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Badruna L, Burlat V, Montanier CY. CBMs as Probes to Explore Plant Cell Wall Heterogeneity Using Immunocytochemistry. Methods Mol Biol 2023; 2657:163-179. [PMID: 37149530 DOI: 10.1007/978-1-0716-3151-5_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Immunocytochemistry is a widely used technique to localize antigen within intact tissues. Plant cell walls are complex matrixes of highly decorated polysaccharides and the large number of CBM families displaying specific substrate recognition reflects this complexity. The accessibility of large proteins, such as antibodies, to their cell wall epitopes may be sometimes difficult due to steric hindrance problems. Due to their smaller size, CBMs are interesting alternative probes. The aim of this chapter is to describe the use of CBM as probes to explore complex polysaccharide topochemistry in muro and to quantify enzymatic deconstruction.
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Affiliation(s)
- Louise Badruna
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Vincent Burlat
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UT3, INP-ENSAT, Auzeville-Tolosane, France
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2
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Sidar A, Albuquerque ED, Voshol GP, Ram AFJ, Vijgenboom E, Punt PJ. Carbohydrate Binding Modules: Diversity of Domain Architecture in Amylases and Cellulases From Filamentous Microorganisms. Front Bioeng Biotechnol 2020; 8:871. [PMID: 32850729 PMCID: PMC7410926 DOI: 10.3389/fbioe.2020.00871] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/07/2020] [Indexed: 12/11/2022] Open
Abstract
Enzymatic degradation of abundant renewable polysaccharides such as cellulose and starch is a field that has the attention of both the industrial and scientific community. Most of the polysaccharide degrading enzymes are classified into several glycoside hydrolase families. They are often organized in a modular manner which includes a catalytic domain connected to one or more carbohydrate-binding modules. The carbohydrate-binding modules (CBM) have been shown to increase the proximity of the enzyme to its substrate, especially for insoluble substrates. Therefore, these modules are considered to enhance enzymatic hydrolysis. These properties have played an important role in many biotechnological applications with the aim to improve the efficiency of polysaccharide degradation. The domain organization of glycoside hydrolases (GHs) equipped with one or more CBM does vary within organisms. This review comprehensively highlights the presence of CBM as ancillary modules and explores the diversity of GHs carrying one or more of these modules that actively act either on cellulose or starch. Special emphasis is given to the cellulase and amylase distribution within the filamentous microorganisms from the genera of Streptomyces and Aspergillus that are well known to have a great capacity for secreting a wide range of these polysaccharide degrading enzyme. The potential of the CBM and other ancillary domains for the design of improved polysaccharide decomposing enzymes is discussed.
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Affiliation(s)
- Andika Sidar
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands.,Department of Food Science and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Erica D Albuquerque
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands.,Sun Pharmaceutical Industries Europe BV., Hoofddorp, Netherlands
| | - Gerben P Voshol
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands.,Dutch DNA Biotech B.V., Utrecht, Netherlands
| | - Arthur F J Ram
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands
| | - Erik Vijgenboom
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands
| | - Peter J Punt
- Department of Microbial Biotechnology, Institute of Biology Leiden, Leiden, Netherlands.,Dutch DNA Biotech B.V., Utrecht, Netherlands
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3
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Schwarz WH, Brunecky R, Broeker J, Liebl W, Zverlov VV. Handling gene and protein names in the age of bioinformatics: the special challenge of secreted multimodular bacterial enzymes such as the cbhA/cbh9A gene of Clostridium thermocellum. World J Microbiol Biotechnol 2018; 34:42. [PMID: 29480332 DOI: 10.1007/s11274-018-2424-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 02/20/2018] [Indexed: 01/11/2023]
Abstract
An increasing number of researchers working in biology, biochemistry, biotechnology, bioengineering, bioinformatics and other related fields of science are using biological molecules. As the scientific background of the members of different scientific communities is more diverse than ever before, the number of scientists not familiar with the rules for non-ambiguous designation of genetic elements is increasing. However, with biological molecules gaining importance through biotechnology, their functional and unambiguous designation is vital. Unfortunately, naming genes and proteins is not an easy task. In addition, the traditional concepts of bioinformatics are challenged with the appearance of proteins comprising different modules with a respective function in each module. This article highlights basic rules and novel solutions in designation recently used within the community of bacterial geneticists, and we discuss the present-day handling of gene and protein designations. As an example we will utilize a recent mischaracterization of gene nomenclature. We make suggestions for better handling of names in future literature as well as in databases and annotation projects. Our methodology emphasizes the hydrolytic function of multi-modular genes and extracellular proteins from bacteria.
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Affiliation(s)
- Wolfgang H Schwarz
- Department of Microbiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil‑Ramann‑Str. 4, 85354, Freising, Germany.
| | - Roman Brunecky
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Jannis Broeker
- Department of Microbiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil‑Ramann‑Str. 4, 85354, Freising, Germany
| | - Wolfgang Liebl
- Department of Microbiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil‑Ramann‑Str. 4, 85354, Freising, Germany
| | - Vladimir V Zverlov
- Department of Microbiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil‑Ramann‑Str. 4, 85354, Freising, Germany. .,Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 2, 123182, Moscow, Russia.
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4
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Elucidating biochemical features and biological roles of Streptomyces proteins recognizing crystalline chitin- and cellulose-types and their soluble derivatives. Carbohydr Res 2017; 448:220-226. [PMID: 28712648 DOI: 10.1016/j.carres.2017.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 06/19/2017] [Indexed: 12/19/2022]
Abstract
Pioneering biochemical, immunological, physiological and microscopic studies in combination with gene cloning allowed uncovering previously unknown genes encoding proteins of streptomycetes to target crystalline chitin and cellulose as well as their soluble degradation-compounds via binding protein dependent transporters. Complementary analyses provoked an understanding of novel regulators governing transcription of selected genes. These discoveries induced detecting close and distant homologues of former orphan proteins encoded by genes from different bacteria. Grounded on structure-function-relationships, several researchers identified a few of these proteins as novel members of the growing family for lytic polysaccharides monooxygenases. Exemplary, the ecological significance of the characterized proteins including their role to promote interactions among organisms is outlined and discussed.
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5
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Badruna L, Burlat V, Montanier CY. CBMs as Probes to Explore Plant Cell Wall Heterogeneity Using Immunocytochemistry. Methods Mol Biol 2017; 1588:181-197. [PMID: 28417369 DOI: 10.1007/978-1-4939-6899-2_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Immunocytochemistry is a widely used technique to localize antigen within intact tissues. Plant cell walls are complex matrixes of highly decorated polysaccharides and the large number of CBM families displaying specific substrate recognition reflects this complexity. The accessibility of large proteins, such as antibodies, to their cell wall epitopes may be sometimes difficult due to steric hindrance problems. Due to their smaller size, CBMs are interesting alternative probes. The aim of this chapter is to describe the use of CBM as probes to explore complex polysaccharide topochemistry in muro and to quantify enzymatic deconstruction.
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Affiliation(s)
- Louise Badruna
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077, Toulouse, France
| | - Vincent Burlat
- Laboratoire de Recherche en Sciences Végétales, UMR 5546 UPS/CNRS, 31326, Castanet-Tolosan, France
| | - Cédric Y Montanier
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077, Toulouse, France.
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6
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Poulsen HV, Willink FW, Ingvorsen K. Aerobic and anaerobic cellulase production by Cellulomonas uda. Arch Microbiol 2016; 198:725-35. [PMID: 27154570 PMCID: PMC4995238 DOI: 10.1007/s00203-016-1230-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/08/2016] [Accepted: 04/25/2016] [Indexed: 10/29/2022]
Abstract
Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands.
