1
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Mei X, Tao W, Sun H, Liu G, Chen G, Zhang Y, Xue C, Chang Y. Characterization and structural identification of a novel alginate-specific carbohydrate-binding module (CBM): The founding member of a new CBM family. Int J Biol Macromol 2024; 277:134221. [PMID: 39069041 DOI: 10.1016/j.ijbiomac.2024.134221] [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: 06/10/2024] [Revised: 07/22/2024] [Accepted: 07/25/2024] [Indexed: 07/30/2024]
Abstract
Alginate is a commercially important polysaccharide widely distributed in brown algae. Carbohydrate-binding modules (CBMs), a class of commonly used polysaccharide-binding proteins, have greatly facilitated the investigations of polysaccharides. Few alginate-binding CBMs have been hitherto reported and structurally characterized. Herein, an unknown domain from a potential PL6 family alginate lyase in the marine bacterium Vibrio breoganii was discovered and recombinantly expressed. The obtained protein, designated VbCBM106, displayed the favorable specificity to alginate. The unique sequence and well-defined function of VbCBM106 reveal a new CBM family (CBM106). Moreover, the structure of VbCBM106 was determined at a 1.5 Å resolution by the X-ray crystallography, which shows a typical β-sandwich fold comprised of two antiparallel β-sheets. Site-directed mutagenesis assays confirmed that positively charged polar residues are crucial for the ligand binding of VbCBM106. The discovery of VbCBM106 enriches the toolbox of alginate-binding proteins, and the elucidation of critical residues would guide the future practical applications of VbCBM106.
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Affiliation(s)
- Xuanwei Mei
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Wenwen Tao
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Haitao Sun
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Guanchen Liu
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Guangning Chen
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Yuying Zhang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Changhu Xue
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China
| | - Yaoguang Chang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao, 266404, China.
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2
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You Y, Kong H, Li C, Gu Z, Ban X, Li Z. Carbohydrate binding modules: Compact yet potent accessories in the specific substrate binding and performance evolution of carbohydrate-active enzymes. Biotechnol Adv 2024; 73:108365. [PMID: 38677391 DOI: 10.1016/j.biotechadv.2024.108365] [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: 12/11/2023] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024]
Abstract
Carbohydrate binding modules (CBMs) are independent non-catalytic domains widely found in carbohydrate-active enzymes (CAZymes), and they play an essential role in the substrate binding process of CAZymes by guiding the appended catalytic modules to the target substrates. Owing to their precise recognition and selective affinity for different substrates, CBMs have received increasing research attention over the past few decades. To date, CBMs from different origins have formed a large number of families that show a variety of substrate types, structural features, and ligand recognition mechanisms. Moreover, through the modification of specific sites of CBMs and the fusion of heterologous CBMs with catalytic domains, improved enzymatic properties and catalytic patterns of numerous CAZymes have been achieved. Based on cutting-edge technologies in computational biology, gene editing, and protein engineering, CBMs as auxiliary components have become portable and efficient tools for the evolution and application of CAZymes. With the aim to provide a theoretical reference for the functional research, rational design, and targeted utilization of novel CBMs in the future, we systematically reviewed the function-related characteristics and potentials of CAZyme-derived CBMs in this review, including substrate recognition and binding mechanisms, non-catalytic contributions to enzyme performances, module modifications, and innovative applications in various fields.
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Affiliation(s)
- Yuxian You
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Haocun Kong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Caiming Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhengbiao Gu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiaofeng Ban
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Zhaofeng Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China.
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3
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Norlander S, Jasilionis A, Allahgholi L, Wennerberg C, Grey C, Adlercreutz P, Karlsson EN. Inter domain linker region affects properties of CBM6 in GH5_34 arabinoxylanases and alters oligosaccharide product profile. Glycobiology 2024; 34:cwae048. [PMID: 38982733 PMCID: PMC11246198 DOI: 10.1093/glycob/cwae048] [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: 09/11/2023] [Revised: 05/22/2024] [Accepted: 07/08/2024] [Indexed: 07/11/2024] Open
Abstract
Understanding the relation between enzyme domain structure and catalytic activity is crucial for optimal engineering of novel enzymes for lignocellulose bioconversion. Xylanases with varying specificities are commonly used to valorise the hemicellulose arabinoxylan (AX), yet characterization of specific arabinoxylanases remain limited. Two homologous GH5_34 arabinoxylanases, HhXyn5A and CtXyn5A, in which the two domains are connected by a 40-residue linker, exhibit distinct activity on AX, yielding different reaction product patterns, despite high sequence identity, conserved active sites and similar domain composition. In this study, the carbohydrate binding module 6 (CBM6), or the inter domain linker together with CBM6, were swapped to investigate their influence on hydrolytic activity and oligosaccharide product pattern on cereal AXs. The variants, with only CBM6 swapped, displayed reduced activity on commercial wheat and rye AX, as well as on extracted oat fibre, compared to the original enzymes. Additionally, exchange of both linker and CBM6 resulted in a reduced ratio of enzyme produced in soluble form in Escherichia coli cultivations, causing loss of activity of both HhXyn5A and CtXyn5A variants. Analysis of oligosaccharide product patterns applying HPAEC-PAD revealed a decreased number of reaction products for CtXyn5A with swapped CBM6, which resembled the product pattern of HhXyn5A. These findings emphasize the importance of the CBM6 interactions with the linker and the catalytic domain for enzyme activity and specificity, and underlines the role of the linker in enzyme structure organisation and product formation, where alterations in linker interactions with the catalytic and/or CBM6 domains, influence enzyme-substrate association and specificity.
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Affiliation(s)
- Siri Norlander
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Andrius Jasilionis
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Leila Allahgholi
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Christina Wennerberg
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Carl Grey
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Patrick Adlercreutz
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
| | - Eva Nordberg Karlsson
- Division of Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund SE-221 00, Sweden
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4
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Mei X, Liu G, Chen G, Zhang Y, Xue C, Chang Y. Characterization and structural identification of a family 16 carbohydrate-binding module (CBM): First structural insights into porphyran-binding CBM. Int J Biol Macromol 2024; 265:131041. [PMID: 38518929 DOI: 10.1016/j.ijbiomac.2024.131041] [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: 01/09/2024] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
Porphyran is a favorable functional polysaccharide widely distributed in Porphyra. It displays a linear structure majorly constituted by alternating 1,4-linked α-l-galactopyranose-6-sulfate (L6S) and 1,3-linked β-d-galactopyranose (G) units. Carbohydrate-binding modules (CBMs) are desired tools for the investigation and application of polysaccharides, including in situ visualization, on site and specific assay, and functionalization of biomaterials. However, only one porphyran-binding CBM has been hitherto reported, and its structural knowledge is lacking. Herein, a novel CBM16 family domain from a marine bacterium Aquimarina sp. BL5 was discovered and expressed. The recombinant protein AmCBM16 exhibited the desired specificity for porphyran. Bio-layer interferometry assay revealed that the protein binds to porphyran tetrasaccharide (L6S-G)2 with an association constant of 1.3 × 103 M-1. The structure of AmCBM16 was resolved by the X-ray crystallography, which displays a β-sandwich fold with two antiparallel β-sheets constituted by 10 β-strands. Site-directed mutagenesis analysis demonstrated that the residues Gly-30, Trp-31, Lys-88, Lys-123, Phe-125, and Phe-127 play dominant roles in AmCBM16 binding. This study provides the first structural insights into porphyran-binding CBM.
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Affiliation(s)
- Xuanwei Mei
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Guanchen Liu
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Guangning Chen
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Yuying Zhang
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Yaoguang Chang
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
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5
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Lu Z, Rämgård C, Ergenlioğlu İ, Sandin L, Hammar H, Andersson H, King K, Inman AR, Hao M, Bulone V, McKee LS. Multiple enzymatic approaches to hydrolysis of fungal β-glucans by the soil bacterium Chitinophaga pinensis. FEBS J 2023. [PMID: 36610032 DOI: 10.1111/febs.16720] [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: 08/29/2022] [Revised: 10/26/2022] [Accepted: 01/05/2023] [Indexed: 01/09/2023]
Abstract
The genome of the soil Bacteroidota Chitinophaga pinensis encodes a large number of glycoside hydrolases (GHs) with noteworthy features and potentially novel functions. Several are predicted to be active on polysaccharide components of fungal and oomycete cell walls, such as chitin, β-1,3-glucan and β-1,6-glucan. While several fungal β-1,6-glucanase enzymes are known, relatively few bacterial examples have been characterised to date. We have previously demonstrated that C. pinensis shows strong growth using β-1,6-glucan as the sole carbon source, with the efficient release of oligosaccharides from the polymer. We here characterise the capacity of the C. pinensis secretome to hydrolyse the β-1,6-glucan pustulan and describe three distinct enzymes encoded by its genome, all of which show different levels of β-1,6-glucanase activity and which are classified into different GH families. Our data show that C. pinensis has multiple tools to deconstruct pustulan, allowing the species' broad utility of this substrate, with potential implications for bacterial biocontrol of pathogens via cell wall disruption. Oligosaccharides derived from fungal β-1,6-glucans are valuable in biomedical research and drug synthesis, and these enzymes could be useful tools for releasing such molecules from microbial biomass, an underexploited source of complex carbohydrates.
