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McGregor NS, de Boer C, Foucart QPO, Beenakker T, Offen WA, Codée JDC, Willems LI, Overkleeft HS, Davies GJ. A Multiplexing Activity-Based Protein-Profiling Platform for Dissection of a Native Bacterial Xyloglucan-Degrading System. ACS CENTRAL SCIENCE 2023; 9:2306-2314. [PMID: 38161374 PMCID: PMC10755729 DOI: 10.1021/acscentsci.3c00831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/26/2023] [Accepted: 11/06/2023] [Indexed: 01/03/2024]
Abstract
Bacteria and yeasts grow on biomass polysaccharides by expressing and excreting a complex array of glycoside hydrolase (GH) enzymes. Identification and annotation of such GH pools, which are valuable commodities for sustainable energy and chemistries, by conventional means (genomics, proteomics) are complicated, as primary sequence or secondary structure alignment with known active enzymes is not always predictive for new ones. Here we report a "low-tech", easy-to-use, and sensitive multiplexing activity-based protein-profiling platform to characterize the xyloglucan-degrading GH system excreted by the soil saprophyte, Cellvibrio japonicus, when grown on xyloglucan. A suite of activity-based probes bearing orthogonal fluorophores allows for the visualization of accessory exo-acting glycosidases, which are then identified using biotin-bearing probes. Substrate specificity of xyloglucanases is directly revealed by imbuing xyloglucan structural elements into bespoke activity-based probes. Our ABPP platform provides a highly useful tool to dissect xyloglucan-degrading systems from various sources and to rapidly select potentially useful ones. The observed specificity of the probes moreover bodes well for the study of other biomass polysaccharide-degrading systems, by modeling probe structures to those of desired substrates.
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Affiliation(s)
| | - Casper de Boer
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Quentin P. O. Foucart
- Department
of Chemistry, The University of York, Heslington, York YO10 5DD, United
Kingdom
| | - Thomas Beenakker
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Wendy A. Offen
- Department
of Chemistry, The University of York, Heslington, York YO10 5DD, United
Kingdom
| | - Jeroen D. C. Codée
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Lianne I. Willems
- York
Structural Biology Laboratory and York Biomedical Research Institute,
Department of Chemistry, University of York, Heslington, York YO10 5DD, United
Kingdom
| | - Herman S. Overkleeft
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Gideon J. Davies
- Department
of Chemistry, The University of York, Heslington, York YO10 5DD, United
Kingdom
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2
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Stratilová B, Šesták S, Stratilová E, Vadinová K, Kozmon S, Hrmova M. Engineering of substrate specificity in a plant cell-wall modifying enzyme through alterations of carboxyl-terminal amino acid residues. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1529-1544. [PMID: 37658783 DOI: 10.1111/tpj.16435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/07/2023] [Accepted: 08/12/2023] [Indexed: 09/05/2023]
Abstract
Structural determinants of substrate recognition remain inadequately defined in broad specific cell-wall modifying enzymes, termed xyloglucan xyloglucosyl transferases (XETs). Here, we investigate the Tropaeolum majus seed TmXET6.3 isoform, a member of the GH16_20 subfamily of the GH16 network. This enzyme recognises xyloglucan (XG)-derived donors and acceptors, and a wide spectrum of other chiefly saccharide substrates, although it lacks the activity with homogalacturonan (pectin) fragments. We focus on defining the functionality of carboxyl-terminal residues in TmXET6.3, which extend acceptor binding regions in the GH16_20 subfamily but are absent in the related GH16_21 subfamily. Site-directed mutagenesis using double to quintuple mutants in the carboxyl-terminal region - substitutions emulated on barley XETs recognising the XG/penta-galacturonide acceptor substrate pair - demonstrated that this activity could be gained in TmXET6.3. We demonstrate the roles of semi-conserved Arg238 and Lys237 residues, introducing a net positive charge in the carboxyl-terminal region (which complements a negative charge of the acidic penta-galacturonide) for the transfer of xyloglucan fragments. Experimental data, supported by molecular modelling of TmXET6.3 with the XG oligosaccharide donor and penta-galacturonide acceptor substrates, indicated that they could be accommodated in the active site. Our findings support the conclusion on the significance of positively charged residues at the carboxyl terminus of TmXET6.3 and suggest that a broad specificity could be engineered via modifications of an acceptor binding site. The definition of substrate specificity in XETs should prove invaluable for defining the structure, dynamics, and function of plant cell walls, and their metabolism; these data could be applicable in various biotechnologies.