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Affiliation(s)
- Henrik Vestergaard Poulsen
- Department of Bioscience, Section for Microbiology, Aarhus University, Ny Munkegade 116, 8000, Aarhus C, Denmark
| | - Fillip Wolfgang Willink
- Department of Bioscience, Section for Microbiology, Aarhus University, Ny Munkegade 116, 8000, Aarhus C, Denmark
| | - Kjeld Ingvorsen
- Department of Bioscience, Section for Microbiology, Aarhus University, Ny Munkegade 116, 8000, Aarhus C, Denmark.
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7
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Engineering versatile protein expression systems mediated by inteins in Escherichia coli. Appl Microbiol Biotechnol 2015; 100:255-62. [PMID: 26381664 DOI: 10.1007/s00253-015-6960-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/13/2015] [Accepted: 08/23/2015] [Indexed: 10/23/2022]
Abstract
We have recently employed an intein, Saccharomyces cerevisiae vascular membrane ATPase (VMA), in conjunction with efficient expression and secretory functions formed between the ompA leader sequence and the human epidermal growth factor (EGF) gene (fused at the 5' end of VMA), and the human basic fibroblast growth factor (bFGF) gene (fused at the 3' end of VMA), to engineer an efficient intein-based Escherichia coli system for high-level co-expression of EGF and bFGF as authentic mature products. Both products were found not only excreted to the culture medium but also located, surprisingly, in the cytoplasm (Kwong and Wong 2013). In this study, we employed two structurally varied inteins, VMA and Mycobacterium xenopi GyraseA (GyrA), and further demonstrated that despite acting alone, both VMA and GyrA were able to mediate successful co-expression of two widely different proteins, EGF and an endoglucanase (Eng) in E. coli. Although EGF and Eng were initially expressed as large precursors/intermediates, they were soluble and auto-cleavable to finally yield the desired products in both the cytoplasm and culture media. The results further substantiate our postulation that the aforementioned intein/E. coli approach might lead to the development of cost-effective and versatile host systems, wherein all culture fractions are involved in producing the target proteins.
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8
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Kognole AA, Payne CM. Cello-oligomer-binding dynamics and directionality in family 4 carbohydrate-binding modules. Glycobiology 2015; 25:1100-11. [DOI: 10.1093/glycob/cwv048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 07/04/2015] [Indexed: 12/11/2022] Open
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9
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Nakazawa H, Kim DM, Matsuyama T, Ishida N, Ikeuchi A, Ishigaki Y, Kumagai I, Umetsu M. Hybrid Nanocellulosome Design from Cellulase Modules on Nanoparticles: Synergistic Effect of Catalytically Divergent Cellulase Modules on Cellulose Degradation Activity. ACS Catal 2013. [DOI: 10.1021/cs400012v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hikaru Nakazawa
- Department of Biomolecular Engineering,
Graduate school of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Do-Myoung Kim
- Department of Biomolecular Engineering,
Graduate school of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Takashi Matsuyama
- Toyota Central R&D Laboratories, Yokomichi 41-1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480-1192, Japan
| | - Nobuhiro Ishida
- Toyota Central R&D Laboratories, Yokomichi 41-1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480-1192, Japan
| | - Akinori Ikeuchi
- Toyota Central R&D Laboratories, Yokomichi 41-1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480-1192, Japan
| | - Yuri Ishigaki
- Department of Biomolecular Engineering,
Graduate school of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Izumi Kumagai
- Department of Biomolecular Engineering,
Graduate school of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Mitsuo Umetsu
- Department of Biomolecular Engineering,
Graduate school of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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10
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Kim DM, Nakazawa H, Umetsu M, Matsuyama T, Ishida N, Ikeuchi A, Takahashi H, Asano R, Kumagai I. A nanocluster design for the construction of artificial cellulosomes. Catal Sci Technol 2012. [DOI: 10.1039/c2cy00371f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Kim DM, Umetsu M, Takai K, Matsuyama T, Ishida N, Takahashi H, Asano R, Kumagai I. Enhancement of cellulolytic enzyme activity by clustering cellulose binding domains on nanoscaffolds. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:656-64. [PMID: 21290602 DOI: 10.1002/smll.201002114] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Indexed: 05/07/2023]
Abstract
Cellulose, one of the most abundant carbon resources, is degraded by cellulolytic enzymes called cellulases. Cellulases are generally modular proteins with independent catalytic and cellulose-binding domain (CBD) modules and, in some bacteria, catalytic modules are noncovalently assembled on a scaffold protein with CBD to form a giant protein complex called a cellulosome, which efficiently degrades water-insoluble hard materials. In this study, a catalytic module and CBD are independently prepared by recombinant means, and are heterogeneously clustered on streptavidin and on inorganic nanoparticles for the construction of artificial cellulosomes. Heteroclustering of the catalytic module with CBD results in significant improvements in the enzyme's degradation activity for water-insoluble substrates. In particular, the increase of CBD valency in the cluster structure critically enhances the catalytic activity by improving the affinity for substrates, and clustering with multiple CBDs on CdSe nanoparticles generates a 7.2-fold increase in the production of reducing sugars relative to that of the native free enzyme. The multivalent design of substrate-binding domain on clustered cellulases is important for the construction of the artificial cellulosome, and the nanoparticles are an effective scaffold for increasing the valence of CBD in clustered cellulases. A new design is proposed for artificial cellulosomes with multiple CBDs on noncellulosome-derived scaffold structures.
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Affiliation(s)
- Do-Myoung Kim
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6-6-11, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
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12
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Winterhalter C, Liebl W. Two Extremely Thermostable Xylanases of the Hyperthermophilic Bacterium Thermotoga maritima MSB8. Appl Environ Microbiol 2010; 61:1810-5. [PMID: 16535021 PMCID: PMC1388439 DOI: 10.1128/aem.61.5.1810-1815.1995] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During growth with xylose or xylan as the source of carbon, xylanase production by Thermotoga maritima MSB8 was enhanced about 10-fold compared with growth with glucose or starch. Two extremely thermostable endoxylanases (1,4-(beta)-d-xylan-xylanohydrolase, EC 3.2.1.8), designated XynA and XynB, were identified and purified from cells of this organism. XynA and XynB occurred as proteins with apparent molecular masses of about 120 and 40 kDa, respectively, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Maximum activity at the optimal pH (pH 6.2 and pH 5.4 for XynA and XynB, respectively) was measured at about 92(deg)C for XynA (10-min assay) and at about 105(deg)C for XynB (5-min assay). XynB activity was stimulated twofold by the addition of 500 mM NaCl, while XynA displayed maximum activity without the addition of salt. Both xylanases were tolerant of relatively high salt concentrations. At 2 M (about 12% wt/vol) NaCl, XynA and XynB retained 49 and 65%, respectively, of their maximum activities. In contrast to XynB, XynA was able to adsorb to microcrystalline cellulose. Antibodies raised against a recombinant truncated XynA protein cross-reacted with XynB, indicating that the enzymes may have sequence or structural similarities. Part of the xylanase activity appeared to be associated with the outer membrane of T. maritima cells, since more than 40% of the total xylanase activity present in the crude cellular extract was found in the membrane fraction after high-speed centrifugation. Most of the membrane-bound activity appeared to be due to the 120-kDa xylanase XynA.
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13
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Ong E, Gilkes NR, Miller RC, Warren RA, Kilburn DG. The cellulose-binding domain (CBD(Cex)) of an exoglucanase from Cellulomonas fimi: production in Escherichia coli and characterization of the polypeptide. Biotechnol Bioeng 2010; 42:401-9. [PMID: 18613043 DOI: 10.1002/bit.260420402] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The gene fragment encoding the cellulose-binding domain (CBD) of an exoglucanase (Cex) from Cellulomonas fimi was subcloned and expressed in Escherichia coli. Transcription from the lac promoter coupled with translation from a consensus prokaryotic ribosome binding site led to the production of large quantities of CBD(Cex) (up to 25% total soluble cell protein). The polypeptide leaked into the culture supernatant (up to 50 mg . L(-1)), facilitating one-step purification by affinity chromatography on cellulose. The 11-kDa polypeptide reacted with Cex antiserum. Absence of free thiols indicated that the two Cys residues of CBD(Cex) form a disulfide bridge. It had the same N-terminal amino acid sequence as CBD(Cex) prepared from Cex by proteolysis, plus two additional N-terminal amino acid residues (Ala and Ser) encoded by the Nhel site introduced during plasmid construction. CBD(Cex) bound to a variety of beta-1, 4-glycans with different affinities and saturation levels. Adsorption to bacterial microcrystalline cellulose was dependent on the temperature, but not on the pH.