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Affiliation(s)
- Zijia Lu
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Carl Rämgård
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - İrem Ergenlioğlu
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Lova Sandin
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Hugo Hammar
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Helena Andersson
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Katharine King
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Annie R Inman
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Mengshu Hao
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Vincent Bulone
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden.,College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia
| | - Lauren S McKee
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden.,Wallenberg Wood Science Centre, Stockholm, Sweden
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6
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Tseng YH, Scholz SS, Fliegmann J, Krüger T, Gandhi A, Furch ACU, Kniemeyer O, Brakhage AA, Oelmüller R. CORK1, A LRR-Malectin Receptor Kinase, Is Required for Cellooligomer-Induced Responses in Arabidopsis thaliana. Cells 2022; 11:cells11192960. [PMID: 36230919 PMCID: PMC9563578 DOI: 10.3390/cells11192960] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/16/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
Cell wall integrity (CWI) maintenance is central for plant cells. Mechanical and chemical distortions, pH changes, and breakdown products of cell wall polysaccharides activate plasma membrane-localized receptors and induce appropriate downstream responses. Microbial interactions alter or destroy the structure of the plant cell wall, connecting CWI maintenance to immune responses. Cellulose is the major polysaccharide in the primary and secondary cell wall. Its breakdown generates short-chain cellooligomers that induce Ca2+-dependent CWI responses. We show that these responses require the malectin domain-containing CELLOOLIGOMER-RECEPTOR KINASE 1 (CORK1) in Arabidopsis and are preferentially activated by cellotriose (CT). CORK1 is required for cellooligomer-induced cytoplasmic Ca2+ elevation, reactive oxygen species (ROS) production, mitogen-associated protein kinase (MAPK) activation, cellulose synthase phosphorylation, and the regulation of CWI-related genes, including those involved in biosynthesis of cell wall material, secondary metabolites and tryptophan. Phosphoproteome analyses identified early targets involved in signaling, cellulose synthesis, the endoplasmic reticulum/Golgi secretory pathway, cell wall repair and immune responses. Two conserved phenylalanine residues in the malectin domain are crucial for CORK1 function. We propose that CORK1 is required for CWI and immune responses activated by cellulose breakdown products.
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Affiliation(s)
- Yu-Heng Tseng
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | - Sandra S. Scholz
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | - Judith Fliegmann
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, 72074 Tübingen, Germany
| | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), 07745 Jena, Germany
| | - Akanksha Gandhi
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | - Alexandra C. U. Furch
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), 07745 Jena, Germany
- Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, 07743 Jena, Germany
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), 07745 Jena, Germany
| | - Ralf Oelmüller
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Department of Plant Physiology, Friedrich-Schiller-University Jena, 07743 Jena, Germany
- Correspondence:
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7
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Salmeán AA, Willats WGT, Ribeiro S, Andersen TJ, Ellegaard M. Over 100-Year Preservation and Temporal Fluctuations of Cell Wall Polysaccharides in Marine Sediments. FRONTIERS IN PLANT SCIENCE 2022; 13:785902. [PMID: 35519816 PMCID: PMC9062592 DOI: 10.3389/fpls.2022.785902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/28/2022] [Indexed: 05/16/2023]
Abstract
Polysaccharides constitute an important carbon pool in marine systems, but much is still unknown about the fate and degradation of these compounds. They are derived partly from production in situ, and in coastal areas, they are partly terrestrially derived, originating from freshwater runoff from land. The aim of this study was to test the applicability of high-throughput polysaccharide profiling for plant and algal cell-wall compounds in dated sediment cores from a coastal marine environment, to examine the preservation of cell-wall polysaccharides and explore their potential as proxies for temporal environmental changes. Preserved compounds and remains of organisms are routinely used as paleoenvironmental proxies as the amount and composition of different compounds that can provide insight into past environmental conditions, and novel means for reporting environmental changes are highly sought.
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Affiliation(s)
- Armando A. Salmeán
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- Department of Technology, University College Copenhagen, Copenhagen, Denmark
| | - William George Tycho Willats
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sofia Ribeiro
- Geological Survey of Denmark and Greenland, Copenhagen, Denmark
| | - Thorbjørn Joest Andersen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Marianne Ellegaard
- Department of Technology, University College Copenhagen, Copenhagen, Denmark
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8
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Krska D, Mazurkewich S, Brown HA, Theibich Y, Poulsen JCN, Morris AL, Koropatkin NM, Lo Leggio L, Larsbrink J. Structural and Functional Analysis of a Multimodular Hyperthermostable Xylanase-Glucuronoyl Esterase from Caldicellulosiruptor kristjansonii. Biochemistry 2021; 60:2206-2220. [PMID: 34180241 PMCID: PMC8280721 DOI: 10.1021/acs.biochem.1c00305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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The hyperthermophilic bacterium Caldicellulosiruptor kristjansonii encodes an unusual enzyme, CkXyn10C-GE15A, which
incorporates two catalytic domains, a xylanase and a glucuronoyl esterase,
and five carbohydrate-binding modules (CBMs) from families 9 and 22.
The xylanase and glucuronoyl esterase catalytic domains were recently
biochemically characterized, as was the ability of the individual
CBMs to bind insoluble polysaccharides. Here, we further probed the
abilities of the different CBMs from CkXyn10C-GE15A
to bind to soluble poly- and oligosaccharides using affinity gel electrophoresis,
isothermal titration calorimetry, and differential scanning fluorimetry.
The results revealed additional binding properties of the proteins
compared to the former studies on insoluble polysaccharides. Collectively,
the results show that all five CBMs have their own distinct binding
preferences and appear to complement each other and the catalytic
domains in targeting complex cell wall polysaccharides. Additionally,
through renewed efforts, we have achieved partial structural characterization
of this complex multidomain protein. We have determined the structures
of the third CBM9 domain (CBM9.3) and the glucuronoyl esterase (GE15A)
by X-ray crystallography. CBM9.3 is the second CBM9 structure determined
to date and was shown to bind oligosaccharide ligands at the same
site but in a different binding mode compared to that of the previously
determined CBM9 structure from Thermotoga maritima. GE15A represents a unique intermediate between reported fungal
and bacterial glucuronoyl esterase structures as it lacks two inserted
loop regions typical of bacterial enzymes and a third loop has an
atypical structure. We also report small-angle X-ray scattering measurements
of the N-terminal CBM22.1–CBM22.2–Xyn10C construct,
indicating a compact arrangement at room temperature.
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Affiliation(s)
- Daniel Krska
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Scott Mazurkewich
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.,Wallenberg Wood Science Center, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Haley A Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Yusuf Theibich
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | | | - Adeline L Morris
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Johan Larsbrink
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.,Wallenberg Wood Science Center, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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9
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Nance ML, Labonte JW, Adolf-Bryfogle J, Gray JJ. Development and Evaluation of GlycanDock: A Protein-Glycoligand Docking Refinement Algorithm in Rosetta. J Phys Chem B 2021; 125:10.1021/acs.jpcb.1c00910. [PMID: 34133179 PMCID: PMC8742512 DOI: 10.1021/acs.jpcb.1c00910] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Carbohydrate chains are ubiquitous in the complex molecular processes of life. These highly diverse chains are recognized by a variety of protein receptors, enabling glycans to regulate many biological functions. High-resolution structures of protein-glycoligand complexes reveal the atomic details necessary to understand this level of molecular recognition and inform application-focused scientific and engineering pursuits. When experimental challenges hinder high-throughput determination of quality structures, computational tools can, in principle, fill the gap. In this work, we introduce GlycanDock, a residue-centric protein-glycoligand docking refinement algorithm developed within the Rosetta macromolecular modeling and design software suite. We performed a benchmark docking assessment using a set of 109 experimentally determined protein-glycoligand complexes as well as 62 unbound protein structures. The GlycanDock algorithm can sample and discriminate among protein-glycoligand models of native-like structural accuracy with statistical reliability from starting structures of up to 7 Å root-mean-square deviation in the glycoligand ring atoms. We show that GlycanDock-refined models qualitatively replicated the known binding specificity of a bacterial carbohydrate-binding module. Finally, we present a protein-glycoligand docking pipeline for generating putative protein-glycoligand complexes when only the glycoligand sequence and unbound protein structure are known. In combination with other carbohydrate modeling tools, the GlycanDock docking refinement algorithm will accelerate research in the glycosciences.
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Affiliation(s)
- Morgan L. Nance
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jason W. Labonte
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Chemistry, Franklin & Marshall College, Lancaster, Pennsylvania 17603, United States
- Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania 17325, United States
| | - Jared Adolf-Bryfogle
- Protein Design Lab, Institute for Protein Innovation, Boston, Massachusetts 02115, United States
- Division of Hematology/Oncology, Boston Children’s Hospital, Boston, Massachusetts 02115, United States
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Jeffrey J. Gray
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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10
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Jia X, Wang C, Du X, Peng H, Liu L, Xiao Y, He C. Specific hydrolysis of curdlan with a novel glycoside hydrolase family 128 β-1,3-endoglucanase containing a carbohydrate-binding module. Carbohydr Polym 2021; 253:117276. [DOI: 10.1016/j.carbpol.2020.117276] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/30/2020] [Accepted: 10/16/2020] [Indexed: 01/07/2023]
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11
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Tamura K, Dejean G, Van Petegem F, Brumer H. Distinct protein architectures mediate species-specific beta-glucan binding and metabolism in the human gut microbiota. J Biol Chem 2021; 296:100415. [PMID: 33587952 PMCID: PMC7974029 DOI: 10.1016/j.jbc.2021.100415] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/02/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
Complex glycans that evade our digestive system are major nutrients that feed the human gut microbiota (HGM). The prevalence of Bacteroidetes in the HGM of populations worldwide is engendered by the evolution of polysaccharide utilization loci (PULs), which encode concerted protein systems to utilize the myriad complex glycans in our diets. Despite their crucial roles in glycan recognition and transport, cell-surface glycan-binding proteins (SGBPs) remained understudied cogs in the PUL machinery. Here, we report the structural and biochemical characterization of a suite of SGBP-A and SGBP-B structures from three syntenic β(1,3)-glucan utilization loci (1,3GULs) from Bacteroides thetaiotaomicron (Bt), Bacteroides uniformis (Bu), and B. fluxus (Bf), which have varying specificities for distinct β-glucans. Ligand complexes provide definitive insight into β(1,3)-glucan selectivity in the HGM, including structural features enabling dual β(1,3)-glucan/mixed-linkage β(1,3)/β(1,4)-glucan-binding capability in some orthologs. The tertiary structural conservation of SusD-like SGBPs-A is juxtaposed with the diverse architectures and binding modes of the SGBPs-B. Specifically, the structures of the trimodular BtSGBP-B and BuSGBP-B revealed a tandem repeat of carbohydrate-binding module-like domains connected by long linkers. In contrast, BfSGBP-B comprises a bimodular architecture with a distinct β-barrel domain at the C terminus that bears a shallow binding canyon. The molecular insights obtained here contribute to our fundamental understanding of HGM function, which in turn may inform tailored microbial intervention therapies.
