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Iacono R, De Lise F, Moracci M, Cobucci-Ponzano B, Strazzulli A. Glycoside hydrolases from (hyper)thermophilic archaea: structure, function, and applications. Essays Biochem 2023; 67:731-751. [PMID: 37341134 DOI: 10.1042/ebc20220196] [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: 02/28/2023] [Revised: 04/19/2023] [Accepted: 05/31/2023] [Indexed: 06/22/2023]
Abstract
(Hyper)thermophilic archaeal glycosidases are enzymes that catalyze the hydrolysis of glycosidic bonds to break down complex sugars and polysaccharides at high temperatures. These enzymes have an unique structure that allows them to remain stable and functional in extreme environments such as hot springs and hydrothermal vents. This review provides an overview of the current knowledge and milestones on the structures and functions of (hyper)thermophilic archaeal glycosidases and their potential applications in various fields. In particular, this review focuses on the structural characteristics of these enzymes and how these features relate to their catalytic activity by discussing different types of (hyper)thermophilic archaeal glycosidases, including β-glucosidases, chitinase, cellulases and α-amylases, describing their molecular structures, active sites, and mechanisms of action, including their role in the hydrolysis of carbohydrates. By providing a comprehensive overview of (hyper)thermophilic archaeal glycosidases, this review aims to stimulate further research into these fascinating enzymes.
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Affiliation(s)
- Roberta Iacono
- Department of Biology, University of Naples "Federico II", Complesso Universitario Di Monte S. Angelo, Via Cupa Nuova Cinthia 21, Naples, 80126, Italy
| | - Federica De Lise
- Institute of Biosciences and BioResources, National Research Council of Italy, Via P. Castellino 111, Naples, 80131, Italy
| | - Marco Moracci
- Department of Biology, University of Naples "Federico II", Complesso Universitario Di Monte S. Angelo, Via Cupa Nuova Cinthia 21, Naples, 80126, Italy
- Institute of Biosciences and BioResources, National Research Council of Italy, Via P. Castellino 111, Naples, 80131, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, 80100 Naples, Italy
- NBFC, National Biodiversity Future Center, 90133 Palermo, Italy
| | - Beatrice Cobucci-Ponzano
- Institute of Biosciences and BioResources, National Research Council of Italy, Via P. Castellino 111, Naples, 80131, Italy
| | - Andrea Strazzulli
- Department of Biology, University of Naples "Federico II", Complesso Universitario Di Monte S. Angelo, Via Cupa Nuova Cinthia 21, Naples, 80126, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, 80100 Naples, Italy
- NBFC, National Biodiversity Future Center, 90133 Palermo, Italy
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2
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(Hyper)Thermophilic Enzymes: Production and Purification. Methods Mol Biol 2020. [PMID: 33128766 DOI: 10.1007/978-1-0716-0775-6_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The discovery of thermophilic and hyperthermophilic microorganisms, thriving at environmental temperatures near or above 100 °C, has revolutionized our ideas about the upper temperature limit at which life can exist. The characterization of (hyper)thermostable proteins has broadened our understanding and presented new opportunities for solving one of the most challenging problems in biophysics: how are structural stability and biological function maintained at high temperatures where "normal" proteins undergo dramatic structural changes? In our laboratory, we have purified and studied many thermostable and hyperthermostable proteins in an attempt to determine the molecular basis of heat stability. Here, we present methods to express such proteins and enzymes in E. coli and provide a general protocol for overproduction and purification. The ability to produce enzymes that retain their stability and activity at elevated temperatures creates exciting opportunities for a wide range of biocatalytic applications.