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Affiliation(s)
- E Ong
- Department of Microbiology and Protein Engineering Network of Centres of Excellence, University of British Columbia, Vancouver, British Columbia, Canada
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14
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Bach H, Gutnick DL. A unique polypeptide from the C-terminus of the exocellular esterase of Acinetobacter venetianus RAG-1 modulates the emulsifying activity of the polymeric bioemulsifier apoemulsan. Appl Microbiol Biotechnol 2005; 71:177-83. [PMID: 16237525 DOI: 10.1007/s00253-005-0161-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2005] [Revised: 08/23/2005] [Accepted: 08/31/2005] [Indexed: 10/25/2022]
Abstract
An exocellular esterase from the oil-degrading Acinetobacter venetianus RAG-1 was previously shown to enhance the emulsification and emulsion stabilization properties of the amphipathic, aminopolysaccharide bioemulsifier, emulsan [Bach H, Berdichevsky Y, Gutnick D (2003) An exocellular protein from the oil-degrading microbe Acinetobacter venetianus RAG-1 enhances the emulsifying activity of the polymeric bioemulsifier emulsan. Appl Environ Microbiol 69:2608-15]. This enhancement was specific for the RAG-1 esterase and was independent of catalytic activity. In this report, fragments from both the N'- and C'-termini were cloned as fusions to the C-terminus of the maltose-binding protein (MBP) and were tested for enhancement activity in the presence of the deproteinated form of emulsan, apoemulsan. The activity could be localized to the C-terminal third of the protein which exhibited the same activity as the intact enzyme. MBP itself was completely inactive and could be cleaved from the fusion without affecting the subsequent emulsification. However, the enhancement completely depended on the presence of a unique C-terminal 20 amino acid peptide not found in any other protein in the databases. In addition, progressive removal of amino acids from the N-terminus of the active MBP polypeptide resulted in a concomitant loss of activity, indicating that enhancement is also proportional to the size of the peptide fragment. The middle third and the C-terminal third of the enzyme each contained a copy of the conserved Cardin-Weintraub consensus sequence for protein binding to heparin. These sequences were not detected in homologous esterases from a closely related strain, Acinetobacter calcoaceticus BD413.
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Affiliation(s)
- Horacio Bach
- Division of Infectious Diseases, Vancouver General Hospital, BC, Canada
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15
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Abstract
Cellulomonas is a unique bacterium possessing not only the capacity to degrade various carbohydrates, such as starch, xylan and cellulose, but crystalline cellulose as well. It has developed a complex battery of glucanases to deal with substrates possessing such extensive microheterogeneities. Some of these enzymes are multifunctional, as well as cross inducible, possessing a multi-domain structure; these enzymes are thought to have arisen by the shuffling of these domains. Intergeneric hybrids have been constructed between Cellulomonas and Zymomonas so as to enhance the industrial potential of this organism. This review examines the unique features of this microorganism and evaluates its key role in the conversion of complex wastes to useful products, by virtue of its unusual attributes.
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Affiliation(s)
- P Chaudhary
- Molecular Biology Research Laboratory, Department of Zoology, University of Poona, Pune-411 007, India
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16
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Fusion of family VI cellulose binding domains to Bacillus halodurans xylanase increases its catalytic activity and substrate-binding capacity to insoluble xylan. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1177(02)00226-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Kwan E, Guarna MM, Boraston AB, Gilkes NR, Haynes CA, Kilburn DG, Warren RAJ. Self-activating factor X derivative fused to the C-terminus of a cellulose-binding module: Production and properties. Biotechnol Bioeng 2002; 79:724-32. [PMID: 12209795 DOI: 10.1002/bit.10312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this work, a new derivative of FX was engineered. It comprises a cellulose-binding module (CBM) fused to the N-terminus of the truncated light chain (E2FX) of FX and a hexahistidine tag (H6) fused to the C-terminus of the heavy chain. The sequence LTR at the site of cleavage of the activation peptide from the N-terminus of the heavy chain is changed to IEGR to render the derivative self-activating. However, N-linked glycans on the CBM of the derivative blocked its binding to cellulose and those on the activation peptide slowed its activation. Therefore, the sites of N-linked glycosylation on the CBM and on the activation peptide were eliminated by mutation. The final derivative can be produced in good yield by cultured mammalian cells. It is purified easily with Ni(2+)-agarose, it is self-activating, and it can be immobilized on cellulose. When immobilized on a column of cellulose beads, the activated derivative retains approximately 80% of its initial activity after 30 days of continuous hydrolysis of a fusion protein substrate. Under these conditions of operation, the effective substrate:enzyme ratio is >10(4).
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Affiliation(s)
- Emily Kwan
- Department of Microbiology and Immunology, University of British Columbia, Vancouver BC, Canada
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18
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Murashima K, Nishimura T, Nakamura Y, Koga J, Moriya T, Sumida N, Yaguchi T, Kono T. Purification and characterization of new endo-1,4-β-d-glucanases from Rhizopus oryzae. Enzyme Microb Technol 2002. [DOI: 10.1016/s0141-0229(01)00513-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Zverlov VV, Volkov IY, Velikodvorskaya GA, Schwarz WH. The binding pattern of two carbohydrate-binding modules of laminarinase Lam16A from Thermotoga neapolitana: differences in beta-glucan binding within family CBM4. MICROBIOLOGY (READING, ENGLAND) 2001; 147:621-629. [PMID: 11238969 DOI: 10.1099/00221287-147-3-621] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Carbohydrate-binding modules (CBMs) are often part of the complex hydrolytic extracellular enzymes from bacteria and may modulate their catalytic activity. The thermostable catalytic domain of laminarinase Lam16A from Thermotoga neapolitana (glycosyl hydrolase family 16) is flanked by two CBMs, 148 and 161 aa long. They share a sequence identity of 30%, are homologous to family CBM4 and are thus called CBM4-1 and CBM4-2 respectively. Recombinant Lam16A proteins deleted for one or both binding modules and the isolated module CBM4-1 were characterized. Proteins containing the N-terminal module CBM4-1 bound to the soluble polysaccharides laminarin (1,3-beta-glucan) and barley 1,3/1,4-beta-glucan, and proteins containing the C-terminal module CBM4-2 bound additionally to curdlan (1,3-beta-glucan) and pustulan (1,6-beta-glucan), and to insoluble yeast cell wall beta-glucan. The activity of the catalytic domain on soluble 1,3-beta-glucans was stimulated by the presence of CBM4-1, whereas the presence of CBM4-2 enhanced the Lam16A activity towards gelatinized and insoluble or mixed-linkage 1,3-beta-glucan. Thermostability of the catalytic domain was not affected by the truncations. Members of family CBM4 can be divided into four subfamilies, members of which show different polysaccharide-binding specificities corresponding to the catalytic specificities of the associated hydrolytic domains.