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Affiliation(s)
- Barbora Stratilová
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538, Bratislava, Slovakia
| | - Sergej Šesták
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538, Bratislava, Slovakia
| | - Eva Stratilová
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538, Bratislava, Slovakia
| | - Kristína Vadinová
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538, Bratislava, Slovakia
| | - Stanislav Kozmon
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538, Bratislava, Slovakia
| | - Maria Hrmova
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Waite Research Precinct, Glen Osmond, South Australia, 5064, Australia
- Jiangsu Collaborative Innovation Centre for Regional Modern Agriculture and Environmental Protection, School of Life Science, Huaiyin Normal University, Huai'an, 223300, China
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3
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Jian X, Li C, Feng X. Strategies for modulating transglycosylation activity, substrate specificity, and product polymerization degree of engineered transglycosylases. Crit Rev Biotechnol 2023; 43:1284-1298. [PMID: 36154438 DOI: 10.1080/07388551.2022.2105687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 06/21/2022] [Indexed: 01/18/2023]
Abstract
Glycosides are widely used in many fields due to their favorable biological activity. The traditional plant extractions and chemical methods for glycosides production are limited by environmentally unfriendly, laborious protecting group strategies and low yields. Alternatively, enzymatic glycosylation has drawn special attention due to its mild reaction conditions, high catalytic efficiency, and specific stereo-/regioselectivity. Glycosyltransferases (GTs) and retaining glycoside hydrolases (rGHs) are two major enzymes for the formation of glycosidic linkages. Therein GTs generally use nucleotide phosphate activated donors. In contrast, GHs can use broader simple and affordable glycosyl donors, showing great potential in industrial applications. However, most rGHs mainly show hydrolysis activity and only a few rGHs, namely non-Leloir transglycosylases (TGs), innately present strong transglycosylation activities. To address this problem, various strategies have recently been developed to successfully tailor rGHs to alleviate their hydrolysis activity and obtain the engineered TGs. This review summarizes the current modification strategies in TGs engineering, with a special focus on transglycosylation activity enhancement, substrate specificity modulation, and product polymerization degree distribution, which provides a reference for exploiting the transglycosylation potentials of rGHs.
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Affiliation(s)
- Xing Jian
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Chun Li
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
- Center for Synthetic & Systems Biology, Tsinghua University, Beijing, China
| | - Xudong Feng
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
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4
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Stratilová B, Stratilová E, Hrmova M, Kozmon S. Definition of the Acceptor Substrate Binding Specificity in Plant Xyloglucan Endotransglycosylases Using Computational Chemistry. Int J Mol Sci 2022; 23:ijms231911838. [PMID: 36233140 PMCID: PMC9569819 DOI: 10.3390/ijms231911838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
Xyloglucan endotransglycosylases (XETs) play key roles in the remodelling and reconstruction of plant cell walls. These enzymes catalyse homo-transglycosylation reactions with xyloglucan-derived donor and acceptor substrates and hetero-transglycosylation reactions with a variety of structurally diverse polysaccharides. In this work, we describe the basis of acceptor substrate binding specificity in non-specific Tropaeolum majus (TmXET6.3) and specific Populus tremula x tremuloides (PttXET16A) XETs, using molecular docking and molecular dynamics (MD) simulations combined with binding free energy calculations. The data indicate that the enzyme-donor (xyloglucan heptaoligosaccharide or XG-OS7)/acceptor complexes with the linear acceptors, where a backbone consisted of glucose (Glc) moieties linked via (1,4)- or (1,3)-β-glycosidic linkages, were bound stably in the active sites of TmXET6.3 and PttXET16A. Conversely, the acceptors with the (1,6)-β-linked Glc moieties were bound stably in TmXET6.3 but not in PttXET16A. When in the (1,4)-β-linked Glc containing acceptors, the saccharide moieties were replaced with mannose or xylose, they bound stably in TmXET6.3 but lacked stability in PttXET16A. MD simulations of the XET-donor/acceptor complexes with acceptors derived from (1,4;1,3)-β-glucans highlighted the importance of (1,3)-β-glycosidic linkages and side chain positions in the acceptor substrates. Our findings explain the differences in acceptor binding specificity between non-specific and specific XETs and associate theoretical to experimental data.