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Affiliation(s)
- Kazune Tamura
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada; Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Guillaume Dejean
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada; Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
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12
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Significance of a family-6 carbohydrate-binding module in a modular feruloyl esterase for removing ferulic acid from insoluble wheat arabinoxylan. Enzyme Microb Technol 2020; 138:109546. [DOI: 10.1016/j.enzmictec.2020.109546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/23/2020] [Accepted: 03/03/2020] [Indexed: 11/21/2022]
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13
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Structural and Functional Studies of a Klebsiella Phage Capsule Depolymerase Tailspike: Mechanistic Insights into Capsular Degradation. Structure 2020; 28:613-624.e4. [PMID: 32386574 DOI: 10.1016/j.str.2020.04.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 04/17/2020] [Indexed: 01/01/2023]
Abstract
Capsule polysaccharide is a major virulence factor of Klebsiella pneumoniae, a nosocomial pathogen associated with a wide range of infections. It protects bacteria from harsh environmental conditions, immune system response, and phage infection. To access cell wall-located receptors, some phages possess tailspike depolymerases that degrade the capsular polysaccharide. Here, we present the crystal structure of a tailspike against Klebsiella, KP32gp38, whose primary sequence shares no similarity to other proteins of known structure. In the trimeric structure of KP32gp38, each chain contains a flexible N-terminal domain, a right-handed parallel β helix domain and two β sandwiches with carbohydrate binding features. The crystal structure and activity assays allowed us to locate the catalytic site. Also, our data provide experimental evidence of a branching architecture of depolymerases in KP32 Klebsiella viruses, as KP32gp38 displays nanomolar affinity to another depolymerase from the same phage, KP32gp37. Results provide a structural framework for enzyme engineering to produce serotype-broad-active enzyme complexes against K. pneumoniae.
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14
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Leth ML, Ejby M, Madland E, Kitaoku Y, Slotboom DJ, Guskov A, Aachmann FL, Abou Hachem M. Molecular insight into a new low‐affinity xylan binding module from the xylanolytic gut symbiont
Roseburia intestinalis. FEBS J 2019; 287:2105-2117. [DOI: 10.1111/febs.15117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/09/2019] [Accepted: 10/29/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Maria Louise Leth
- Department of Biotechnology and Biomedicine Technical University of Denmark Lyngby Denmark
| | - Morten Ejby
- Department of Biotechnology and Biomedicine Technical University of Denmark Lyngby Denmark
| | - Eva Madland
- NOBIPOL Department of Biotechnology and Food Science NTNU Norwegian University of Science and Technology Trondheim Norway
| | - Yoshihito Kitaoku
- NOBIPOL Department of Biotechnology and Food Science NTNU Norwegian University of Science and Technology Trondheim Norway
| | - Dirk J. Slotboom
- Membrane Enzymology Institute for Biomolecular Sciences & Biotechnology University of Groningen Groningen The Netherlands
| | - Albert Guskov
- Membrane Enzymology Institute for Biomolecular Sciences & Biotechnology University of Groningen Groningen The Netherlands
| | - Finn Lillelund Aachmann
- NOBIPOL Department of Biotechnology and Food Science NTNU Norwegian University of Science and Technology Trondheim Norway
| | - Maher Abou Hachem
- Department of Biotechnology and Biomedicine Technical University of Denmark Lyngby Denmark
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15
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Wang R, Xu D. Molecular dynamics investigations of oligosaccharides recognized by family 16 and 22 carbohydrate binding modules. Phys Chem Chem Phys 2019; 21:21485-21496. [PMID: 31535114 DOI: 10.1039/c9cp04673a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
As a non-catalytic domain, carbohydrate binding modules (CBMs) are often considered to play some key roles in the degradation and recognition of polysaccharides catalyzed by cellulases. In this work, we investigated the recognition dynamics of cello- or xylo-saccharides by two typical CBMs (CBM16-1 and CBM22-2), which are grouped into Type B CBMs. By combining extensive molecular dynamics, principle component analysis, and binding free energy calculations, we constructed several complex models of the two CBMs in both complex cello- and xylo-oligosaccharides. The corresponding substrate recognition affinity and critical residues having significant contributions were systematically investigated. The residues containing aromatic side chain groups were shown to contribute significantly to substrate binding. The calculated binding free energies were in fairly good agreement with the experimental measurements with the absolute mean error of 0.69 kcal mol-1. The overall electrostatic interactions were shown to have negative effects on substrate recognition. Further metadynamics simulations revealed the substrate dissociation process.
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Affiliation(s)
- Ruihan Wang
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, P. R. China.
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, P. R. China. and Research Center for Materials Genome Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China
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16
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Renevey A, Riniker S. Benchmarking Hybrid Atomistic/Coarse-Grained Schemes for Proteins with an Atomistic Water Layer. J Phys Chem B 2019; 123:3033-3042. [DOI: 10.1021/acs.jpcb.8b12149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Annick Renevey
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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Jones DR, Thomas D, Alger N, Ghavidel A, Inglis GD, Abbott DW. SACCHARIS: an automated pipeline to streamline discovery of carbohydrate active enzyme activities within polyspecific families and de novo sequence datasets. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:27. [PMID: 29441125 PMCID: PMC5798181 DOI: 10.1186/s13068-018-1027-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/18/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Deposition of new genetic sequences in online databases is expanding at an unprecedented rate. As a result, sequence identification continues to outpace functional characterization of carbohydrate active enzymes (CAZymes). In this paradigm, the discovery of enzymes with novel functions is often hindered by high volumes of uncharacterized sequences particularly when the enzyme sequence belongs to a family that exhibits diverse functional specificities (i.e., polyspecificity). Therefore, to direct sequence-based discovery and characterization of new enzyme activities we have developed an automated in silico pipeline entitled: Sequence Analysis and Clustering of CarboHydrate Active enzymes for Rapid Informed prediction of Specificity (SACCHARIS). This pipeline streamlines the selection of uncharacterized sequences for discovery of new CAZyme or CBM specificity from families currently maintained on the CAZy website or within user-defined datasets. RESULTS SACCHARIS was used to generate a phylogenetic tree of a GH43, a CAZyme family with defined subfamily designations. This analysis confirmed that large datasets can be organized into sequence clusters of manageable sizes that possess related functions. Seeding this tree with a GH43 sequence from Bacteroides dorei DSM 17855 (BdGH43b, revealed it partitioned as a single sequence within the tree. This pattern was consistent with it possessing a unique enzyme activity for GH43 as BdGH43b is the first described α-glucanase described for this family. The capacity of SACCHARIS to extract and cluster characterized carbohydrate binding module sequences was demonstrated using family 6 CBMs (i.e., CBM6s). This CBM family displays a polyspecific ligand binding profile and contains many structurally determined members. Using SACCHARIS to identify a cluster of divergent sequences, a CBM6 sequence from a unique clade was demonstrated to bind yeast mannan, which represents the first description of an α-mannan binding CBM. Additionally, we have performed a CAZome analysis of an in-house sequenced bacterial genome and a comparative analysis of B. thetaiotaomicron VPI-5482 and B. thetaiotaomicron 7330, to demonstrate that SACCHARIS can generate "CAZome fingerprints", which differentiate between the saccharolytic potential of two related strains in silico. CONCLUSIONS Establishing sequence-function and sequence-structure relationships in polyspecific CAZyme families are promising approaches for streamlining enzyme discovery. SACCHARIS facilitates this process by embedding CAZyme and CBM family trees generated from biochemically to structurally characterized sequences, with protein sequences that have unknown functions. In addition, these trees can be integrated with user-defined datasets (e.g., genomics, metagenomics, and transcriptomics) to inform experimental characterization of new CAZymes or CBMs not currently curated, and for researchers to compare differential sequence patterns between entire CAZomes. In this light, SACCHARIS provides an in silico tool that can be tailored for enzyme bioprospecting in datasets of increasing complexity and for diverse applications in glycobiotechnology.