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Affiliation(s)
- Vladimir V Zverlov
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq., 123182 Moscow, Russia1
| | - Ilia Y Volkov
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq., 123182 Moscow, Russia1
| | - Galina A Velikodvorskaya
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq., 123182 Moscow, Russia1
| | - Wolfgang H Schwarz
- Research Group Microbial Biotechnology, Technische Universität München, Am Hochanger 4, D-85350 Freising-Weihenstephan, Germany2
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Kataeva IA, Seidel RD, Li XL, Ljungdahl LG. Properties and mutation analysis of the CelK cellulose-binding domain from the Clostridium thermocellum cellulosome. J Bacteriol 2001; 183:1552-9. [PMID: 11160085 PMCID: PMC95039 DOI: 10.1128/jb.183.5.1552-1559.2001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The family IV cellulose-binding domain of Clostridium thermocellum CelK (CBD(CelK)) was expressed in Escherichia coli and purified. It binds to acid-swollen cellulose (ASC) and bacterial microcrystalline cellulose (BMCC) with capacities of 16.03 and 3.95 micromol/g of cellulose and relative affinities (K(r)) of 2.33 and 9.87 liters/g, respectively. The CBD(CelK) is the first representative of family IV CBDs to exhibit an affinity for BMCC. The CBD(CelK) also binds to the soluble polysaccharides lichenin, glucomannan, and barley beta-glucan, which are substrates for CelK. It does not bind to xylan, galactomannan, and carboxymethyl cellulose. The CBD(CelK) contains 1 mol of calcium per mol. The CBD(CelK) has three thiol groups and one disulfide, reduction of which results in total loss of cellulose-binding ability. To reveal amino acid residues important for biological function of the domain and to investigate the role of calcium in the CBD(CelK) four highly conserved aromatic residues (Trp(56), Trp(94), Tyr(111), and Tyr(136)) and Asp(192) were mutated into alanines, giving the mutants W56A, W94A, Y111A, Y136A, and D192A. In addition 14 N-terminal amino acids were deleted, giving the CBD-N(CelK). The CBD-N(CelK) and D192A retained binding parameters close to that of the intact CBD(CelK), W56A and W94A totally lost the ability to bind to cellulose, Y136A bound to both ASC and BMCC but with significantly reduced binding capacity and K(r) and Y111A bound weakly to ASC and did not bind to BMCC. Mutations of the aromatic residues in the CBD(CelK) led to structural changes revealed by studying solubility, circular-dichroism spectra, dimer formation, and aggregation. Calcium content was drastically decreased in D192A. The results suggest that Asp192 is in the calcium-binding site of the CBD(CelK) and that calcium does not affect binding to cellulose. The 14 amino acids from the N terminus of the CBD(CelK) are not important for binding. Tyr136, corresponding to Cellulomonas fimi CenC CBD(N1) Y85, located near the binding cleft, might be involved in the formation of the binding surface, while Y111, W56A, and W94A are essential for the binding process by keeping the CBD(CelK) correctly folded.
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Affiliation(s)
- I A Kataeva
- Department of Biochemistry and Molecular Biology and Center for Biological Resources Recovery, The University of Georgia, Athens, Georgia 30602-7229, USA
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Henrissat B, Davies GJ. Glycoside hydrolases and glycosyltransferases. Families, modules, and implications for genomics. PLANT PHYSIOLOGY 2000; 124:1515-9. [PMID: 11115868 PMCID: PMC1539306 DOI: 10.1104/pp.124.4.1515] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- B Henrissat
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6098, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
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McLean BW, Bray MR, Boraston AB, Gilkes NR, Haynes CA, Kilburn DG. Analysis of binding of the family 2a carbohydrate-binding module from Cellulomonas fimi xylanase 10A to cellulose: specificity and identification of functionally important amino acid residues. PROTEIN ENGINEERING 2000; 13:801-9. [PMID: 11161112 DOI: 10.1093/protein/13.11.801] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The family 2a carbohydrate-binding module (CBM2a) of xylanase 10A from Cellulomonas fimi binds to the crystalline regions of cellulose. It does not share binding sites with the N-terminal family 4 binding module (CBM4-1) from the cellulase 9B from C.fimi, a module that binds strictly to soluble sugars and amorphous cellulose. The binding of CBM2a to crystalline matrices is mediated by several residues on the binding face, including three prominent, solvent-exposed tryptophan residues. Binding to crystalline cellulose was analyzed by making a series of conservative (phenylalanine and tyrosine) and non-conservative substitutions (alanine) of each solvent-exposed tryptophan (W17, W54 and W72). Other residues on the binding face with hydrogen bonding potential were substituted with alanine. Each tryptophan plays a different role in binding; a tryptophan is essential at position 54, a tyrosine or tryptophan at position 17 and any aromatic residue at position 72. Other residues on the binding face, with the exception of N15, are not essential determinants of binding affinity. Given the specificity of CBM2a, the structure of crystalline cellulose and the dynamic nature of the binding of CBM2a, we propose a model for the interaction between the polypeptide and the crystalline surface.
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Affiliation(s)
- B W McLean
- Department of Microbiology and Immunology, University of British Columbia, 300-6174 University Boulevard, Vancouver, BC, Canada V6T 1Z3
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Abstract
Chitinases frequently display a modular structure featuring a catalytic domain attached to one or several ancillary noncatalytic domains whose function is often chitin binding. Gene cloning and DNA sequencing have allowed the determination of a massive number of amino acid sequences of chitinases during the last 10 years. This chapter presents a unifying classification system of the various chitinase modules that combines specific features of their sequences, three-dimensional structures and reaction mechanisms.
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Affiliation(s)
- B Henrissat
- Architecture et Fonction des Macromolécules Biologiques CNRS, Marseille, France
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Meissner K, Wassenberg D, Liebl W. The thermostabilizing domain of the modular xylanase XynA of Thermotoga maritima represents a novel type of binding domain with affinity for soluble xylan and mixed-linkage beta-1,3/beta-1, 4-glucan. Mol Microbiol 2000; 36:898-912. [PMID: 10844677 DOI: 10.1046/j.1365-2958.2000.01909.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Thermotoga maritima XynA is an extremely thermostable modular enzyme with five domains (A1-A2-B-C1-C2). Its catalytic domain (-B-) is flanked by duplicated non-catalytic domains. The C-terminal repeated domains represent cellulose-binding domains (CBDs). Xylanase domains related to the N-terminal domains of XynA (A1-A2) are called thermostabilizing domains because their deletion normally leads to increased thermosensitivity of the enzymes. It was found that a glutathione-S-transferase (GST) hybrid protein (GST-A1A2) containing both A-domains of XynA can interact with various soluble xylan preparations and with mixed-linkage beta-1,3/beta-1,4-glucans. GST-A1A2 showed no affinity for insoluble microcrystalline cellulose, whereas, vice versa, GST-C2, which contains the C-terminal CBD of XynA, did not interact with soluble xylan. Another hybrid protein, GST-A2, displayed the same binding properties as GST-A1A2, indicating that A2 alone can also promote xylan binding. The dissociation constants for the binding of xylose, xylobiose, xylotriose, xylotetraose and xylopentaose by GST-A2, as determined at 20 degrees C by fluorescence quench experiments, were 8.1 x 10(-3) M, 2.3 x 10(-4) M, 2.3 x 10(-5) M, 2.5 x 10(-6)M and 1.1 x 10(-6) M respectively. The A-domains of XynA, which are designated as xylan binding domains (XBD), are, from the structural as well as the functional point of view, prototypes of a novel class of binding domains. More than 50 related protein segments with hitherto unknown function were detected in about 30 other multidomain beta-glycanases, among them putative plant (Arabidopsis thaliana) xylanases. It is argued that polysaccharide binding and not thermostabilization is the main function of A-like domains.