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Affiliation(s)
- Barbora Stratilová
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia
| | - Eva Stratilová
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia
| | - Maria Hrmova
- Jiangsu Collaborative Innovation Centre for Regional Modern Agriculture and Environmental Protection, School of Life Science, Huaiyin Normal University, Huai’an 223300, China
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064, Australia
- Correspondence: (M.H.); (S.K.)
| | - Stanislav Kozmon
- Institute of Chemistry, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia
- Medical Vision o.z., SK-82108 Bratislava, Slovakia
- Correspondence: (M.H.); (S.K.)
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5
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Hrmova M, Stratilová B, Stratilová E. Broad Specific Xyloglucan:Xyloglucosyl Transferases Are Formidable Players in the Re-Modelling of Plant Cell Wall Structures. Int J Mol Sci 2022; 23:ijms23031656. [PMID: 35163576 PMCID: PMC8836008 DOI: 10.3390/ijms23031656] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 01/27/2023] Open
Abstract
Plant xyloglucan:xyloglucosyl transferases, known as xyloglucan endo-transglycosylases (XETs) are the key players that underlie plant cell wall dynamics and mechanics. These fundamental roles are central for the assembly and modifications of cell walls during embryogenesis, vegetative and reproductive growth, and adaptations to living environments under biotic and abiotic (environmental) stresses. XET enzymes (EC 2.4.1.207) have the β-sandwich architecture and the β-jelly-roll topology, and are classified in the glycoside hydrolase family 16 based on their evolutionary history. XET enzymes catalyse transglycosylation reactions with xyloglucan (XG)-derived and other than XG-derived donors and acceptors, and this poly-specificity originates from the structural plasticity and evolutionary diversification that has evolved through expansion and duplication. In phyletic groups, XETs form the gene families that are differentially expressed in organs and tissues in time- and space-dependent manners, and in response to environmental conditions. Here, we examine higher plant XET enzymes and dissect how their exclusively carbohydrate-linked transglycosylation catalytic function inter-connects complex plant cell wall components. Further, we discuss progress in technologies that advance the knowledge of plant cell walls and how this knowledge defines the roles of XETs. We construe that the broad specificity of the plant XETs underscores their roles in continuous cell wall restructuring and re-modelling.
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Affiliation(s)
- Maria Hrmova
- Jiangsu Collaborative Innovation Centre for Regional Modern Agriculture and Environmental Protection, School of Life Science, Huaiyin Normal University, Huai’an 223300, China
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064, Australia
- Correspondence: ; Tel.: +61-8-8313-0775
| | - Barbora Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia; (B.S.); (E.S.)
- Faculty of Natural Sciences, Department of Physical and Theoretical Chemistry, Comenius University, SK-84215 Bratislava, Slovakia
| | - Eva Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, SK-84538 Bratislava, Slovakia; (B.S.); (E.S.)
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6
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Shinohara N, Nishitani K. Cryogenian Origin and Subsequent Diversification of the Plant Cell-Wall Enzyme XTH Family. PLANT & CELL PHYSIOLOGY 2021; 62:1874-1889. [PMID: 34197607 PMCID: PMC8711696 DOI: 10.1093/pcp/pcab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/24/2021] [Accepted: 07/01/2021] [Indexed: 05/22/2023]
Abstract
All land plants encode large multigene families of xyloglucan endotransglucosylase/hydrolases (XTHs), plant-specific enzymes that cleave and reconnect plant cell-wall polysaccharides. Despite the ubiquity of these enzymes, considerable uncertainty remains regarding the evolutionary history of the XTH family. Phylogenomic and comparative analyses in this study traced the non-plant origins of the XTH family to Alphaproteobacteria ExoKs, bacterial enzymes involved in loosening biofilms, rather than Firmicutes licheninases, plant biomass digesting enzymes, as previously supposed. The relevant horizontal gene transfer (HGT) event was mapped to the divergence of non-swimming charophycean algae in the Cryogenian geological period. This HGT event was the likely origin of charophycean EG16-2s, which are putative intermediates between ExoKs and XTHs. Another HGT event in the Cryogenian may have led from EG16-2s or ExoKs to fungal Congo Red Hypersensitive proteins (CRHs) to fungal CRHs, enzymes that cleave and reconnect chitin and glucans in fungal cell walls. This successive transfer of enzyme-encoding genes may have supported the adaptation of plants and fungi to the ancient icy environment by facilitating their sessile lifestyles. Furthermore, several protein evolutionary steps, including coevolution of substrate-interacting residues and putative intra-family gene fusion, occurred in the land plant lineage and drove diversification of the XTH family. At least some of those events correlated with the evolutionary gain of broader substrate specificities, which may have underpinned the expansion of the XTH family by enhancing duplicated gene survival. Together, this study highlights the Precambrian evolution of life and the mode of multigene family expansion in the evolutionary history of the XTH family.