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Structural Insights into the Molecular Evolution of the Archaeal Exo-β-d-Glucosaminidase. Int J Mol Sci 2019; 20:ijms20102460. [PMID: 31109049 PMCID: PMC6566704 DOI: 10.3390/ijms20102460] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/16/2022] Open
Abstract
The archaeal exo-β-d-glucosaminidase (GlmA), a thermostable enzyme belonging to the glycosidase hydrolase (GH) 35 family, hydrolyzes chitosan oligosaccharides into monomer glucosamines. GlmA is a novel enzyme in terms of its primary structure, as it is homologous to both GH35 and GH42 β-galactosidases. The catalytic mechanism of GlmA is not known. Here, we summarize the recent reports on the crystallographic analysis of GlmA. GlmA is a homodimer, with each subunit comprising three distinct domains: a catalytic TIM-barrel domain, an α/β domain, and a β1 domain. Surprisingly, the structure of GlmA presents features common to GH35 and GH42 β-galactosidases, with the domain organization resembling that of GH42 β-galactosidases and the active-site architecture resembling that of GH35 β-galactosidases. Additionally, the GlmA structure also provides critical information about its catalytic mechanism, in particular, on how the enzyme can recognize glucosamine. Finally, we postulate an evolutionary pathway based on the structure of an ancestor GlmA to extant GH35 and GH42 β-galactosidases.
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Westphal AH, Geerke-Volmer AA, van Mierlo CPM, van Berkel WJH. Chaotropic heat treatment resolves native-like aggregation of a heterologously produced hyperthermostable laminarinase. Biotechnol J 2017; 12. [PMID: 28403549 DOI: 10.1002/biot.201700007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 11/10/2022]
Abstract
Production of hyperthermostable enzymes in mesophilic hosts frequently causes undesired aggregation of these proteins. During production of Pyrococcus furiosus endo-β-1,3 glucanase (LamA) in Escherichia coli, soluble and insoluble species form. Here, the authors address the composition of this mixture, including the nature of LamA conformers, and establish a method to increase the yield of native monomer. With gel electrophoresis, size-exclusion chromatography, light scattering, circular dichroism and enzyme kinetics the authors show that approximately 50 % of heterologously produced LamA is soluble, and that 40 % of this fraction constitutes native-like oligomers and non-native monomers. Soluble oligomers display, like native LamA monomer, substrate inhibition, although with poor activity. Treatment of soluble oligomers with 3 M guanidinium hydrochloride at 80 °C yields up to 75 % properly active monomer. Non-native monomer shows low specific activity without substrate inhibition. Incubating non-native monomer with 3 M guanidinium hydrochloride at 80 °C causes formation of 25 % native LamA. Also, a large amount of insoluble LamA aggregates can be converted into soluble native monomer by application of this procedure. Thus, chaotropic heat treatment can improve the yield and quality of hyperthermostable proteins that form aberrant species during production in E. coli.
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Affiliation(s)
- Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
| | - Astrid A Geerke-Volmer
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands.,Present address: Technology & Support, Aspen Oss B.V., Oss, The Netherlands
| | - Carlo P M van Mierlo
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
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5
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Patterson DP, LaFrance B, Douglas T. Rescuing recombinant proteins by sequestration into the P22 VLP. Chem Commun (Camb) 2014; 49:10412-4. [PMID: 24079011 DOI: 10.1039/c3cc46517a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Here we report the use of a self-assembling protein cage to sequester and solubilize recombinant proteins which are usually trafficked to insoluble inclusion bodies. Our results suggest that protein cages can be used as novel vehicles to rescue and produce soluble proteins that are otherwise difficult to obtain using conventional methods.
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Affiliation(s)
- Dustin P Patterson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
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6
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Falcicchio P, Levisson M, Kengen SWM, Koutsopoulos S. (Hyper)thermophilic enzymes: production and purification. Methods Mol Biol 2014; 1129:487-496. [PMID: 24648095 DOI: 10.1007/978-1-62703-977-2_34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The discovery of thermophilic and hyperthermophilic microorganisms, thriving at environmental temperatures near or above 100 °C, has revolutionized our ideas about the upper temperature limit at which life can exist. The characterization of (hyper)thermostable proteins has broadened our understanding and presented new opportunities for solving one of the most challenging problems in biophysics: how is structural stability and biological function maintained at high temperatures where "normal" proteins undergo dramatic structural changes? In our laboratory we have purified and studied many thermostable and hyperthermostable proteins in an attempt to determine the molecular basis of heat stability. Here, we present methods to express such proteins and enzymes in E. coli and provide a general protocol for overproduction and purification. The ability to produce enzymes that retain their stability and activity at elevated temperatures creates exciting opportunities for a wide range of biocatalytic applications.