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Affiliation(s)
- K Meissner
- Institut für Mikrobiologie und Genetik, Georg-August-Universität, Göttingen, Germany
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Gaudin C, Belaich A, Champ S, Belaich JP. CelE, a multidomain cellulase from Clostridium cellulolyticum: a key enzyme in the cellulosome? J Bacteriol 2000; 182:1910-5. [PMID: 10714996 PMCID: PMC101874 DOI: 10.1128/jb.182.7.1910-1915.2000] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CelE, one of the three major proteins of the cellulosome of Clostridium cellulolyticum, was characterized. The amino acid sequence of the protein deduced from celE DNA sequence led us to the supposition that CelE is a three-domain protein. Recombinant CelE and a truncated form deleted of the putative cellulose binding domain (CBD) were obtained. Deletion of the CBD induces a total loss of activity. Exhibiting rather low levels of activity on soluble, amorphous, and crystalline celluloses, CelE is more active on p-nitrophenyl-cellobiose than the other cellulases from this organism characterized to date. The main product of its action on Avicel is cellobiose (more than 90% of the soluble sugars released), and its attack on carboxymethyl cellulose is accompanied by a relatively small decrease in viscosity. All of these features suggest that CelE is a cellobiohydrolase which has retained a certain capacity for random attack mode. We measured saccharification of Avicel and bacterial microcrystalline cellulose by associations of CelE with four other cellulases from C. cellulolyticum and found that CelE acts synergistically with all tested enzymes. The positive influence of CelE activity on the activities of other cellulosomal enzymes may explain its relative abundance in the cellulosome.
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Affiliation(s)
- C Gaudin
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM, Centre National de la Recherche Scientifique, Marseille, France.
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Simpson HD, Barras F. Functional analysis of the carbohydrate-binding domains of Erwinia chrysanthemi Cel5 (Endoglucanase Z) and an Escherichia coli putative chitinase. J Bacteriol 1999; 181:4611-6. [PMID: 10419961 PMCID: PMC103594 DOI: 10.1128/jb.181.15.4611-4616.1999] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/1999] [Accepted: 05/26/1999] [Indexed: 11/20/2022] Open
Abstract
The Cel5 cellulase (formerly known as endoglucanase Z) from Erwinia chrysanthemi is a multidomain enzyme consisting of a catalytic domain, a linker region, and a cellulose binding domain (CBD). A three-dimensional structure of the CBD(Cel5) has previously been obtained by nuclear magnetic resonance. In order to define the role of individual residues in cellulose binding, site-directed mutagenesis was performed. The role of three aromatic residues (Trp18, Trp43, and Tyr44) in cellulose binding was demonstrated. The exposed potential hydrogen bond donors, residues Gln22 and Glu27, appeared not to play a role in cellulose binding, whereas residue Asp17 was found to be important for the stability of Cel5. A deletion mutant lacking the residues Asp17 to Pro23 bound only weakly to cellulose. The sequence of CBD(Cel5) exhibits homology to a series of five repeating domains of a putative large protein, referred to as Yheb, from Escherichia coli. One of the repeating domains (Yheb1), consisting of 67 amino acids, was cloned from the E. coli chromosome and purified by metal chelating chromatography. While CBD(Cel5) bound to both cellulose and chitin, Yheb1 bound well to chitin, but only very poorly to cellulose. The Yheb protein contains a region that exhibits sequence homology with the catalytic domain of a chitinase, which is consistent with the hypothesis that the Yheb protein is a chitinase.
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Affiliation(s)
- H D Simpson
- Laboratoire de Chimie Bacterienne, Centre National de la Recherche Scientifique, 13402 Marseille Cedex 20, France
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Johnson PE, Brun E, MacKenzie LF, Withers SG, McIntosh LP. The cellulose-binding domains from Cellulomonas fimi beta-1, 4-glucanase CenC bind nitroxide spin-labeled cellooligosaccharides in multiple orientations. J Mol Biol 1999; 287:609-25. [PMID: 10092463 DOI: 10.1006/jmbi.1999.2627] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The N-terminal cellulose-binding domains CBDN1 and CBDN2 from Cellulomonas fimi cellulase CenC each adopt a jelly-roll beta-sandwich structure with a cleft into which amorphous cellulose and soluble cellooligosaccharides bind. To determine the orientation of the sugar chain within these binding clefts, the association of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl-4-yl) spin-labeled derivatives of cellotriose and cellotetraose with isolated CBDN1 and CBDN2 was studied using heteronuclear 1H-15N NMR spectroscopy. Quantitative binding measurements indicate that the TEMPO moiety does not significantly perturb the affinity of the cellooligo-saccharide derivatives for the CBDs. The paramagnetic enhancements of the amide 1HN longitudinal (DeltaR1) and transverse (DeltaR2) relaxation rates were measured by comparing the effects of TEMPO-cellotetraose in its nitroxide (oxidized) and hydroxylamine (reduced) forms on the two CBDs. The bound spin-label affects most significantly the relaxation rates of amides located at both ends of the sugar-binding cleft of each CBD. Similar results are observed with TEMPO-cellotriose bound to CBDN1. This demonstrates that the TEMPO-labeled cellooligosaccharides, and by inference strands of amorphous cellulose, can associate with CBDN1 and CBDN2 in either orientation across their beta-sheet binding clefts. The ratio of the association constants for binding in each of these two orientations is estimated to be within a factor of five to tenfold. This finding is consistent with the approximate symmetry of the hydrogen-bonding groups on both the cellooligosaccharides and the residues forming the binding clefts of the CenC CBDs.
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Affiliation(s)
- P E Johnson
- Protein Engineering Network of Centres of Excellence and Department of Chemistry and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
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Hamada N, Okumura R, Fuse N, Kodaira R, Shimosaka M, Kanda T, Okazaki M. Isolation and transcriptional analysis of a cellulase gene (cell) from the basidiomycete Irpex lacteus. J Biosci Bioeng 1999; 87:97-102. [PMID: 16232432 DOI: 10.1016/s1389-1723(99)80015-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/1998] [Accepted: 10/15/1998] [Indexed: 10/18/2022]
Abstract
A gene (named cell) homologous to the cellobiohydrolase I gene (cbhl) of Trichoderma reesei was isolated and sequenced from the white rot basidiomycete Irpex lacteus MC-2. The cell open reading frame consists of 1551 bp, which is interrupted by two introns, encoding a polypeptide of 517 amino acid residues with a calculated molecular mass of 54,522 Da. The deduced amino acid sequence showed that CEL1 (the protein encoded by cell) has a modular structure consisting of a catalytic domain of 449 amino acids and a C-terminal cellulose-binding domain (CBD) of 36 amino acids separated by a proline-, serine-, threonine-rich linker region of 32 amino acids. The CEL1 catalytic domain is homologous with fungal cellobiohydrolases (CBHs) belonging to family 7 of the glycosyl hydrolases. The transcription of cell was induced in the presence of various cellulosic substrates and repressed by glucose. It was therefore concluded that the reported sequence represents the first cellulase gene isolated from the basidiomycete Irpex.
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Affiliation(s)
- N Hamada
- Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
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Hamada N, Ishikawa K, Fuse N, Kodaira R, Shimosaka M, Amano Y, Kanda T, Okazaki M. Purification, characterization and gene analysis of exo-cellulase II (Ex-2) from the white rot basidiomycete Irpex lacteus. J Biosci Bioeng 1999; 87:442-51. [PMID: 16232497 DOI: 10.1016/s1389-1723(99)80092-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/1998] [Accepted: 12/07/1998] [Indexed: 11/23/2022]
Abstract
A new exo-type cellulase, named exo-cellulase II (Ex-2), was purified from the crude enzyme preparation of Irpex lacteus. Ex-2 was very similar to the previously characterized exo-cellulase I (Ex-1) with respect to enzymatic features such as optimal pH, temperature, heat stability, and catalytic activity. However, Ex-2 exhibited greater pH stability than Ex-1. The molecular mass and carbohydrate content of Ex-2 (56,000, 4.0%) were different from those of Ex-1 (53,000, 2.0%). A cellulase gene (named cel2) encoding both Ex-2 and Ex-1 was isolated from an I. lacteus genomic library. The cel2 gene was found to consist of 1569 bp with an open reading frame encoding 523 amino acids, interrupted by two introns. The deduced amino acid sequences revealed that cel2 ORF has a modular structure consisting of a catalytic domain and a fungal-type cellulose-binding domain (CBD) separated by a serine-rich linker region. The catalytic domain was homologous to those of fungal cellobiohydrolases belonging to family 7 of the glycosyl hydrolases. Northern blot analysis showed that expression of the cel2 gene was induced by various cellulosic substrates and repressed by glucose, fructose, and lactose.