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Affiliation(s)
- Darryl R. Jones
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
| | - Dallas Thomas
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
| | - Nicholas Alger
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
| | - Ata Ghavidel
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
| | - G. Douglas Inglis
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
| | - D. Wade Abbott
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB T1J 4B1 Canada
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18
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Furusawa G, Lau NS, Suganthi A, Amirul AAA. Agarolytic bacterium Persicobacter sp. CCB-QB2 exhibited a diauxic growth involving galactose utilization pathway. Microbiologyopen 2016; 6. [PMID: 27987272 PMCID: PMC5300873 DOI: 10.1002/mbo3.405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 08/26/2016] [Accepted: 08/29/2016] [Indexed: 11/18/2022] Open
Abstract
The agarolytic bacterium Persicobacter sp. CCB‐QB2 was isolated from seaweed (genus Ulva) collected from a coastal area of Malaysia. Here, we report a high‐quality draft genome sequence for QB2. The Rapid Annotation using Subsystem Technology (RAST) annotation server identified four β‐agarases (PdAgaA, PdAgaB, PdAgaC, and PdAgaD) as well as galK, galE, and phosphoglucomutase, which are related to the Leloir pathway. Interestingly, QB2 exhibited a diauxic growth in the presence of two kinds of nutrients, such as tryptone and agar. In cells grown with agar, the profiles of agarase activity and growth rate were very similar. galK, galE, and phosphoglucomutase genes were highly expressed in the second growth phase of diauxic growth, indicating that QB2 cells use galactose hydrolyzed from agar by its agarases and exhibit nutrient prioritization. This is the first report describing diauxic growth for agarolytic bacteria. QB2 is a potential novel model organism for studying diauxic growth in environmental bacteria.
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Affiliation(s)
- Go Furusawa
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Malaysia
| | - Nyok-Sean Lau
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Malaysia
| | - Appalasamy Suganthi
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Malaysia.,Faculty of Earth Science, Universiti Malaysia Kelantan, Jeli, Malaysia
| | - Abdullah Al-Ashraf Amirul
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Malaysia.,School of Biological Sciences, Universiti Sains Malaysia, Minden, Malaysia
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19
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Jam M, Ficko-Blean E, Labourel A, Larocque R, Czjzek M, Michel G. Unraveling the multivalent binding of a marine family 6 carbohydrate-binding module with its native laminarin ligand. FEBS J 2016; 283:1863-79. [DOI: 10.1111/febs.13707] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 02/12/2016] [Accepted: 03/07/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Murielle Jam
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
| | - Elizabeth Ficko-Blean
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
| | - Aurore Labourel
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
| | - Robert Larocque
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
| | - Mirjam Czjzek
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
| | - Gurvan Michel
- Sorbonne Université; UPMC Univ Paris 06, CNRS, UMR 8227; Integrative Biology of Marine Models; Station Biologique de Roscoff; Roscoff Cedex Bretagne France
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20
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Identification of a novel family of carbohydrate-binding modules with broad ligand specificity. Sci Rep 2016; 6:19392. [PMID: 26765840 PMCID: PMC4725902 DOI: 10.1038/srep19392] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 11/03/2015] [Indexed: 11/13/2022] Open
Abstract
Most enzymes that act on carbohydrates include non-catalytic carbohydrate-binding modules (CBMs) that recognize and target carbohydrates. CBMs bring their appended catalytic modules into close proximity with the target substrate and increase the hydrolytic rate of enzymes acting on insoluble substrates. We previously identified a novel CBM (CBMC5614-1) at the C-terminus of endoglucanase C5614-1 from an uncultured microorganism present in buffalo rumen. In the present study, that the functional region of CBMC5614-1 involved in ligand binding was localized to 134 amino acids. Two representative homologs of CBMC5614-1, sharing the same ligand binding profile, targeted a range of β-linked polysaccharides that adopt very different conformations. Targeted substrates included soluble and insoluble cellulose, β-1,3/1,4-mixed linked glucans, xylan, and mannan. Mutagenesis revealed that three conserved aromatic residues (Trp-380, Tyr-411, and Trp-423) play an important role in ligand recognition and targeting. These results suggest that CBMC5614-1 and its homologs form a novel CBM family (CBM72) with a broad ligand-binding specificity. CBM72 members can provide new insight into CBM-ligand interactions and may have potential in protein engineering and biocatalysis.
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21
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Metatranscriptomic analyses of plant cell wall polysaccharide degradation by microorganisms in the cow rumen. Appl Environ Microbiol 2016; 81:1375-86. [PMID: 25501482 DOI: 10.1128/aem.03682-14] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bovine rumen represents a highly specialized bioreactor where plant cell wall polysaccharides (PCWPs) are efficiently deconstructed via numerous enzymes produced by resident microorganisms. Although a large number of fibrolytic genes from rumen microorganisms have been identified, it remains unclear how they are expressed in a coordinated manner to efficiently degrade PCWPs. In this study, we performed a metatranscriptomic analysis of the rumen microbiomes of adult Holstein cows fed a fiber diet and obtained a total of 1,107,083 high-quality non-rRNA reads with an average length of 483 nucleotides. Transcripts encoding glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) accounted for 1% and 0.1% of the total non-rRNAs, respectively. The majority (98%) of the putative cellulases belonged to four GH families (i.e., GH5, GH9, GH45, and GH48) and were primarily synthesized by Ruminococcus and Fibrobacter. Notably, transcripts for GH48 cellobiohydrolases were relatively abundant compared to the abundance of transcripts for other cellulases. Two-thirds of the putative hemicellulases were of the GH10, GH11, and GH26 types and were produced by members of the genera Ruminococcus, Prevotella, and Fibrobacter. Most (82%) predicted oligosaccharide-degrading enzymes were GH1, GH2, GH3, and GH43 proteins and were from a diverse group of microorganisms. Transcripts for CBM10 and dockerin, key components of the cellulosome, were also relatively abundant. Our results provide metatranscriptomic evidence in support of the notion that members of the genera Ruminococcus, Fibrobacter, and Prevotella are predominant PCWP degraders and point to the significant contribution of GH48 cellobiohydrolases and cellulosome-like structures to efficient PCWP degradation in the cow rumen.
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Molecular engineering of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040: structural determinants for the reaction product size and reactivity. Biochem J 2015; 467:259-70. [PMID: 25649478 DOI: 10.1042/bj20140860] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cycloisomaltooligosaccharide glucanotransferase (CITase) is a member of glycoside hydrolase family 66 and it produces cycloisomaltooligosaccharides (CIs). Small CIs (CI-7-9) and large CIs (CI-≥10) are designated as oligosaccharide-type CIs (oligo-CIs) and megalosaccharide-type CIs (megalo-CIs) respectively. CITase from Bacillus circulans T-3040 (BcCITase) produces mainly CI-8 with little megalo-CIs. It has two family 35 carbohydrate-binding modules (BcCBM35-1 and BcCBM35-2). BcCBM35-1 is inserted in a catalytic domain of BcCITase and BcCBM35-2 is located at the C-terminal region. Our previous studies suggested that BcCBM35-1 has two substrate-binding sites (B-1 and B-2) [Suzuki et al. (2014) J. Biol. Chem. 289, 12040-12051]. We implemented site-directed mutagenesis of BcCITase to explore the preference for product size on the basis of the 3D structure of BcCITase. Mutational studies provided evidence that B-1 and B-2 contribute to recruiting substrate and maintaining product size respectively. A mutant (mutant-R) with four mutations (F268V, D469Y, A513V and Y515S) produced three times as much megalo-CIs (CI-10-12) and 1.5 times as much total CIs (CI-7-12) as compared with the wild-type (WT) BcCITase. The 3D structure of the substrate-enzyme complex of mutant-R suggested that the modified product size specificity was attributable to the construction of novel substrate-binding sites in the B-2 site of BcCBM35-1 and reactivity was improved by mutation on subsite -3 on the catalytic domain.
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Verma AK, Bule P, Ribeiro T, Brás JLA, Mukherjee J, Gupta MN, Fontes CMGA, Goyal A. The family 6 Carbohydrate Binding Module (CtCBM6) of glucuronoxylanase (CtXynGH30) of Clostridium thermocellum binds decorated and undecorated xylans through cleft A. Arch Biochem Biophys 2015; 575:8-21. [PMID: 25857803 DOI: 10.1016/j.abb.2015.03.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 02/24/2015] [Accepted: 03/17/2015] [Indexed: 10/23/2022]
Abstract
CtCBM6 of glucuronoxylan-xylanohydrolase (CtXynGH30) from Clostridium thermocellum was cloned, expressed and purified as a soluble ~14 kDa protein. Quantitative binding analysis with soluble polysaccharides by affinity electrophoresis and ITC revealed that CtCBM6 displays similar affinity towards decorated and undecorated xylans by binding wheat- and rye-arabinoxylans, beechwood-, birchwood- and oatspelt-xylan. Protein melting studies confirmed thermostable nature of CtCBM6 and that Ca(2+) ions did not affect its structure stability and binding affinity significantly. The CtCBM6 structure was modeled and refined and CD spectrum displayed 44% β-strands supporting the predicted structure. CtCBM6 displays a jelly roll β-sandwich fold presenting two potential carbohydrate binding clefts, A and B. The cleft A, is located between two loops connecting β4-β5 and β8-β9 strands. Tyr28 and Phe84 present on these loops make a planar hydrophobic binding surface to accommodate sugar ring of ligand. The cleft B, is located on concave surface of β-sandwich fold. Tyr34 and Tyr104 make a planar hydrophobic platform, which may be inaccessible to ligand due to hindrance by Pro68. Site-directed mutagenesis revealed Tyr28 and Phe84 in cleft A, playing a major role in ligand binding. The results suggest that CtCBM6 interacts with carbohydrates through cleft A, which recognizes equally well both decorated and un-decorated xylans.