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Affiliation(s)
- Naoki Shinohara
- *Corresponding authors: Naoki Shinohara, E-mail, ; Kazuhiko Nishitani, E-mail,
| | - Kazuhiko Nishitani
- *Corresponding authors: Naoki Shinohara, E-mail, ; Kazuhiko Nishitani, E-mail,
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7
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Xin A, Fry SC. Cutin:xyloglucan transacylase (CXT) activity covalently links cutin to a plant cell-wall polysaccharide. JOURNAL OF PLANT PHYSIOLOGY 2021; 262:153446. [PMID: 34051591 DOI: 10.1016/j.jplph.2021.153446] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 05/26/2023]
Abstract
The shoot epidermal cell wall in land-plants is associated with a polyester, cutin, which controls water loss and possibly organ expansion. Covalent bonds between cutin and its neighbouring cell-wall polysaccharides have long been proposed. However, the lack of biochemical evidence makes cutin-polysaccharide linkages largely conjectural. Here we optimised a portfolio of radiochemical assays to look for cutin-polysaccharide ester bonds in the epidermis of pea epicotyls, ice-plant leaves and tomato fruits, based on the hypothesis that a transacylase remodels cutin in a similar fashion to cutin synthase and cutin:cutin transacylase activities. Through in-situ enzyme assays and chemical degradations coupled with chromatographic analysis of the 3H-labelled products, we observed that among several wall-related oligosaccharides tested, only a xyloglucan oligosaccharide ([3H]XXXGol) could acquire ester-bonds from endogenous cutin, suggesting a cutin:xyloglucan transacylase (CXT). CXT activity was heat-labile, time-dependent, and maximal at near-neutral pH values. In-situ CXT activity peaked in nearly fully expanded tomato fruits and ice-plant leaves. CXT activity positively correlated with organ growth rate, suggesting that it contributes to epidermal integrity during rapid expansion. This study uncovers hitherto unappreciated re-structuring processes in the plant epidermis and provides a step towards the identification of CXT and its engineering for biotechnological applications.
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Affiliation(s)
- Anzhou Xin
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Stephen C Fry
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK.
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8
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Seven M, Derman ÜC, Harvey AJ. Enzymatic characterization of ancestral/group-IV clade xyloglucan endotransglycosylase/hydrolase enzymes reveals broad substrate specificities. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1660-1673. [PMID: 33825243 DOI: 10.1111/tpj.15262] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 05/14/2023]
Abstract
Xyloglucan endotransglycosylase/hydrolase (XTH) enzymes play important roles in cell wall remodelling. Although previous studies have shown a pathway of evolution for XTH genes from bacterial licheninases, through plant endoglucanases (EG16), the order of development within the phylogenetic clades of true XTHs is yet to be elucidated. In addition, recent studies have revealed interesting and potentially useful patterns of transglycosylation beyond the standard xyloglucan-xyloglucan donor/acceptor substrate activities. To study evolutionary relationships and to search for enzymes with useful broad substrate specificities, genes from the 'ancestral' XTH clade of two monocots, Brachypodium distachyon and Triticum aestivum, and two eudicots, Arabidopsis thaliana and Populus tremula, were investigated. Specific activities of the heterologously produced enzymes showed remarkably broad substrate specificities. All the enzymes studied had high activity with the cellulose analogue HEC (hydroxyethyl cellulose) as well as with mixed-link β-glucan as donor substrates, when compared with the standard xyloglucan. Even more surprising was the wide range of acceptor substrates that these enzymes were able to catalyse reactions with, opening a broad range of possible roles for these enzymes, both within plants and in industrial, pharmaceutical and medical fields. Genome screening and expression analyses unexpectedly revealed that genes from this clade were found only in angiosperm genomes and were predominantly or solely expressed in reproductive tissues. We therefore posit that this phylogenetic group is significantly different and should be renamed as the group-IV clade.