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Affiliation(s)
- N Hamada
- Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
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Bok JD, Yernool DA, Eveleigh DE. Purification, characterization, and molecular analysis of thermostable cellulases CelA and CelB from Thermotoga neapolitana. Appl Environ Microbiol 1998; 64:4774-81. [PMID: 9835561 PMCID: PMC90921 DOI: 10.1128/aem.64.12.4774-4781.1998] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1998] [Accepted: 09/10/1998] [Indexed: 11/20/2022] Open
Abstract
Two thermostable endocellulases, CelA and CelB, were purified from Thermotoga neapolitana. CelA (molecular mass, 29 kDa; pI 4.6) is optimally active at pH 6.0 at 95 degreesC, while CelB (molecular mass, 30 kDa; pI 4.1) has a broader optimal pH range (pH 6.0 to 6.6) at 106 degreesC. Both enzymes are characterized by a high level of activity (high Vmax value and low apparent Km value) with carboxymethyl cellulose; the specific activities of CelA and CelB are 1,219 and 1,536 U/mg, respectively. With p-nitrophenyl cellobioside the Vmax values of CelA and CelB are 69.2 and 18.4 U/mg, respectively, while the Km values are 0.97 and 0.3 mM, respectively. The major end products of cellulose hydrolysis, glucose and cellobiose, competitively inhibit CelA, and CelB. The Ki values for CelA are 0.44 M for glucose and 2.5 mM for cellobiose; the Ki values for CelB are 0.2 M for glucose and 1.16 mM for cellobiose. CelB preferentially cleaves larger cellooligomers, producing cellobiose as the end product; it also exhibits significant transglycosylation activity. This enzyme is highly thermostable and has half-lives of 130 min at 106 degreesC and 26 min at 110 degreesC. A single clone encoding the celA and celB genes was identified by screening a T. neapolitana genomic library in Escherichia coli. The celA gene encodes a 257-amino-acid protein, while celB encodes a 274-amino-acid protein. Both proteins belong to family 12 of the glycosyl hydrolases, and the two proteins are 60% similar to each other. Northern blots of T. neapolitana mRNA revealed that celA and celB are monocistronic messages, and both genes are inducible by cellobiose and are repressed by glucose.
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Affiliation(s)
- J D Bok
- Department of Biochemistry and Microbiology, Cook College, Rutgers University, New Brunswick, New Jersey 08901, USA
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Tomme P, Boraston A, McLean B, Kormos J, Creagh AL, Sturch K, Gilkes NR, Haynes CA, Warren RA, Kilburn DG. Characterization and affinity applications of cellulose-binding domains. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 715:283-96. [PMID: 9792516 DOI: 10.1016/s0378-4347(98)00053-x] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cellulose-binding domains (CBDs) are discrete protein modules found in a large number of carbohydrolases and a few nonhydrolytic proteins. To date, almost 200 sequences can be classified in 13 different families with distinctly different properties. CBDs vary in size from 4 to 20 kDa and occur at different positions within the polypeptides; N-terminal, C-terminal and internal. They have a moderately high and specific affinity for insoluble or soluble cellulosics with dissociation constants in the low micromolar range. Some CBDs bind irreversibly to cellulose and can be used for applications involving immobilization, others bind reversibly and are more useful for separations and purifications. Dependent on the CBD used, desorption from the matrix can be promoted under various different conditions including denaturants (urea, high pH), water, or specific competitive ligands (e.g. cellobiose). Family I and IV CBDs bind reversibly to cellulose in contrast to family II and III CBDs which are in general, irreversibly bound. The binding of family II CBDs (CBD(Cex)) to crystalline cellulose is characterized by a large favourable increase in entropy indicating that dehydration of the sorbent and the protein are the major driving forces for binding. In contrast, binding of family IV CBDs (CBD(N1)) to amorphous or soluble cellulosics is driven by a favourable change in enthalpy which is partially offset by an unfavourable entropy change. Hydrogen bond formation and van der Waals interactions are the main driving forces for binding. CBDs with affinity for crystalline cellulose are useful tags for classical column affinity chromatography. The affinity of CBD(N1) for soluble cellulosics makes it suitable for use in large-scale aqueous two-phase affinity partitioning systems.
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Affiliation(s)
- P Tomme
- Protein Engineering Networks of Centres of Excellence, University of British Columbia, Vancouver, Canada
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Takada G, Kawaguchi T, Sumitani JI, Arai M. Cloning, nucleotide sequence, and transcriptional analysis of Aspergillus aculeatus no. F-50 cellobiohydrolase I (cbhI) gene. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0922-338x(97)80345-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Gal L, Gaudin C, Belaich A, Pages S, Tardif C, Belaich JP. CelG from Clostridium cellulolyticum: a multidomain endoglucanase acting efficiently on crystalline cellulose. J Bacteriol 1997; 179:6595-601. [PMID: 9352905 PMCID: PMC179584 DOI: 10.1128/jb.179.21.6595-6601.1997] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The gene coding for CelG, a family 9 cellulase from Clostridium cellulolyticum, was cloned and overexpressed in Escherichia coli. Four different forms of the protein were genetically engineered, purified, and studied: CelGL (the entire form of CelG), CelGcat1 (the catalytic domain of CelG alone), CelGcat2 (CelGcat1 plus 91 amino acids at the beginning of the cellulose binding domain [CBD]), and GST-CBD(CelG) (the CBD of CelG fused to glutathione S-transferase). The biochemical properties of CelG were compared with those of CelA, an endoglucanase from C. cellulolyticum which was previously studied. CelG, like CelA, was found to have an endo cutting mode of activity on carboxymethyl cellulose (CMC) but exhibited greater activity on crystalline substrates (bacterial microcrystalline cellulose and Avicel) than CelA. As observed with CelA, the presence of the nonhydrolytic miniscaffolding protein (miniCipC1) enhanced the activity of CelG on phosphoric acid swollen cellulose (PASC), but to a lesser extent. The absence of the CBD led to the complete inactivation of the enzyme. The abilities of CelG and GST-CBD(CelG) to bind various substrates were also studied. Although the entire enzyme is able to bind to crystalline cellulose at a limited number of sites, the chimeric protein GST-CBD(CelG) does not bind to either of the tested substrates (Avicel and PASC). The lack of independence between the two domains and the weak binding to cellulose suggest that this CBD-like domain may play a special role and be either directly or indirectly involved in the catalytic reaction.
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Affiliation(s)
- L Gal
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM, Centre National de la Recherche Scientifique, Marseille, France
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Nordberg Karlsson E, Bartonek-Roxå E, Holst O. Cloning and sequence of a thermostable multidomain xylanase from the bacterium Rhodothermus marinus. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1353:118-24. [PMID: 9294005 DOI: 10.1016/s0167-4781(97)00093-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The gene (xyn1) encoding a Rhodothermus marinus xylanase has been cloned and expressed in Escherichia coli. The gene comprises 5 different domains in an unusual combination. The cellulose binding domains (CBDs) encoded by xyn1 are repeated in tandem at the N-terminus and show similarity with the CBD family IV. The xyn1-gene is the first example encoding a CBD family IV in combination with a xylan hydrolyzing catalytic domain of the glycosyl hydrolase family 10.
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Affiliation(s)
- E Nordberg Karlsson
- Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Sweden.