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Affiliation(s)
- Anil Kumar Verma
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Pedro Bule
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Teresa Ribeiro
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Joana L A Brás
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Joyeeta Mukherjee
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Munishwar N Gupta
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Carlos M G A Fontes
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Arun Goyal
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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Xu C, Wang BC, Yu Z, Sun M. Structural insights into Bacillus thuringiensis Cry, Cyt and parasporin toxins. Toxins (Basel) 2014; 6:2732-70. [PMID: 25229189 PMCID: PMC4179158 DOI: 10.3390/toxins6092732] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/26/2014] [Accepted: 08/28/2014] [Indexed: 11/30/2022] Open
Abstract
Since the first X-ray structure of Cry3Aa was revealed in 1991, numerous structures of B. thuringiensis toxins have been determined and published. In recent years, functional studies on the mode of action and resistance mechanism have been proposed, which notably promoted the developments of biological insecticides and insect-resistant transgenic crops. With the exploration of known pore-forming toxins (PFTs) structures, similarities between PFTs and B. thuringiensis toxins have provided great insights into receptor binding interactions and conformational changes from water-soluble to membrane pore-forming state of B. thuringiensis toxins. This review mainly focuses on the latest discoveries of the toxin working mechanism, with the emphasis on structural related progress. Based on the structural features, B. thuringiensis Cry, Cyt and parasporin toxins could be divided into three categories: three-domain type α-PFTs, Cyt toxin type β-PFTs and aerolysin type β-PFTs. Structures from each group are elucidated and discussed in relation to the latest data, respectively.
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Affiliation(s)
- Chengchen Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Bi-Cheng Wang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - Ziniu Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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25
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Zhao H, Yang Y, von Itzstein M, Zhou Y. Carbohydrate-binding protein identification by coupling structural similarity searching with binding affinity prediction. J Comput Chem 2014; 35:2177-83. [PMID: 25220682 DOI: 10.1002/jcc.23730] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/27/2014] [Accepted: 08/25/2014] [Indexed: 02/03/2023]
Abstract
Carbohydrate-binding proteins (CBPs) are potential biomarkers and drug targets. However, the interactions between carbohydrates and proteins are challenging to study experimentally and computationally because of their low binding affinity, high flexibility, and the lack of a linear sequence in carbohydrates as exists in RNA, DNA, and proteins. Here, we describe a structure-based function-prediction technique called SPOT-Struc that identifies carbohydrate-recognizing proteins and their binding amino acid residues by structural alignment program SPalign and binding affinity scoring according to a knowledge-based statistical potential based on the distance-scaled finite-ideal gas reference state (DFIRE). The leave-one-out cross-validation of the method on 113 carbohydrate-binding domains and 3442 noncarbohydrate binding proteins yields a Matthews correlation coefficient of 0.56 for SPalign alone and 0.63 for SPOT-Struc (SPalign + binding affinity scoring) for CBP prediction. SPOT-Struc is a technique with high positive predictive value (79% correct predictions in all positive CBP predictions) with a reasonable sensitivity (52% positive predictions in all CBPs). The sensitivity of the method was changed slightly when applied to 31 APO (unbound) structures found in the protein databank (14/31 for APO versus 15/31 for HOLO). The result of SPOT-Struc will not change significantly if highly homologous templates were used. SPOT-Struc predicted 19 out of 2076 structural genome targets as CBPs. In particular, one uncharacterized protein in Bacillus subtilis (1oq1A) was matched to galectin-9 from Mus musculus. Thus, SPOT-Struc is useful for uncovering novel carbohydrate-binding proteins. SPOT-Struc is available at http://sparks-lab.org.
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Affiliation(s)
- Huiying Zhao
- Indiana University School of Informatics, Indiana University Purdue University, Indianapolis, 719 Indiana Ave, Suite 319, Indianapolis, Indiana, 46202; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, 46202
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26
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Abbott DW, van Bueren AL. Using structure to inform carbohydrate binding module function. Curr Opin Struct Biol 2014; 28:32-40. [PMID: 25108190 DOI: 10.1016/j.sbi.2014.07.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/24/2014] [Accepted: 07/16/2014] [Indexed: 10/24/2022]
Abstract
Generally, non-catalytic carbohydrate binding module (CBM) specificity has been shown to parallel the catalytic activity of the carbohydrate active enzyme (CAZyme) module it is appended to. With the rapid expansion in metagenomic sequence space for the potential discovery of new CBMs in addition to the recent emergence of several new CBM families that display diverse binding profiles and novel functions, elucidating the function of these protein modules has become a much more challenging task. This review summarizes several approaches that have been reported for using primary structure to inform CBM specificity and streamlining their biophysical characterization. In addition we discuss general trends in binding site architecture and several newly identified functions for CBMs. Streams of investigation that will facilitate the development and refinement of sequence-based prediction tools are suggested.
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Affiliation(s)
- D Wade Abbott
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403-1st Ave, Lethbridge, AB, Canada T1J4B1.
| | - Alicia Lammerts van Bueren
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747AG, The Netherlands
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27
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Mori T, Kamei I, Hirai H, Kondo R. Identification of novel glycosyl hydrolases with cellulolytic activity against crystalline cellulose from metagenomic libraries constructed from bacterial enrichment cultures. SPRINGERPLUS 2014; 3:365. [PMID: 25077068 PMCID: PMC4112031 DOI: 10.1186/2193-1801-3-365] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/08/2014] [Indexed: 11/11/2022]
Abstract
To obtain cellulases that are capable of degrading crystalline cellulose and cedar wood, metagenomic libraries were constructed from raw soil sample which was covered to pile of cedar wood sawdust or from its enrichment cultures. The efficiency of screening of metagenomic library was improved more than 3 times by repeating enrichment cultivation using crystalline cellulose as a carbon source, compared with the library constructed from raw soil. Four cellulase genes were obtained from the metagenomic libraries that were constructed from the total genome extracted from an enrichment culture that used crystalline cellulose as a carbon source. A cellulase gene and a xylanase gene were obtained from the enrichment culture that used unbleached kraft pulp as a carbon source. The culture supernatants of Escherichia coli expressing three clones that were derived from the enrichment culture that used crystalline cellulose showed activity against crystalline cellulose. In addition, these three enzyme solutions generated a reducing sugar from cedar wood powder. From these results, the construction of a metagenomic library from cultures that were repetition enriched using crystalline cellulose demonstrated that this technique is a powerful tool for obtaining cellulases that have activity toward crystalline cellulose.
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Affiliation(s)
- Toshio Mori
- />Department of Agro-environmental Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | - Ichiro Kamei
- />Department of Forest and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192 Japan
| | - Hirofumi Hirai
- />Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, 422-8529 Japan
| | - Ryuichiro Kondo
- />Department of Agro-environmental Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
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28
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Suzuki N, Fujimoto Z, Kim YM, Momma M, Kishine N, Suzuki R, Suzuki S, Kitamura S, Kobayashi M, Kimura A, Funane K. Structural elucidation of the cyclization mechanism of α-1,6-glucan by Bacillus circulans T-3040 cycloisomaltooligosaccharide glucanotransferase. J Biol Chem 2014; 289:12040-12051. [PMID: 24616103 DOI: 10.1074/jbc.m114.547992] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacillus circulans T-3040 cycloisomaltooligosaccharide glucanotransferase belongs to the glycoside hydrolase family 66 and catalyzes an intramolecular transglucosylation reaction that produces cycloisomaltooligosaccharides from dextran. The crystal structure of the core fragment from Ser-39 to Met-738 of B. circulans T-3040 cycloisomaltooligosaccharide glucanotransferase, devoid of its N-terminal signal peptide and C-terminal nonconserved regions, was determined. The structural model contained one catalytic (β/α)8-barrel domain and three β-domains. Domain N with an immunoglobulin-like β-sandwich fold was attached to the N terminus; domain C with a Greek key β-sandwich fold was located at the C terminus, and a carbohydrate-binding module family 35 (CBM35) β-jellyroll domain B was inserted between the 7th β-strand and the 7th α-helix of the catalytic domain A. The structures of the inactive catalytic nucleophile mutant enzyme complexed with isomaltohexaose, isomaltoheptaose, isomaltooctaose, and cycloisomaltooctaose revealed that the ligands bound in the catalytic cleft and the sugar-binding site of CBM35. Of these, isomaltooctaose bound in the catalytic site extended to the second sugar-binding site of CBM35, which acted as subsite -8, representing the enzyme·substrate complex when the enzyme produces cycloisomaltooctaose. The isomaltoheptaose and cycloisomaltooctaose bound in the catalytic cleft with a circular structure around Met-310, representing the enzyme·product complex. These structures collectively indicated that CBM35 functions in determining the size of the product, causing the predominant production of cycloisomaltooctaose by the enzyme. The canonical sugar-binding site of CBM35 bound the mid-part of isomaltooligosaccharides, indicating that the original function involved substrate binding required for efficient catalysis.
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Affiliation(s)
- Nobuhiro Suzuki
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602
| | - Zui Fujimoto
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602.
| | - Young-Min Kim
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602; Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589
| | - Mitsuru Momma
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602
| | - Naomi Kishine
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602
| | - Ryuichiro Suzuki
- Applied Microbiology Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba 305-8642
| | - Shiho Suzuki
- College of Life, Environment, and Advanced Sciences, Osaka Prefecture University, Sakai 599-8531
| | - Shinichi Kitamura
- College of Life, Environment, and Advanced Sciences, Osaka Prefecture University, Sakai 599-8531
| | - Mikihiko Kobayashi
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602; Applied Microbiology Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba 305-8642; Department of Food and Health Science, Jissen Women's University, Hino 191-8510, Japan
| | - Atsuo Kimura
- Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589
| | - Kazumi Funane
- Applied Microbiology Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba 305-8642.