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7
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Thermococcus kodakarensis genetics: TK1827-encoded beta-glycosidase, new positive-selection protocol, and targeted and repetitive deletion technology. Appl Environ Microbiol 2009; 76:1044-52. [PMID: 20023088 DOI: 10.1128/aem.02497-09] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inactivation of TK1761, the reporter gene established for Thermococcus kodakarensis, revealed the presence of a second beta-glycosidase that we have identified as the product of TK1827. This enzyme (pTK1827) has been purified and shown to hydrolyze glucopyranoside but not mannopyranoside, have optimal activity at 95 degrees C and from pH 8 to 9.5, and have a functional half-life of approximately 7 min at 100 degrees C. To generate a strain with both TK1761 and TK1827 deleted, a new selection/counterselection protocol has been developed, and the levels of beta-glycosidase activity in T. kodakarensis strains with TK1761 and/or TK1827 deleted and with these genes expressed from heterologous promoters are described. Genetic tools and strains have been developed that extend the use of this selection/counterselection procedure to delete any nonessential gene from the T. kodakarensis chromosome. Using this technology, TK0149 was deleted to obtain an agmatine auxotroph that grows on nutrient-rich medium only when agmatine is added. Transformants can therefore be selected rapidly, and replicating plasmids can be maintained in this strain growing in rich medium by complementation of the TK0149 deletion.
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van Lieshout JF, Verhees CH, Ettema TJ, van der Sar S, Imamura H, Matsuzawa H, van der Oost J, de Vos WM. Identification and Molecular Characterization of a Novel Type of α-galactosidase fromPyrococcus furiosus. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420310001614342] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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VanFossen AL, Lewis DL, Nichols JD, Kelly RM. Polysaccharide Degradation and Synthesis by Extremely Thermophilic Anaerobes. Ann N Y Acad Sci 2008; 1125:322-37. [DOI: 10.1196/annals.1419.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Ilari A, Fiorillo A, Angelaccio S, Florio R, Chiaraluce R, van der Oost J, Consalvi V. Crystal structure of a family 16 endoglucanase from the hyperthermophile Pyrococcus furiosus--structural basis of substrate recognition. FEBS J 2008; 276:1048-58. [PMID: 19154353 DOI: 10.1111/j.1742-4658.2008.06848.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacterial and archaeal endo-beta-1,3-glucanases that belong to glycoside hydrolase family 16 share a beta-jelly-roll fold, but differ significantly in sequence and in substrate specificity. The crystal structure of the laminarinase (EC 3.2.1.39) from the hyperthermophilic archaeon Pyrococcus furiosus (pfLamA) has been determined at 2.1 A resolution by molecular replacement. The pfLamA structure reveals a kink of six residues (72-77) at the entrance of the catalytic cleft. This peptide is absent in the endoglucanases from alkaliphilic Nocardiopsis sp. strain F96 and Bacillus macerans, two proteins displaying an overall fold similar to that of pfLamA, but with different substrate specificity. A deletion mutant of pfLamA, lacking residues 72-75, hydrolyses the mixed-linkage beta-1,3-1,4-glucan lichenan 10 times more efficiently than the wild-type protein, indicating the importance of the kink in substrate preference.
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Affiliation(s)
- Andrea Ilari
- CNR Institute of Molecular Biology and Pathology, Italy.