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Affiliation(s)
- Merve Seven
- Department of Genetics and Bioengineering, Yeditepe University, Istanbul, 34755, Turkey
| | - Ü Cem Derman
- Department of Genetics and Bioengineering, Yeditepe University, Istanbul, 34755, Turkey
| | - Andrew J Harvey
- Department of Genetics and Bioengineering, Yeditepe University, Istanbul, 34755, Turkey
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9
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Herburger K, Franková L, Pičmanová M, Xin A, Meulewaeter F, Hudson A, Fry SC. Defining natural factors that stimulate and inhibit cellulose:xyloglucan hetero-transglucosylation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1549-1565. [PMID: 33314395 PMCID: PMC8611796 DOI: 10.1111/tpj.15131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/24/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Certain transglucanases can covalently graft cellulose and mixed-linkage β-glucan (MLG) as donor substrates onto xyloglucan as acceptor substrate and thus exhibit cellulose:xyloglucan endotransglucosylase (CXE) and MLG:xyloglucan endotransglucosylase (MXE) activities in vivo and in vitro. However, missing information on factors that stimulate or inhibit these hetero-transglucosylation reactions limits our insight into their biological functions. To explore factors that influence hetero-transglucosylation, we studied Equisetum fluviatile hetero-trans-β-glucanase (EfHTG), which exhibits both CXE and MXE activity, exceeding its xyloglucan:xyloglucan homo-transglucosylation (XET) activity. Enzyme assays employed radiolabelled and fluorescently labelled oligomeric acceptor substrates, and were conducted in vitro and in cell walls (in situ). With whole denatured Equisetum cell walls as donor substrate, exogenous EfHTG (extracted from Equisetum or produced in Pichia) exhibited all three activities (CXE, MXE, XET) in competition with each other. Acting on pure cellulose as donor substrate, the CXE action of Pichia-produced EfHTG was up to approximately 300% increased by addition of methanol-boiled Equisetum extracts; there was no similar effect when the same enzyme acted on soluble donors (MLG or xyloglucan). The methanol-stable factor is proposed to be expansin-like, a suggestion supported by observations of pH dependence. Screening numerous low-molecular-weight compounds for hetero-transglucanase inhibition showed that cellobiose was highly effective, inhibiting the abundant endogenous CXE and MXE (but not XET) action in Equisetum internodes. Furthermore, cellobiose retarded Equisetum stem elongation, potentially owing to its effect on hetero-transglucosylation reactions. This work provides insight and tools to further study the role of cellulose hetero-transglucosylation in planta by identifying factors that govern this reaction.
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Affiliation(s)
- Klaus Herburger
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
- Present address:
Section for Plant GlycobiologyDepartment of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg1871Denmark
| | - Lenka Franková
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Martina Pičmanová
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Anzhou Xin
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Frank Meulewaeter
- BBCC Innovation Center Gent – Trait ResearchBASFGent (Zwijnaarde)9052Belgium
| | - Andrew Hudson
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
| | - Stephen C. Fry
- The Edinburgh Cell Wall GroupInstitute of Molecular Plant SciencesSchool of Biological SciencesThe University of EdinburghEdinburghEH9 3BFUK
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10
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Stratilová B, Kozmon S, Stratilová E, Hrmova M. Plant Xyloglucan Xyloglucosyl Transferases and the Cell Wall Structure: Subtle but Significant. Molecules 2020; 25:E5619. [PMID: 33260399 PMCID: PMC7729885 DOI: 10.3390/molecules25235619] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022] Open
Abstract
Plant xyloglucan xyloglucosyl transferases or xyloglucan endo-transglycosylases (XET; EC 2.4.1.207) catalogued in the glycoside hydrolase family 16 constitute cell wall-modifying enzymes that play a fundamental role in the cell wall expansion and re-modelling. Over the past thirty years, it has been established that XET enzymes catalyse homo-transglycosylation reactions with xyloglucan (XG)-derived substrates and hetero-transglycosylation reactions with neutral and charged donor and acceptor substrates other than XG-derived. This broad specificity in XET isoforms is credited to a high degree of structural and catalytic plasticity that has evolved ubiquitously in algal, moss, fern, basic Angiosperm, monocot, and eudicot enzymes. These XET isoforms constitute gene families that are differentially expressed in tissues in time- and space-dependent manners during plant growth and development, and in response to biotic and abiotic stresses. Here, we discuss the current state of knowledge of broad specific plant XET enzymes and how their inherently carbohydrate-based transglycosylation reactions tightly link with structural diversity that underlies the complexity of plant cell walls and their mechanics. Based on this knowledge, we conclude that multi- or poly-specific XET enzymes are widespread in plants to allow for modifications of the cell wall structure in muro, a feature that implements the multifaceted roles in plant cells.