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Ahmed S, Luís AS, Brás JLA, Fontes CMGA, Goyal A. Functional and structural characterization of family 6 carbohydrate-binding module (CtCBM6A) of Clostridium thermocellum α-L-arabinofuranosidase. BIOCHEMISTRY (MOSCOW) 2013; 78:1272-9. [DOI: 10.1134/s0006297913110072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Gilbert HJ, Knox JP, Boraston AB. Advances in understanding the molecular basis of plant cell wall polysaccharide recognition by carbohydrate-binding modules. Curr Opin Struct Biol 2013; 23:669-77. [DOI: 10.1016/j.sbi.2013.05.005] [Citation(s) in RCA: 236] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 05/03/2013] [Accepted: 05/09/2013] [Indexed: 11/25/2022]
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31
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Ahmed S, Luis AS, Brás JLA, Fontes CMGA, Goyal A. The family 6 carbohydrate-binding module (CtCBM6B) ofClostridium thermocellumalpha-L-arabinofuranosidase binds xylans and thermally stabilized by Ca2+ions. BIOCATAL BIOTRANSFOR 2013. [DOI: 10.3109/10242422.2013.828047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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32
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von Schantz L, Håkansson M, Logan DT, Walse B, Österlin J, Nordberg-Karlsson E, Ohlin M. Structural basis for carbohydrate-binding specificity—A comparative assessment of two engineered carbohydrate-binding modules. Glycobiology 2012; 22:948-61. [DOI: 10.1093/glycob/cws063] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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33
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Hydrophilic aromatic residue and in silico structure for carbohydrate binding module. PLoS One 2011; 6:e24814. [PMID: 21966371 PMCID: PMC3178555 DOI: 10.1371/journal.pone.0024814] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 08/18/2011] [Indexed: 01/13/2023] Open
Abstract
Carbohydrate binding modules (CBMs) are found in polysaccharide-targeting enzymes and increase catalytic efficiency. Because only a relatively small number of CBM structures have been solved, computational modeling represents an alternative approach in conjunction with experimental assessment of CBM functionality and ligand-binding properties. An accurate target-template sequence alignment is the crucial step during homology modeling. However, low sequence identities between target/template sequences can be a major bottleneck. We therefore incorporated the predicted hydrophilic aromatic residues (HARs) and secondary structure elements into our feature-incorporated alignment (FIA) algorithm to increase CBM alignment accuracy. An alignment performance comparison for FIA and six others was made, and the greatest average sequence identities and similarities were achieved by FIA. In addition, structure models were built for 817 representative CBMs. Our models possessed the smallest average surface-potential z scores. Besides, a large true positive value for liagnd-binding aromatic residue prediction was obtained by HAR identification. Finally, the pre-simulated CBM structures have been deposited in the Database of Simulated CBM structures (DS-CBMs). The web service is publicly available at http://dscbm.life.nthu.edu.tw/ and http://dscbm.cs.ntou.edu.tw/.
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34
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Hehemann JH, Marsters C, Boraston AB. Ab initio
phasing of a nucleoside hydrolase-related hypothetical protein from Saccharophagus degradans
that is associated with carbohydrate metabolism. Proteins 2011; 79:2992-8. [DOI: 10.1002/prot.23126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 05/27/2011] [Accepted: 06/03/2011] [Indexed: 11/06/2022]
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35
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Correia MAS, Mazumder K, Brás JLA, Firbank SJ, Zhu Y, Lewis RJ, York WS, Fontes CMGA, Gilbert HJ. Structure and function of an arabinoxylan-specific xylanase. J Biol Chem 2011; 286:22510-20. [PMID: 21378160 DOI: 10.1074/jbc.m110.217315] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzymatic degradation of plant cell walls plays a central role in the carbon cycle and is of increasing environmental and industrial significance. The enzymes that catalyze this process include xylanases that degrade xylan, a β-1,4-xylose polymer that is decorated with various sugars. Although xylanases efficiently hydrolyze unsubstituted xylans, these enzymes are unable to access highly decorated forms of the polysaccharide, such as arabinoxylans that contain arabinofuranose decorations. Here, we show that a Clostridium thermocellum enzyme, designated CtXyl5A, hydrolyzes arabinoxylans but does not attack unsubstituted xylans. Analysis of the reaction products generated by CtXyl5A showed that all the oligosaccharides contain an O3 arabinose linked to the reducing end xylose. The crystal structure of the catalytic module (CtGH5) of CtXyl5A, appended to a family 6 noncatalytic carbohydrate-binding module (CtCBM6), showed that CtGH5 displays a canonical (α/β)(8)-barrel fold with the substrate binding cleft running along the surface of the protein. The catalytic apparatus is housed in the center of the cleft. Adjacent to the -1 subsite is a pocket that could accommodate an l-arabinofuranose-linked α-1,3 to the active site xylose, which is likely to function as a key specificity determinant. CtCBM6, which adopts a β-sandwich fold, recognizes the termini of xylo- and gluco-configured oligosaccharides, consistent with the pocket topology displayed by the ligand-binding site. In contrast to typical modular glycoside hydrolases, there is an extensive hydrophobic interface between CtGH5 and CtCBM6, and thus the two modules cannot function as independent entities.
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Affiliation(s)
- Márcia A S Correia
- Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
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36
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Alderwick LJ, Lloyd GS, Ghadbane H, May JW, Bhatt A, Eggeling L, Fütterer K, Besra GS. The C-terminal domain of the Arabinosyltransferase Mycobacterium tuberculosis EmbC is a lectin-like carbohydrate binding module. PLoS Pathog 2011; 7:e1001299. [PMID: 21383969 PMCID: PMC3044687 DOI: 10.1371/journal.ppat.1001299] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 01/19/2011] [Indexed: 11/19/2022] Open
Abstract
The d-arabinan-containing polymers arabinogalactan (AG) and lipoarabinomannan (LAM) are essential components of the unique cell envelope of the pathogen Mycobacterium tuberculosis. Biosynthesis of AG and LAM involves a series of membrane-embedded arabinofuranosyl (Araf) transferases whose structures are largely uncharacterised, despite the fact that several of them are pharmacological targets of ethambutol, a frontline drug in tuberculosis therapy. Herein, we present the crystal structure of the C-terminal hydrophilic domain of the ethambutol-sensitive Araf transferase M. tuberculosis EmbC, which is essential for LAM synthesis. The structure of the C-terminal domain of EmbC (EmbCCT) encompasses two sub-domains of different folds, of which subdomain II shows distinct similarity to lectin-like carbohydrate-binding modules (CBM). Co-crystallisation with a cell wall-derived di-arabinoside acceptor analogue and structural comparison with ligand-bound CBMs suggest that EmbCCT contains two separate carbohydrate binding sites, associated with subdomains I and II, respectively. Single-residue substitution of conserved tryptophan residues (Trp868, Trp985) at these respective sites inhibited EmbC-catalysed extension of LAM. The same substitutions differentially abrogated binding of di- and penta-arabinofuranoside acceptor analogues to EmbCCT, linking the loss of activity to compromised acceptor substrate binding, indicating the presence of two separate carbohydrate binding sites, and demonstrating that subdomain II indeed functions as a carbohydrate-binding module. This work provides the first step towards unravelling the structure and function of a GT-C-type glycosyltransferase that is essential in M. tuberculosis. Tuberculosis (TB), an infectious disease caused by the bacillus Mycobacterium tuberculosis, burdens large swaths of the world population. Treatment of active TB typically requires administration of an antibiotic cocktail over several months that includes the drug ethambutol. This front line compound inhibits a set of arabinosyltransferase enzymes, called EmbA, EmbB and EmbC, which are critical for the synthesis of arabinan, a vital polysaccharide in the pathogen's unique cell envelope. How precisely ethambutol inhibits arabinosyltransferase activity is not clear, in part because structural information of its pharmacological targets has been elusive. Here, we report the high-resolution structure of the C-terminal domain of the ethambutol-target EmbC, a 390-amino acid fragment responsible for acceptor substrate recognition. Combining the X-ray crystallographic analysis with structural comparisons, site-directed mutagenesis, activity and ligand binding assays, we identified two regions in the C-terminal domain of EmbC that are capable of binding acceptor substrate mimics and are critical for activity of the full-length enzyme. Our results begin to define structure-function relationships in a family of structurally uncharacterised membrane-embedded glycosyltransferases, which are an important target for tuberculosis therapy.