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37
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Henriksson G, Salumets A, Divne C, Pettersson G. Studies of cellulose binding by cellobiose dehydrogenase and a comparison with cellobiohydrolase 1. Biochem J 1997; 324 ( Pt 3):833-8. [PMID: 9210407 PMCID: PMC1218499 DOI: 10.1042/bj3240833] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The binding isotherm to cellulose of cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium has been compared with that of cellobiohydrolase 1 (CBH 1) from Trichoderma reesei. CDH binds more strongly but more sparsely to cellulose than does CBH 1. In a classical Scatchard analysis, a better fit to a one-site binding model was obtained for CDH than for CBH 1. The binding of both enzymes decreased in the presence of ethylene glycol, increased in the presence of ammonium sulphate and was unaffected by sodium chloride. Attempts to localize the cellulose-binding site on CDH have also been made by exposing enzymically digested CDH to cellulose and isolating the cellulose-bound peptides. The results suggest that the cellulose-binding site is located internally in the amino acid sequence of CDH.
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Affiliation(s)
- G Henriksson
- Department of Biochemistry, University of Uppsala, Biomedical Center, Box 576, S-751 23 Uppsala, Sweden
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38
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Binding reversibility and surface exchange of Thermomonospora fusca E3 and E5 and Trichoderma reesei CBHI. Enzyme Microb Technol 1997. [DOI: 10.1016/s0141-0229(96)00178-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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39
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Zverlov VV, Volkov IY, Velikodvorskaya TV, Schwarz WH. Highly thermostable endo-1,3-beta-glucanase (laminarinase) LamA from Thermotoga neapolitana: nucleotide sequence of the gene and characterization of the recombinant gene product. MICROBIOLOGY (READING, ENGLAND) 1997; 143 ( Pt 5):1701-1708. [PMID: 9168619 DOI: 10.1099/00221287-143-5-1701] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The nucleotide sequence of clone pTT26 (3786 bp), containing the gene for 1,3-beta-glucanase LamA (laminarinase) from Thermotoga neapolitana, was determined. It contains an ORF encoding a protein of 646 aa (73328 Da). The central part of the protein is homologous to the complete catalytic domain of bacterial and some eukaryotic endo-1,3-beta-D-glucanases and belongs to family 16 of glycosyl hydrolases. This domain is flanked on both sides by one copy on each side of a substrate binding domain homologue (family II). The recombinant laminarinase protein was purified from Escherichia coli host cells in two forms, a 73 kDa and a processed 52 kDa protein, both having high specific activity towards laminarin (3100 and 2600 U mg-1, respectively) and K(m) values of 2.8 and 2.2 mg ml-1, respectively. Limited activity on 1,3-1,4-beta-glucan (lichenan) was detected (90 U mg-1). Laminarin was degraded in an endoglucanase modus, yielding glucose, laminaribiose and -triose as end products. Thus LamA classifies as an endo-1,3(4)-beta-glucanase (EC 3.2.1.6). The optimum temperature of the enzymes was 95 degrees C (73 kDa) and 85 degrees C (52 kDa) at an optimum pH of 6.2. The superior thermostability of the 73 kDa enzyme is demonstrated by incubation without substrate at 100 degrees C, where 57% of the initial activity remained after 30 min (82% at 95 degrees C). Thus, LamA is the most thermostable 1,3-beta-glucanase described to date.
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Affiliation(s)
- Vladimir V Zverlov
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 46, 123 182 Moscow, Russia
| | - Ilia Y Volkov
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 46, 123 182 Moscow, Russia
| | - Tatjana V Velikodvorskaya
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 46, 123 182 Moscow, Russia
| | - Wolfgang H Schwarz
- Institute for Microbiology, Technical University of München, Arcisstr. 21, D-80290 München, Germany
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40
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Comparison of the adsorption properties of a single-chain antibody fragment fused to a fungal or bacterial cellulose-binding domain. Enzyme Microb Technol 1997. [DOI: 10.1016/s0141-0229(96)00109-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Tomme P, Gilkes NR, Guarna MM, Haynes CA, Hasenwinkle D, Jervis E, Johnson P, McIntosh L, Warren RA, Kilburn DG. Cellulose-binding domains. Versatile affinity tags for inexpensive large-scale purification, concentration, and immobilization of fusion proteins. Ann N Y Acad Sci 1996; 799:418-24. [PMID: 8958104 DOI: 10.1111/j.1749-6632.1996.tb33235.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- P Tomme
- Biotechnology Laboratory, University of British Columbia, Vancouver, Canada
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42
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Abstract
We report a prediction that two prokaryotic proteins contain immunoglobulin superfamily domains. Immunoglobulin-like folds have been identified previously in prokaryotic proteins, but these share no recognizable sequence similarity with eukaryotic immunoglobulin superfamily (IgSF) folds, and may be the result of the physics and chemistry of proteins favoring certain common folds. In contrast, the prokaryotic proteins identified have sequences whose match to the immunoglobulin superfamily can be detected by hidden Markov modeling, BLASTP matches, key residue analysis, and secondary structure predictions. We propose that these prokaryotic immunoglobulin-like domains are almost certain to be related by divergence from a common ancestor to eukaryotic immunoglobulin superfamily domains.
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Affiliation(s)
- A Bateman
- MRC Laboratory of Molecular Biology, Cambridge, England
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43
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Tomme P, Kwan E, Gilkes NR, Kilburn DG, Warren RA. Characterization of CenC, an enzyme from Cellulomonas fimi with both endo- and exoglucanase activities. J Bacteriol 1996; 178:4216-23. [PMID: 8763951 PMCID: PMC178180 DOI: 10.1128/jb.178.14.4216-4223.1996] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The cenC gene, encoding beta-1,4-glucanase C (CenC) from Cellulomonas fimi, was overexpressed in Escherichia coli with a tac-based expression vector. The resulting polypeptide, with an apparent molecular mass of 130 kDa, was purified from the cell extracts by affinity chromatography on cellulose followed by anion-exchange chromatography. N-terminal sequence analysis showed the enzyme to be properly processed. Mature CenC was optimally active at pH 5.0 and 45 degrees C. The enzyme was extremely active on soluble, fluorophoric, and chromophoric glycosides (4-methylumbelliferyl beta-glycosides, 2'-chloro-4'-nitrophenyl-beta-D-cellobioside, and 2'-chloro-4'-nitrophenyl-lactoside) and efficiently hydrolyzed carboxymethyl cellulose, barley beta-glucan, lichenan, and, to a lesser extent, glucomannan. CenC also hydrolyzed acid-swollen cellulose, Avicel, and bacterial microcrystalline cellulose. However, degradation of the latter was slow compared with its degradation by CenB, another C. fimi cellulose belonging to the same enzyme family. CenC acted with inversion of configuration at the anomeric carbon, in accordance with its classification as a family 9 member. The enzyme released mainly cellobiose from soluble cellodextrins and insoluble cellulose. Attack appeared to be from the reducing chain ends. Analysis of carboxymethyl cellulose hydrolysis suggests that CenC is semiprocessive enzyme with both endo- and exoglucanase activities.
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Affiliation(s)
- P Tomme
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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44
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Sakka K, Takada G, Karita S, Ohmiya K. Identification and characterization of cellulose-binding domains in xylanase A of Clostridium stercorarium. Ann N Y Acad Sci 1996; 782:241-51. [PMID: 8659900 DOI: 10.1111/j.1749-6632.1996.tb40565.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The xynA gene encoding a major xylanase of Clostridium stercorarium F-9 was sequenced. The structural gene consists of an open reading frame of 1533 bp encoding a protein of 511 amino acids with an M(r) of 56,519. XynA consists of a catalytic domain belonging to family G at the NH2-terminus and two direct repeats of about 90 amino acids with a short spacing at the COOH-terminus. The repeated sequences, CBDI and CBDII, were not homologous with amino acid sequences of the CBDs classified into families I to V. Nevertheless, XynA showed an affinity for insoluble cellulose such as Avicel. Binding of XynA to Avicel was strongly dependent on the concentration of the incubation buffer and was inhibited by Triton X-100. XynA bound to Avicel (2.4 nmol/g-cellulose) and acid-swollen cellulose (180 nmol/g-cellulose), suggesting that this enzyme has higher affinity for amorphous cellulose than for crystalline cellulose. Functions of CBDI and CBDII were investigated by constructing the mutant enzymes and evaluating the cellulose-binding ability of each of them. XynA4 lacking CBDI and XynA5 lacking CBDII bound to Avicel to a lesser extent than the parental enzyme XynA; but XynA6, devoid of both CBDs, did not bind at all, indicating that CBDI and CBDII each functioned independently as CBD in XynA and their binding capacity was additive. Although the Ruminococcus albus endoglucanase EgIV that was joined to CBDs of XynA acquired cellulose-binding ability, the substrate specificity of EgIV was not altered in the presence or absence of CBDs.