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Affiliation(s)
- Barbora Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84538 Bratislava, Slovakia; (B.S.); (S.K.); (E.S.)
- Faculty of Natural Sciences, Department of Physical and Theoretical Chemistry, Comenius University, Mlynská Dolina, SK-84215 Bratislava, Slovakia
| | - Stanislav Kozmon
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84538 Bratislava, Slovakia; (B.S.); (S.K.); (E.S.)
| | - Eva Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84538 Bratislava, Slovakia; (B.S.); (S.K.); (E.S.)
| | - Maria Hrmova
- School of Life Science, Huaiyin Normal University, Huai’an 223300, China
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA 5064, Australia
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11
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Stratilová B, Šesták S, Mravec J, Garajová S, Pakanová Z, Vadinová K, Kučerová D, Kozmon S, Schwerdt JG, Shirley N, Stratilová E, Hrmova M. Another building block in the plant cell wall: Barley xyloglucan xyloglucosyl transferases link covalently xyloglucan and anionic oligosaccharides derived from pectin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:752-767. [PMID: 32799357 DOI: 10.1111/tpj.14964] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/17/2020] [Accepted: 07/29/2020] [Indexed: 05/27/2023]
Abstract
We report on the homo- and hetero-transglycosylation activities of the HvXET3 and HvXET4 xyloglucan xyloglucosyl transferases (XET; EC 2.4.1.207) from barley (Hordeum vulgare L.), and the visualisation of these activities in young barley roots using Alexa Fluor 488-labelled oligosaccharides. We discover that these isozymes catalyse the transglycosylation reactions with the chemically defined donor and acceptor substrates, specifically with the xyloglucan donor and the penta-galacturonide [α(1-4)GalAp]5 acceptor - the homogalacturonan (pectin) fragment. This activity is supported by 3D molecular models of HvXET3 and HvXET4 with the docked XXXG donor and [α(1-4)GalAp]5 acceptor substrates at the -4 to +5 subsites in the active sites. Comparative sequence analyses of barley isoforms and seed-localised TmXET6.3 from nasturtium (Tropaeolum majus L.) permitted the engineering of mutants of TmXET6.3 that could catalyse the hetero-transglycosylation reaction with the xyloglucan/[α(1-4)GalAp]5 substrate pair, while wild-type TmXET6.3 lacked this activity. Expression data obtained by real-time quantitative polymerase chain reaction of HvXET transcripts and a clustered heatmap of expression profiles of the gene family revealed that HvXET3 and HvXET6 co-expressed but did not share the monophyletic origin. Conversely, HvXET3 and HvXET4 shared this relationship, when we examined the evolutionary history of 419 glycoside hydrolase 16 family members, spanning monocots, eudicots and a basal Angiosperm. The discovered hetero-transglycosylation activity in HvXET3 and HvXET4 with the xyloglucan/[α(1-4)GalAp]5 substrate pair is discussed against the background of roles of xyloglucan-pectin heteropolymers and how they may participate in spatial patterns of cell wall formation and re-modelling, and affect the structural features of walls.