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Affiliation(s)
- Luke J. Alderwick
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Georgina S. Lloyd
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Hemza Ghadbane
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - John W. May
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Apoorva Bhatt
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Lothar Eggeling
- Institut für Biotechnologie I, Forschungszentrum Jülich, Jülich, Germany
| | - Klaus Fütterer
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (KF); (GSB)
| | - Gurdyal S. Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (KF); (GSB)
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37
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Yoshida S, Hespen CW, Beverly RL, Mackie RI, Cann IKO. Domain analysis of a modular alpha-L-Arabinofuranosidase with a unique carbohydrate binding strategy from the fiber-degrading bacterium Fibrobacter succinogenes S85. J Bacteriol 2010; 192:5424-36. [PMID: 20709893 PMCID: PMC2950500 DOI: 10.1128/jb.00503-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 08/03/2010] [Indexed: 11/20/2022] Open
Abstract
Family 43 glycoside hydrolases (GH43s) are known to exhibit various activities involved in hemicellulose hydrolysis. Thus, these enzymes contribute to efficient plant cell wall degradation, a topic of much interest for biofuel production. In this study, we characterized a unique GH43 protein from Fibrobacter succinogenes S85. The recombinant protein showed α-l-arabinofuranosidase activity, specifically with arabinoxylan. The enzyme is, therefore, an arabinoxylan arabinofuranohydrolase (AXH). The F. succinogenes AXH (FSUAXH1) is a modular protein that is composed of a signal peptide, a GH43 catalytic module, a unique β-sandwich module (XX domain), a family 6 carbohydrate-binding module (CBM6), and F. succinogenes-specific paralogous module 1 (FPm-1). Truncational analysis and site-directed mutagenesis of the protein revealed that the GH43 domain/XX domain constitute a new form of carbohydrate-binding module and that residue Y484 in the XX domain is essential for binding to arabinoxylan, although protein structural analyses may be required to confirm some of the observations. Kinetic studies demonstrated that the Y484A mutation leads to a higher k(cat) for a truncated derivative of FSUAXH1 composed of only the GH43 catalytic module and the XX domain. However, an increase in the K(m) for arabinoxylan led to a 3-fold decrease in catalytic efficiency. Based on the knowledge that most XX domains are found only in GH43 proteins, the evolutionary relationships within the GH43 family were investigated. These analyses showed that in GH43 members with a XX domain, the two modules have coevolved and that the length of a loop within the XX domain may serve as an important determinant of substrate specificity.
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Affiliation(s)
- Shosuke Yoshida
- Energy Biosciences Institute, Institute for Genomic Biology, Department of Biochemistry, Department of Microbiology, Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801
| | - Charles W. Hespen
- Energy Biosciences Institute, Institute for Genomic Biology, Department of Biochemistry, Department of Microbiology, Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801
| | - Robert L. Beverly
- Energy Biosciences Institute, Institute for Genomic Biology, Department of Biochemistry, Department of Microbiology, Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801
| | - Roderick I. Mackie
- Energy Biosciences Institute, Institute for Genomic Biology, Department of Biochemistry, Department of Microbiology, Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801
| | - Isaac K. O. Cann
- Energy Biosciences Institute, Institute for Genomic Biology, Department of Biochemistry, Department of Microbiology, Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801
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38
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Najmudin S, Pinheiro BA, Prates JAM, Gilbert HJ, Romão MJ, Fontes CMGA. Putting an N-terminal end to the Clostridium thermocellum xylanase Xyn10B story: crystal structure of the CBM22-1-GH10 modules complexed with xylohexaose. J Struct Biol 2010; 172:353-62. [PMID: 20682344 DOI: 10.1016/j.jsb.2010.07.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/26/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
Abstract
In general, plant cell wall degrading enzymes are modular proteins containing catalytic domains linked to one or more non-catalytic carbohydrate-binding modules (CBMs). Xyn10B from Clostridium thermocellum is a typical modular enzyme containing an N-terminal family 22 CBM (CBM22-1), a family 10 glycoside hydrolase catalytic domain (GH10), a second CBM22 (CBM22-2), a dockerin sequence and a C-terminal family 1 carbohydrate esterase (CE1) catalytic domain. The structure of the N-terminal bi-modular CBM22-1-GH10 component of Xyn10B has been determined using a SeMet derivative by SAD to 2.5Å. The data was extended to 2.0Å for the non-SeMet mutant complexed with xylohexaose. CBM22-1-GH10 is a 60kDa protein with an E337A mutation to render the GH10 subunit inactive. Three of the six xylose residues of xylohexaose are shown to be bound in the inactivated GH10 substrate binding cleft, with the other three sugars presumably disordered in the solvent channel. The protein is a dimer in the asymmetric unit with extensive surface contacts between the two GH10 modules and between the CBM22-1 and GH10 modules. Residues from helix H4 of the GH10 module provide the major contacts by fitting into the minor groove of the CBM22-1 module. The orientation of CBM22-1 is such that it would allow the substrate to be loosely bound and subsequently delivered to the active site in a processive manner.
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Affiliation(s)
- Shabir Najmudin
- CIISA - Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal.
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39
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Ribeiro T, Santos-Silva T, Alves VD, Dias FMV, Luís AS, Prates JAM, Ferreira LMA, Romão MJ, Fontes CMGA. Family 42 carbohydrate-binding modules display multiple arabinoxylan-binding interfaces presenting different ligand affinities. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:2054-62. [PMID: 20637315 DOI: 10.1016/j.bbapap.2010.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/29/2010] [Accepted: 07/03/2010] [Indexed: 11/16/2022]
Abstract
Enzymes that degrade plant cell wall polysaccharides display a modular architecture comprising a catalytic domain bound to one or more non-catalytic carbohydrate-binding modules (CBMs). CBMs display considerable variation in primary structure and are grouped into 59 sequence-based families organized in the Carbohydrate-Active enZYme (CAZy) database. Here we report the crystal structure of CtCBM42A together with the biochemical characterization of two other members of family 42 CBMs from Clostridium thermocellum. CtCBM42A, CtCBM42B and CtCBM42C bind specifically to the arabinose side-chains of arabinoxylans and arabinan, suggesting that various cellulosomal components are targeted to these regions of the plant cell wall. The structure of CtCBM42A displays a beta-trefoil fold, which comprises 3 sub-domains designated as alpha, beta and gamma. Each one of the three sub-domains presents a putative carbohydrate-binding pocket where an aspartate residue located in a central position dominates ligand recognition. Intriguingly, the gamma sub-domain of CtCBM42A is pivotal for arabinoxylan binding, while the concerted action of beta and gamma sub-domains of CtCBM42B and CtCBM42C is apparently required for ligand sequestration. Thus, this work reveals that the binding mechanism of CBM42 members is in contrast with that of homologous CBM13s where recognition of complex polysaccharides results from the cooperative action of three protein sub-domains presenting similar affinities.
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Affiliation(s)
- Teresa Ribeiro
- CIISA-Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
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40
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Requirement of the type II secretion system for utilization of cellulosic substrates by Cellvibrio japonicus. Appl Environ Microbiol 2010; 76:5079-87. [PMID: 20543053 DOI: 10.1128/aem.00454-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cellulosic biofuels represent a powerful alternative to petroleum but are currently limited by the inefficiencies of the conversion process. While gram-positive and fungal organisms have been widely explored as sources of cellulases and hemicellulases for biomass degradation, gram-negative organisms have received less experimental attention. We investigated the ability of Cellvibrio japonicus, a recently sequenced gram-negative cellulolytic bacterium, to degrade bioenergy-related feedstocks. Using a newly developed biomass medium, we showed that C. japonicus is able to utilize corn stover and switchgrass as sole sources of carbon and energy for growth. We also developed tools for directed gene disruptions in C. japonicus and used this system to construct a mutant in the gspD gene, which is predicted to encode a component of the type II secretion system. The gspD::pJGG1 mutant displayed a greater-than-2-fold decrease in endoglucanase secretion compared to wild-type C. japonicus. In addition, the mutant strain showed a pronounced growth defect in medium with biomass as a carbon source, yielding 100-fold fewer viable cells than the wild type. To test the potential of C. japonicus to undergo metabolic engineering, we constructed a strain able to produce small amounts of ethanol from biomass. Collectively, these data suggest that C. japonicus is a useful platform for biomass conversion and biofuel production.
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Gilbert HJ. The biochemistry and structural biology of plant cell wall deconstruction. PLANT PHYSIOLOGY 2010; 153:444-55. [PMID: 20406913 PMCID: PMC2879781 DOI: 10.1104/pp.110.156646] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 04/17/2010] [Indexed: 05/18/2023]
Affiliation(s)
- Harry J Gilbert
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
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Schallus T, Fehér K, Sternberg U, Rybin V, Muhle-Goll C. Analysis of the specific interactions between the lectin domain of malectin and diglucosides. Glycobiology 2010; 20:1010-20. [DOI: 10.1093/glycob/cwq059] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Biochemical and domain analyses of FSUAxe6B, a modular acetyl xylan esterase, identify a unique carbohydrate binding module in Fibrobacter succinogenes S85. J Bacteriol 2009; 192:483-93. [PMID: 19897648 DOI: 10.1128/jb.00935-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acetyl xylan esterase (EC 3.1.1.72) is a member of a set of enzymes required to depolymerize hemicellulose, especially xylan that is composed of a main chain of beta-1,4-linked xylopyranoside residues decorated with acetyl side groups. Fibrobacter succinogenes S85 Axe6B (FSUAxe6B) is an acetyl xylan esterase encoded in the genome of this rumen bacterium. The enzyme is a modular protein comprised of an esterase domain, a carbohydrate-binding module, and a region of unknown function. Sequences that are homologous to the region of unknown function are paralogously distributed, thus far, only in F. succinogenes. Therefore, the sequences were designated Fibrobacter succinogenes-specific paralogous module 1 (FPm-1). The FPm-1s are associated with at least 24 polypeptides in the genome of F. succinogenes S85. A bioinformatics search showed that most of the FPm-1-appended polypeptides are putative carbohydrate-active enzymes, suggesting a potential role in carbohydrate metabolism. Truncational analysis of FSUAxe6B, together with catalytic and substrate binding studies, has allowed us to delineate the functional modules in the polypeptide. The N-terminal half of FSUAxe6B harbors the activity that cleaves side chain acetyl groups from xylan-like substrates, and the binding of insoluble xylan was determined to originate from FPm-1. Site-directed mutagenesis studies of highly conserved active-site residues in the esterase domain suggested that the esterase activity is derived from a tetrad composed of Ser(44), His(273), Glu(194), and Asp(270), with both Glu(194) and Asp(270) functioning as helper acids, instead of a single carboxylate residue proposed to initiate catalysis.