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Affiliation(s)
- K Sakka
- Laboratory of Applied Microbiology, Faculty of Bioresources, Mie University, Tsu, Japan.
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45
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Affiliation(s)
- T Irdani
- Department of Animal Biology and Genetics Leo Pardi, University of Florence, Italy
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46
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Abstract
The bacterium Streptomyces reticuli produces an unusual mycelia-associated cellulase (Avicelase, Cel1) which is solely sufficient to degrade crystalline cellulose to cellobiose. The enzyme consists of a binding domain, one adjoining region with unknown function, and a catalytic domain belonging to the cellulase family E. During cultivation, the strain produces a specific protease which processes the Avicelase to a truncated enzyme lacking the binding domain. The cellulase synthesis is regulated by induction (Avicel) and repression (metabolizable sugars and glycerol).
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Affiliation(s)
- H Schrempf
- FB Biologie/Chemie, Universitat Osnabrück, Germany
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47
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Millward-Sadler SJ, Davidson K, Hazlewood GP, Black GW, Gilbert HJ, Clarke JH. Novel cellulose-binding domains, NodB homologues and conserved modular architecture in xylanases from the aerobic soil bacteria Pseudomonas fluorescens subsp. cellulosa and Cellvibrio mixtus. Biochem J 1995; 312 ( Pt 1):39-48. [PMID: 7492333 PMCID: PMC1136224 DOI: 10.1042/bj3120039] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To test the hypothesis that selective pressure has led to the retention of cellulose-binding domains (CBDs) by hemicellulase enzymes from aerobic bacteria, four new xylanase (xyn) genes from two cellulolytic soil bacteria, Pseudomonas fluorescens subsp. cellulosa and Cellvibrio mixtus, have been isolated and sequenced. Pseudomonas genes xynE and xynF encoded modular xylanases (XYLE and XYLF) with predicted M(r) values of 68,600 and 65000 respectively. XYLE contained a glycosyl hydrolase family 11 catalytic domain at its N-terminus, followed by three other domains; the second of these exhibited sequence identity with NodB from rhizobia. The C-terminal domain (40 residues) exhibited significant sequence identity with a non-catalytic domain of previously unknown function, conserved in all the cellulases and one of the hemicellulases previously characterized from the pseudomonad, and was shown to function as a CBD when fused to the reporter protein glutathione-S-transferase. XYLF contained a C-terminal glycosyl hydrolase family 10 catalytic domain and a novel CBD at its N-terminus. C. mixtus genes xynA and xynB exhibited substantial sequence identity with xynE and xynF respectively, and encoded modular xylanases with the same molecular architecture and, by inference, the same functional properties. In the absence of extensive cross-hybridization between other multiple cel (cellulase) and xyn genes from P. fluorescens subsp. cellulosa and genomic DNA from C. mixtus, similarity between the two pairs of xylanases may indicate a recent transfer of genes between the two bacteria.
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Affiliation(s)
- S J Millward-Sadler
- Department of Biological and Nutritional Sciences, Faculty of Agriculture, The University, Newcastle upon Tyne, U.K
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48
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Shen H, Gilkes NR, Kilburn DG, Miller RC, Warren RA. Cellobiohydrolase B, a second exo-cellobiohydrolase from the cellulolytic bacterium Cellulomonas fimi. Biochem J 1995; 311 ( Pt 1):67-74. [PMID: 7575482 PMCID: PMC1136120 DOI: 10.1042/bj3110067] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The gene cbhB from the cellulolytic bacterium Cellulomonas fimi encodes a polypeptide of 1090 amino acids. Cellobiohydrolase B (CbhB) is 1037 amino acids long, with a calculated molecular mass of 109765 Da. The enzyme comprises five domains: an N-terminal catalytic domain of 643 amino acids, three fibronectin type III repeats of 97 amino acids each, and a C-terminal cellulose-binding domain of 104 amino acids. The catalytic domain belongs to family 48 of glycosyl hydrolases. CbhB has a very low activity on CM-cellulose. Viscometric analysis of CM-cellulose hydrolysis indicates that the enzyme is an exoglucanase. Cellobiose is the major product of hydrolysis of cellulose. In common with two other exoglycanases from C. fimi, CbhB has low but detectable endoglucanase activity. CbhB is the second exo-cellobiohydrolase found in C. fimi. Therefore, the cellulase system of C. fimi resembles those of fungi in comprising multiple endoglucanases and cellobiohydrolases.
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Affiliation(s)
- H Shen
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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49
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Tomme P, Driver DP, Amandoron EA, Miller RC, Antony R, Warren J, Kilburn DG. Comparison of a fungal (family I) and bacterial (family II) cellulose-binding domain. J Bacteriol 1995; 177:4356-63. [PMID: 7635821 PMCID: PMC177184 DOI: 10.1128/jb.177.15.4356-4363.1995] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A family II cellulose-binding domain (CBD) of an exoglucanase/xylanase (Cex) from the bacterium Cellulomonas fimi was replaced with the family I CBD of cellobiohydrolase I (CbhI) from the fungus Trichoderma reesei. Expression of the hybrid gene in Escherichia coli yielded up to 50 mg of the hybrid protein, CexCBDCbhI, per liter of culture supernatant. The hybrid was purified to homogeneity by affinity chromatography on cellulose. The relative association constants (Kr) for the binding of Cex, CexCBDCbhI, the catalytic domain of Cex (p33), and CbhI to bacterial microcrystalline cellulose (BMCC) were 14.9, 7.8, 0.8, and 10.6 liters g-1, respectively. Cex and CexCBDCbhI had similar substrate specificities and similar activities on crystalline and amorphous cellulose. Both released predominantly cellobiose and cellotriose from amorphous cellulose. CexCBDCbhI was two to three times less active than Cex on BMCC, but significantly more active than Cex on soluble cellulose and on xylan. Unlike Cex, the hybrid protein neither bound to alpha-chitin nor released small particles from dewaxed cotton fibers.
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Affiliation(s)
- P Tomme
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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50
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Reinikainen T, Teleman O, Teeri TT. Effects of pH and high ionic strength on the adsorption and activity of native and mutated cellobiohydrolase I from Trichoderma reesei. Proteins 1995; 22:392-403. [PMID: 7479712 DOI: 10.1002/prot.340220409] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cellobiohydrolase I (CBHI) is the major cellulase of Trichoderma reesei. The enzyme contains a discrete cellulose-binding domain (CBD), which increases its binding and activity on crystalline cellulose. We studied cellulase-cellulose interactions using site-directed mutagenesis on the basis of the three-dimensional structure of the CBD of CBHI. Three mutant proteins which have earlier been produced in Saccharomyces cerevisiae were expressed in the native host organism. The data presented here support the hypothesis that a conserved tyrosine (Y492) located on the flat and more hydrophilic surface of the CBD is essential for the functionality. The data also suggest that the more hydrophobic surface is not directly involved in the CBD function. The pH dependence of the adsorption revealed that electrostatic repulsion between the bound proteins may also control the adsorption. The binding of CBHI to cellulose was significantly affected by high ionic strength suggesting that the interaction with cellulose includes a hydrophobic effect. High ionic strength increased the activity of the isolated core and of mutant proteins on crystalline cellulose, indicating that once productively bound, the enzymes are capable of solubilizing cellulose even with a mutagenized or with no CBD.
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