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Affiliation(s)
- Barbora Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
- Faculty of Natural Sciences, Department of Physical and Theoretical Chemistry, Comenius University, Mlynská dolina, Bratislava, SK-842 15, Slovakia
| | - Sergej Šesták
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg-C, 1871, Denmark
| | - Soňa Garajová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Zuzana Pakanová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Kristína Vadinová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Danica Kučerová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Stanislav Kozmon
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Julian G Schwerdt
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Neil Shirley
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Eva Stratilová
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, SK-84538, Slovakia
| | - Maria Hrmova
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia
- School of Life Sciences, Huaiyin Normal University, Huai'an, 223300, China
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12
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Herburger K, Franková L, Sanhueza D, Roig-Sanchez S, Meulewaeter F, Hudson A, Thomson A, Laromaine A, Budtova T, Fry SC. Enzymically attaching oligosaccharide-linked 'cargoes' to cellulose and other commercial polysaccharides via stable covalent bonds. Int J Biol Macromol 2020; 164:4359-4369. [PMID: 32918959 DOI: 10.1016/j.ijbiomac.2020.09.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/25/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
The Equisetum enzyme hetero-trans-β-glucanase (HTG) covalently grafts native plant cellulose (donor-substrate) to xyloglucan (acceptor-substrate), potentially offering a novel 'green' method of cellulose functionalisation. However, the range of cellulosic and non-cellulosic donor substrates that can be utilised by HTG is unknown, limiting our insight into its biotechnological potential. Here we show that HTG binds all celluloses tested (papers, tissues, hydrogels, bacterial cellulose) to radioactively- or fluorescently-labelled xyloglucan-heptasaccharide (XXXGol; acceptor-substrate). Glycol-chitin, glycol-chitosan and chitosan also acted as donor substrates but less effectively than cellulose. Cellulose-XXXGol conjugates were formed throughout the volume of a block of hydrogel, demonstrating penetration. Plant-derived celluloses (cellulose Iβ) became more effective donor-substrates after 'mercerisation' in ≥3 M NaOH; the opposite was true for bacterial cellulose Iα. Cellulose-XXXGol bonds resisted boiling 6 M NaOH, demonstrating strong glycosidic bonding. In conclusion, HTG stably grafts native and processed celluloses to xyloglucan-oligosaccharides, which may carry valuable 'cargoes', exemplified by sulphorhodamine. We thus demonstrate HTG's biotechnological potential to modify various cellulose-based substrates such as textiles, pulps, papers, packaging, sanitary products and hydrogels.
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Affiliation(s)
- Klaus Herburger
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom.
| | - Lenka Franková
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Dayan Sanhueza
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Soledad Roig-Sanchez
- Institut de Ciència de Materials de Barcelona (ICMAB), Campus UAB, Bellaterra, Catalonia E-08193, Spain
| | - Frank Meulewaeter
- BASF, BBCC Innovation Center Gent - Trait Research, 9052 Gent (Zwijnaarde), Belgium
| | - Andrew Hudson
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Axel Thomson
- Edinburgh Innovations, The University of Edinburgh, Murchison House, King's Buildings, Edinburgh EH9 3BF, United Kingdom
| | - Anna Laromaine
- Institut de Ciència de Materials de Barcelona (ICMAB), Campus UAB, Bellaterra, Catalonia E-08193, Spain
| | - Tatiana Budtova
- MINES ParisTech, PSL Research University, CEMEF - Center for Materials Forming, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France
| | - Stephen C Fry
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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Holland C, Simmons TJ, Meulewaeter F, Hudson A, Fry SC. Three highly acidic Equisetum XTHs differ from hetero-trans-β-glucanase in donor substrate specificity and are predominantly xyloglucan homo-transglucosylases. JOURNAL OF PLANT PHYSIOLOGY 2020; 251:153210. [PMID: 32544741 DOI: 10.1016/j.jplph.2020.153210] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 05/20/2020] [Accepted: 05/24/2020] [Indexed: 05/27/2023]
Abstract
Transglycanases are enzymes that remodel the primary cell wall in plants, potentially loosening and/or strengthening it. Xyloglucan endotransglucosylase (XET; EC 2.4.1.207), ubiquitous in land plants, is a homo-transglucanase activity (donor, xyloglucan; acceptor, xyloglucan) exhibited by XTH (xyloglucan endotransglucosylase/hydrolase) proteins. By contrast, hetero-trans-β-glucanase (HTG) is the only known enzyme that is preferentially a hetero-transglucanase. Its two main hetero-transglucanase activities are MLG : xyloglucan endotransglucosylase (MXE) and cellulose : xyloglucan endotransglucosylase (CXE). HTG is highly acidic and found only in the evolutionarily isolated genus of fern-allies, Equisetum. We now report genes for three new highly acidic HTG-related XTHs in E. fluviatile (EfXTH-A, EfXTH-H and EfXTH-I). We expressed them heterologously in Pichia and tested the encoded proteins' enzymic activities to determine whether their acidity and/or their Equisetum-specific sequences might confer high hetero-transglucanase activity. Untransformed Pichia was found to secrete MLG-degrading enzyme(s), which had to be removed for reliable MXE assays. All three acidic EfXTHs exhibited very predominantly XET activity, although low but measurable hetero-transglucanase activities (MXE and CXE) were also detected in EfXTH-H and EfXTH-I. We conclude that the extremely high hetero-transglucanase activities of Equisetum HTG are not emulated by similarly acidic Equisetum XTHs that share up to 55.5% sequence identity with HTG.