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11
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Chiaraluce R, Florio R, Angelaccio S, Gianese G, van Lieshout JFT, van der Oost J, Consalvi V. Tertiary structure in 7.9 m guanidinium chloride − the role of Glu53 and Asp287 in Pyrococcus furiosus endo-β-1,3-glucanase. FEBS J 2007; 274:6167-79. [DOI: 10.1111/j.1742-4658.2007.06137.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chiaraluce R, Florio R, Angelaccio S, Gianese G, van Lieshout JFT, van der Oost J, Consalvi V. Tertiary structure in 7.9 m guanidinium chloride − the role of Glu53 and Asp287 in Pyrococcus furiosus endo-β-1,3-glucanase. FEBS J 2007. [DOI: 10.1111/j.1742-4658.2007.6137.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Chiaraluce R, Gianese G, Angelaccio S, Florio R, van Lieshout J, van der Oost J, Consalvi V. Calcium-induced tertiary structure modifications of endo-beta-1,3-glucanase from Pyrococcus furiosus in 7.9 M guanidinium chloride. Biochem J 2005; 386:515-24. [PMID: 15482259 PMCID: PMC1134870 DOI: 10.1042/bj20041137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The family 16 endo-beta-1,3 glucanase from the extremophilic archaeon Pyrococcus furiosus is a laminarinase, which in 7.9 M GdmCl (guanidinium chloride) maintains a significant amount of tertiary structure without any change of secondary structure. The addition of calcium to the enzyme in 7.9 M GdmCl causes significant changes to the near-UV CD and fluorescence spectra, suggesting a notable increase in the tertiary structure which leads to a state comparable, but not identical, to the native state. The capability to interact with calcium in 7.9 M GdmCl with a consistent recovery of native tertiary structure is a unique property of this extremely stable endo-beta-1,3 glucanase. The effect of calcium on the thermodynamic parameters relative to the GdmCl-induced equilibrium unfolding has been analysed by CD and fluorescence spectroscopy. The interaction of calcium with the native form of the enzyme is studied by Fourier-transform infrared spectroscopy in the absorption region of carboxylate groups and by titration in the presence of a chromophoric chelator. A homology-based model of the enzyme is generated and used to predict the putative binding site(s) for calcium and the structural interactions potentially responsible for the unusual stability of this protein, in comparison with other family 16 glycoside hydrolases.
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Affiliation(s)
- Roberta Chiaraluce
- *Dipartimento di Scienze Biochimiche ‘A Rossi Fanelli’, Università ‘La Sapienza’, P.le A. Moro 5, 00185 Rome, Italy
| | - Giulio Gianese
- *Dipartimento di Scienze Biochimiche ‘A Rossi Fanelli’, Università ‘La Sapienza’, P.le A. Moro 5, 00185 Rome, Italy
| | - Sebastiana Angelaccio
- *Dipartimento di Scienze Biochimiche ‘A Rossi Fanelli’, Università ‘La Sapienza’, P.le A. Moro 5, 00185 Rome, Italy
| | - Rita Florio
- *Dipartimento di Scienze Biochimiche ‘A Rossi Fanelli’, Università ‘La Sapienza’, P.le A. Moro 5, 00185 Rome, Italy
| | - Johan F. T. van Lieshout
- †Laboratory of Microbiology, Wageningen University, H. van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands
| | - John van der Oost
- †Laboratory of Microbiology, Wageningen University, H. van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands
| | - Valerio Consalvi
- *Dipartimento di Scienze Biochimiche ‘A Rossi Fanelli’, Università ‘La Sapienza’, P.le A. Moro 5, 00185 Rome, Italy
- To whom correspondence should be addressed (email )
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Van Lieshout J, Faijes M, Nieto J, Van Der Oost J, Planas A. Hydrolase and glycosynthase activity of endo-1,3-beta-glucanase from the thermophile Pyrococcus furiosus. ARCHAEA (VANCOUVER, B.C.) 2004; 1:285-92. [PMID: 15810439 PMCID: PMC2685573 DOI: 10.1155/2004/731548] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Accepted: 08/04/2004] [Indexed: 11/18/2022]
Abstract
Pyrococcus furiosus laminarinase (LamA, PF0076) is an endo-glycosidase that hydrolyzes beta-1,3-glucooligosaccharides, but not beta-1,4-gluco-oligosaccharides. We studied the specificity of LamA towards small saccharides by using 4-methylumbelliferyl beta-glucosides with different linkages. Besides endo-activity, wild-type LamA has some exo-activity, and catalyzes the hydrolysis of mixed-linked oligosaccharides (Glcbeta4Glcbeta3Glcbeta-MU (Glc = glucosyl, MU = 4-methylumbelliferyl)) with both beta-1,4 and beta-1,3 specificities. The LamA mutant E170A had severely reduced hydrolytic activity, which is consistent with Glu170 being the catalytic nucleophile. The E170A mutant was active as a glycosynthase, catalyzing the condensation of alpha-laminaribiosyl fluoride to different acceptors. The best condensation yields were found at pH 6.5 and 50 degrees C, but did not exceed 30%. Depending on the acceptor, the synthase generated either a beta-1,3 or a beta-1,4 linkage.
