanB and related enzymes therefore play an important part in the hemicellulolytic utilization system of many microorganisms which use plant biomass for growth. The interest in the biochemical characterization and structural analysis of these enzymes stems from their potential biotechnological applications. GanB from G. stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized in our laboratory as part of its complete structure-function study. The best crystals obtained for this enzyme belong to the primitive orthorhombic space group P2₁2₁2₁, with average crystallographic unit-cell parameters of a=71.84, b=181.35, c=196.57 Å. Full diffraction data sets to 2.45 and 2.50 Å resolution have been collected for both the wild-type enzyme and its E323A nucleophile catalytic mutant, respectively, as measured from flash-cooled crystals at 100 K using synchrotron radiation. These data are currently being used for the full three-dimensional crystal structure determination of GanB.
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Affiliation(s)
- Hodaya V. Solomon
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Orly Tabachnikov
- Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Hadar Feinberg
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Lata Govada
- Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, England
| | - Naomi E. Chayen
- Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, England
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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26
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Polysaccharide-degrading thermophiles generated by heterologous gene expression in Geobacillus kaustophilus HTA426. Appl Environ Microbiol 2013; 79:5151-8. [PMID: 23793634 DOI: 10.1128/aem.01506-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Thermophiles have important advantages over mesophiles as host organisms for high-temperature bioprocesses, functional production of thermostable enzymes, and efficient expression of enzymatic activities in vivo. To capitalize on these advantages of thermophiles, we describe here a new inducible gene expression system in the thermophile Geobacillus kaustophilus HTA426. Six promoter regions in the HTA426 genome were identified and analyzed for expression profiles using β-galactosidase reporter assay. This analysis identified a promoter region upstream of a putative amylose-metabolizing gene cluster that directed high-level expression of the reporter gene. The expression was >280-fold that without a promoter and was further enhanced 12-fold by maltose addition. In association with a multicopy plasmid, this promoter region was used to express heterologous genes. Several genes, including a gene whose product was insoluble when expressed in Escherichia coli, were successfully expressed as soluble proteins, with yields of 0.16 to 59 mg/liter, and conferred new functions to G. kaustophilus strains. Remarkably, cellulase and α-amylase genes conferred the ability to degrade cellulose paper and insoluble starch at high temperatures, respectively, generating thermophiles with the potential to degrade plant biomass. Our results demonstrate that this novel expression system expands the potential applications of G. kaustophilus.
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27
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Lansky S, Salama R, Solomon VH, Belrhali H, Shoham Y, Shoham G. Crystallization and preliminary crystallographic analysis of Abp, a GH27 β-L-arabinopyranosidase from Geobacillus stearothermophilus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:695-9. [PMID: 23722857 DOI: 10.1107/s1744309113013705] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 05/17/2013] [Indexed: 11/11/2022]
Abstract
Geobacillus stearothermophilus T-6 is a thermophilic soil bacterium that possesses an extensive system for the utilization of hemicellulose. The bacterium produces a small number of endo-acting extracellular enzymes that cleave high-molecular-weight hemicellulolytic polymers into short decorated oligosaccharides, which are further hydrolysed into the respective sugar monomers by a battery of intracellular glycoside hydrolases. One of these intracellular processing enzymes is β-L-arabinopyranosidase (Abp), which is capable of removing β-L-arabinopyranose residues from naturally occurring arabino-polysaccharides. As arabino-polymers constitute a significant part of the hemicellulolytic content of plant biomass, their efficient enzymatic degradation presents an important challenge for many potential biotechnological applications. This aspect has led to an increasing interest in the biochemical characterization and structural analysis of this and related hemicellulases. Abp from G. stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized in our laboratory, as part of its complete structure-function study. The best crystals obtained for this enzyme belonged to the primitive orthorhombic space group P2(1)2(1)2(1), with average unit-cell parameters a = 107.7, b = 202.2, c = 287.3 Å. Full diffraction data sets to 2.3 Å resolution have been collected for both the wild-type enzyme and its D197A catalytic mutant from flash-cooled crystals at 100 K, using synchrotron radiation. These data are currently being used for a high-resolution three-dimensional structure determination of Abp.
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Affiliation(s)
- Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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28
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Lansky S, Alalouf O, Solomon V, Alhassid A, Govada L, Chayen NE, Chayan NE, Belrhali H, Shoham Y, Shoham G. Crystallization and preliminary crystallographic analysis of Axe2, an acetylxylan esterase from Geobacillus stearothermophilus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:430-4. [PMID: 23545652 DOI: 10.1107/s1744309113004260] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 02/12/2013] [Indexed: 11/10/2022]
Abstract
Acetylxylan esterases are part of the hemi-cellulolytic system of many microorganisms which utilize plant biomass for growth. Xylans, which are polymeric sugars that constitute a significant part of the plant biomass, are usually substituted with acetyl side groups attached at position 2 or 3 of the xylose backbone units. Acetylxylan esterases hydrolyse the ester linkages of the xylan acetyl groups and thus improve the ability of main-chain hydrolysing enzymes to break down the sugar backbone units. As such, these enzymes play an important part in the hemi-cellulolytic utilization system of many microorganisms that use plant biomass for growth. Interest in the biochemical characterization and structural analysis of these enzymes stems from their numerous potential biotechnological applications. An acetylxylan esterase (Axe2) of this type from Geobacillus stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized. One of the crystal forms obtained (RB1) belonged to the tetragonal space group I422, with unit-cell parameters a = b = 110.2, c = 213.1 Å. A full diffraction data set was collected to 1.85 Å resolution from flash-cooled crystals of the wild-type enzyme at 100 K using synchrotron radiation. A selenomethionine derivative of Axe2 has also been prepared and crystallized for single-wavelength anomalous diffraction experiments. The crystals of the selenomethionine-derivatized Axe2 appeared to be isomorphous to those of the wild-type enzyme and enabled the measurement of a full 1.85 Å resolution diffraction data set at the selenium absorption edge and a full 1.70 Å resolution data set at a remote wavelength. These data are currently being used for three-dimensional structure determination of the Axe2 protein.
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Affiliation(s)
- Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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