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Affiliation(s)
- Claire Holland
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Thomas J Simmons
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Frank Meulewaeter
- BASF Innovation Center Gent- Trait Research, Technologiepark-Zwijnaarde, 9052 Gent, Belgium
| | - Andrew Hudson
- Institute of Molecular Plant Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Stephen C Fry
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK.
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14
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Herburger K, Franková L, Pičmanová M, Loh JW, Valenzuela-Ortega M, Meulewaeter F, Hudson AD, French CE, Fry SC. Hetero-trans-β-Glucanase Produces Cellulose-Xyloglucan Covalent Bonds in the Cell Walls of Structural Plant Tissues and Is Stimulated by Expansin. MOLECULAR PLANT 2020; 13:1047-1062. [PMID: 32376294 PMCID: PMC7339142 DOI: 10.1016/j.molp.2020.04.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 04/17/2020] [Accepted: 04/28/2020] [Indexed: 05/19/2023]
Abstract
Current cell-wall models assume no covalent bonding between cellulose and hemicelluloses such as xyloglucan or mixed-linkage β-d-glucan (MLG). However, Equisetum hetero-trans-β-glucanase (HTG) grafts cellulose onto xyloglucan oligosaccharides (XGOs) - and, we now show, xyloglucan polysaccharide - in vitro, thus exhibiting CXE (cellulose:xyloglucan endotransglucosylase) activity. In addition, HTG also catalyzes MLG-to-XGO bonding (MXE activity). In this study, we explored the CXE action of HTG in native plant cell walls and tested whether expansin exposes cellulose to HTG by disrupting hydrogen bonds. To quantify and visualize CXE and MXE action, we assayed the sequential release of HTG products from cell walls pre-labeled with substrate mimics. We demonstrated covalent cellulose-xyloglucan bonding in plant cell walls and showed that CXE and MXE action was up to 15% and 60% of total transglucanase action, respectively, and peaked in aging, strengthening tissues: CXE in xylem and cells bordering intercellular canals and MXE in sclerenchyma. Recombinant bacterial expansin (EXLX1) strongly augmented CXE activity in vitro. CXE and MXE action in living Equisetum structural tissues potentially strengthens stems, while expansin might augment the HTG-catalyzed CXE reaction, thereby allowing efficient CXE action in muro. Our methods will enable surveys for comparable reactions throughout the plant kingdom. Furthermore, engineering similar hetero-polymer formation into angiosperm crop plants may improve certain agronomic traits such as lodging tolerance.
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Affiliation(s)
- Klaus Herburger
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom.
| | - Lenka Franková
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Martina Pičmanová
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Jia Wooi Loh
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Marcos Valenzuela-Ortega
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Frank Meulewaeter
- BASF, BBCC Innovation Center Gent - Trait Research, 9052 Gent (Zwijnaarde), Belgium
| | - Andrew D Hudson
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Christopher E French
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom; Zhejiang University-University of Edinburgh Joint Research Centre for Engineering Biology, Zhejiang University, Haining, Zhejiang 314400, China
| | - Stephen C Fry
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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15
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Small design from big alignment: engineering proteins with multiple sequence alignment as the starting point. Biotechnol Lett 2020; 42:1305-1315. [PMID: 32430802 DOI: 10.1007/s10529-020-02914-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/14/2020] [Indexed: 02/08/2023]
Abstract
Multiple sequence alignment (MSA) is a fundamental way to gain information that cannot be obtained from the analysis of any individual sequence included in the alignment. It provides ways to investigate the relationship between sequence and function from a perspective of evolution. Thus, the MSA of proteins can be employed as a reference for protein engineering. In this paper, we reviewed the recent advances to highlight how protein engineering was benefited from the MSA of proteins. These methods include (1) engineering the thermostability or solubility of proteins by making it closer to the consensus sequence of the alignment through introducing site mutations; (2) structure-based engineering proteins with comparative modeling; (3) creating paleoenzymes featured with high thermostability and promiscuity by constructing the ancestral sequences derived from multiple sequence alignment; and (4) incorporating site-mutations targeting the evolutionarily coupled sites identified from multiple sequence alignment.
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