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Abbott DW, Ficko-Blean E, van Bueren AL, Rogowski A, Cartmell A, Coutinho PM, Henrissat B, Gilbert HJ, Boraston AB. Analysis of the Structural and Functional Diversity of Plant Cell Wall Specific Family 6 Carbohydrate Binding Modules. Biochemistry 2009; 48:10395-404. [DOI: 10.1021/bi9013424] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Wade Abbott
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 STN CSC, Victoria, British Columbia V8W 3P6, Canada
| | - Elizabeth Ficko-Blean
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 STN CSC, Victoria, British Columbia V8W 3P6, Canada
| | - Alicia Lammerts van Bueren
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 STN CSC, Victoria, British Columbia V8W 3P6, Canada
| | - Artur Rogowski
- School of Biomedical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, U.K
| | - Alan Cartmell
- School of Biomedical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, U.K
| | - Pedro M. Coutinho
- Laboratoire d’Architecture et de Fonction des macromolécules Biologiques, IBSM, CNRS Marseille and University Aix-Marseille I & II, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Bernard Henrissat
- Laboratoire d’Architecture et de Fonction des macromolécules Biologiques, IBSM, CNRS Marseille and University Aix-Marseille I & II, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Harry J. Gilbert
- School of Biomedical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, U.K
| | - Alisdair B. Boraston
- Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 STN CSC, Victoria, British Columbia V8W 3P6, Canada
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Ueda Y, Ohwada S, Abe Y, Shibata T, Iijima M, Yoshimitsu Y, Koshiba T, Nakata M, Ueda T, Kawabata SI. Factor G utilizes a carbohydrate-binding cleft that is conserved between horseshoe crab and bacteria for the recognition of beta-1,3-D-glucans. THE JOURNAL OF IMMUNOLOGY 2009; 183:3810-8. [PMID: 19710471 DOI: 10.4049/jimmunol.0900430] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the horseshoe crab, the recognition of beta-1,3-D-glucans by factor G triggers hemolymph coagulation. Factor G contains a domain of two tandem xylanase Z-like modules (Z1-Z2), each of which recognizes beta-1,3-D-glucans. To gain an insight into the recognition of beta-1,3-D-glucans from a structural view point, recombinants of Z1-Z2, the C-terminal module Z2, Z2 with a Cys to Ala substitution (Z2A), and its tandem repeat Z2A-Z2A were characterized. Z2 and Z1-Z2, but not Z2A and Z2A-Z2A, formed insoluble aggregates at higher concentrations more than approximately 30 and 3 microM, respectively. Z1-Z2 and Z2A-Z2A bound more strongly to an insoluble beta-1,3-D-glucan (curdlan) than Z2A. The affinity of Z2A for a soluble beta-1,3-D-glucan (laminarin) was equivalent to those of Z1-Z2, Z2A-Z2A, and native factor G, suggesting that the binding of a single xylanase Z-like module prevents the subsequent binding of another module to laminarin. Interestingly, Z2A as well as intact factor G exhibited fungal agglutinating activity, and fungi were specifically detected with fluorescently tagged Z2A by microscopy. The chemical shift perturbation of Z2A induced by the interaction with laminaripentaose was analyzed by nuclear magnetic resonance spectroscopy. The ligand-binding site of Z2A was located in a cleft on a beta-sheet in a predicted beta-sandwich structure, which was superimposed onto cleft B in a cellulose-binding module of endoglucanase 5A from the soil bacterium Cellvibrio mixtus. We conclude that the pattern recognition for beta-1,3-D-glucans by factor G is accomplished via a carbohydrate-binding cleft that is evolutionally conserved between horseshoe crab and bacteria.
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Affiliation(s)
- Yuki Ueda
- Graduate School of Systems Life Sciences, Faculty of Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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Vincent F, Round A, Reynaud A, Bordi C, Filloux A, Bourne Y. Distinct oligomeric forms of the Pseudomonas aeruginosa RetS sensor domain modulate accessibility to the ligand binding site. Environ Microbiol 2009; 12:1775-86. [DOI: 10.1111/j.1462-2920.2010.02264.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Ficko-Blean E, Boraston AB. N-acetylglucosamine recognition by a family 32 carbohydrate-binding module from Clostridium perfringens NagH. J Mol Biol 2009; 390:208-20. [PMID: 19422833 PMCID: PMC2937040 DOI: 10.1016/j.jmb.2009.04.066] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 04/24/2009] [Accepted: 04/27/2009] [Indexed: 10/20/2022]
Abstract
Many carbohydrate-active enzymes have complex architectures comprising multiple modules that may be involved in catalysis, carbohydrate binding, or protein-protein interactions. Carbohydrate-binding modules (CBMs) are a common ancillary module whose function is to promote the adherence of the complete enzyme to carbohydrate substrates. CBM family 32 has been proposed to be one of the most diverse CBM families classified to date, yet all of the structurally characterized CBM32s thus far recognize galactose-based ligands. Here, we report a unique binding specificity and mode of ligand binding for a family 32 CBM. NagHCBM32-2 is one of four CBM32 modules in NagH, a family 84 glycoside hydrolase secreted by Clostridium perfringens. NagHCBM32-2 has the beta-sandwich scaffold common to members of the family; however, its specificity for N-acetylglucosamine is unusual among CBMs. X-ray crystallographic analysis of the module at resolutions from 1.45 to 2.0 A and in complex with disaccharides reveals that its mode of sugar recognition is quite different from that observed for galactose-specific CBM32s. This study continues to unravel the diversity of CBMs found in family 32 and how these CBMs might impart the carbohydrate-binding specificity to the extracellular glycoside hydrolases in C. perfringens.
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Affiliation(s)
- Elizabeth Ficko-Blean
- Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
| | - Alisdair B. Boraston
- Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
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Michel G, Barbeyron T, Kloareg B, Czjzek M. The family 6 carbohydrate-binding modules have coevolved with their appended catalytic modules toward similar substrate specificity. Glycobiology 2009; 19:615-23. [PMID: 19240276 DOI: 10.1093/glycob/cwp028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The survey of carbohydrate active enzymes in genomic data uncovered the modular architecture of most of these proteins. Many of the additional modules associated with catalytic modules tightly bind carbohydrates. The primary role of these carbohydrate-binding modules (CBMs) is to enhance the enzymatic activity of the ensemble by bringing their appended catalytic module(s) in intimate contact with their substrates. Biochemical and biophysical approaches have unraveled the subtle interplay of the modules and the structural basis for their ligand specificities, but little attention has been paid to the evolutionary mechanisms leading to the appearance of modular architecture in carbohydrate active enzymes. Focusing on the promiscuous family CBM6 modules, we investigated the evolution of substrate specificities in parallel to that of their respectively appended catalytic modules. An extensive phylogenetic analysis of family CBM6 modules indicates that these noncatalytic modules have diverged into clades which coincide with their substrate selectivity. These data as well as the remarkable congruence of the phylogenetic trees inferred from CBM6s on the one hand and their associated catalytic modules on the other hand show that CBM6s and their associated glycoside hydrolases have coevolved to acquire the same substrate specificity. We also propose an evolutionary scenario explaining the emergence of the modular agarases, by which existent alpha-agarases acquired their agar-binding CBM6 module through a lateral transfer from pre-existing beta-agarases. Altogether, this observed coevolution between CBM6s and their catalytic modules will facilitate the prediction of the substrate specificity of uncharacterized CBM6 modules present in genomic data.
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Affiliation(s)
- Gurvan Michel
- UPMC University Paris 06, 3CNRS, UMR 7139 Marine Plants and Biomolecules, Station Biologique de Roscoff, Roscoff, Bretagne, France.
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Structural analysis of a glycoside hydrolase family 43 arabinoxylan arabinofuranohydrolase in complex with xylotetraose reveals a different binding mechanism compared with other members of the same family. Biochem J 2009; 418:39-47. [PMID: 18980579 DOI: 10.1042/bj20081256] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AXHs (arabinoxylan arabinofuranohydrolases) are alpha-L-arabinofuranosidases that specifically hydrolyse the glycosidic bond between arabinofuranosyl substituents and xylopyranosyl backbone residues of arabinoxylan. Bacillus subtilis was recently shown to produce an AXH that cleaves arabinose units from O-2- or O-3-mono-substituted xylose residues: BsAXH-m2,3 (B. subtilis AXH-m2,3). Crystallographic analysis reveals a two-domain structure for this enzyme: a catalytic domain displaying a five-bladed beta-propeller fold characteristic of GH (glycoside hydrolase) family 43 and a CBM (carbohydrate-binding module) with a beta-sandwich fold belonging to CBM family 6. Binding of substrate to BsAXH-m2,3 is largely based on hydrophobic stacking interactions, which probably allow the positional flexibility needed to hydrolyse both arabinose substituents at the O-2 or O-3 position of the xylose unit. Superposition of the BsAXH-m2,3 structure with known structures of the GH family 43 exo-acting enzymes, beta-xylosidase and alpha-L-arabinanase, each in complex with their substrate, reveals a different orientation of the sugar backbone.
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Viegas A, Brás NF, Cerqueira NMFSA, Fernandes PA, Prates JAM, Fontes CMGA, Bruix M, Romão MJ, Carvalho AL, Ramos MJ, Macedo AL, Cabrita EJ. Molecular determinants of ligand specificity in family 11 carbohydrate binding modules - an NMR, X-ray crystallography and computational chemistry approach. FEBS J 2008; 275:2524-35. [DOI: 10.1111/j.1742-4658.2008.06401.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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