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Affiliation(s)
- J. Van Lieshout
- Laboratory for Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT, Wageningen, The Netherlands
| | - M. Faijes
- Laboratory of Biochemistry, Institut Químic de Sarriá, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - J. Nieto
- Laboratory of Biochemistry, Institut Químic de Sarriá, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - J. Van Der Oost
- Laboratory for Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT, Wageningen, The Netherlands
| | - A. Planas
- Laboratory of Biochemistry, Institut Químic de Sarriá, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
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Verhees CH, Kengen SWM, Tuininga JE, Schut GJ, Adams MWW, De Vos WM, Van Der Oost J. The unique features of glycolytic pathways in Archaea. Biochem J 2003; 375:231-46. [PMID: 12921536 PMCID: PMC1223704 DOI: 10.1042/bj20021472] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2002] [Revised: 05/16/2003] [Accepted: 08/18/2003] [Indexed: 11/17/2022]
Abstract
An early divergence in evolution has resulted in two prokaryotic domains, the Bacteria and the Archaea. Whereas the central metabolic routes of bacteria and eukaryotes are generally well-conserved, variant pathways have developed in Archaea involving several novel enzymes with a distinct control. A spectacular example of convergent evolution concerns the glucose-degrading pathways of saccharolytic archaea. The identification, characterization and comparison of the glycolytic enzymes of a variety of phylogenetic lineages have revealed a mosaic of canonical and novel enzymes in the archaeal variants of the Embden-Meyerhof and the Entner-Doudoroff pathways. By means of integrating results from biochemical and genetic studies with recently obtained comparative and functional genomics data, the structure and function of the archaeal glycolytic routes, the participating enzymes and their regulation are re-evaluated.
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Affiliation(s)
- Corné H Verhees
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands
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Tanaka T, Fukui T, Atomi H, Imanaka T. Characterization of an exo-beta-D-glucosaminidase involved in a novel chitinolytic pathway from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. J Bacteriol 2003; 185:5175-81. [PMID: 12923090 PMCID: PMC181003 DOI: 10.1128/jb.185.17.5175-5181.2003] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously clarified that the chitinase from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 produces diacetylchitobiose (GlcNAc(2)) as an end product from chitin. Here we sought to identify enzymes in T. kodakaraensis that were involved in the further degradation of GlcNAc(2). Through a search of the T. kodakaraensis genome, one candidate gene identified as a putative beta-glycosyl hydrolase was found in the near vicinity of the chitinase gene. The primary structure of the candidate protein was homologous to the beta-galactosidases in family 35 of glycosyl hydrolases at the N-terminal region, whereas the central region was homologous to beta-galactosidases in family 42. The purified protein from recombinant Escherichia coli clearly showed an exo-beta-D-glucosaminidase (GlcNase) activity but not beta-galactosidase activity. This GlcNase (GlmA(Tk)), a homodimer of 90-kDa subunits, exhibited highest activity toward reduced chitobiose at pH 6.0 and 80 degrees C and specifically cleaved the nonreducing terminal glycosidic bond of chitooligosaccharides. The GlcNase activity was also detected in T. kodakaraensis cells, and the expression of GlmA(Tk) was induced by GlcNAc(2) and chitin, strongly suggesting that GlmA(Tk) is involved in chitin catabolism in T. kodakaraensis. These results suggest that T. kodakaraensis, unlike other organisms, possesses a novel chitinolytic pathway where GlcNAc(2) from chitin is first deacetylated and successively hydrolyzed to glucosamine. This is the first report that reveals the primary structure of GlcNase not only from an archaeon but also from any organism.
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Affiliation(s)
- Takeshi Tanaka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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Kaper T, Brouns SJJ, Geerling ACM, De Vos WM, Van der Oost J. DNA family shuffling of hyperthermostable beta-glycosidases. Biochem J 2002; 368:461-70. [PMID: 12164784 PMCID: PMC1222993 DOI: 10.1042/bj20020726] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2002] [Revised: 07/16/2002] [Accepted: 08/06/2002] [Indexed: 11/17/2022]
Abstract
The structural compatibility of two hyperthermostable family 1 glycoside hydrolases, Pyrococcus furiosus CelB and Sulfolobus solfataricus LacS, as well as their kinetic potential were studied by construction of a library of 2048 hybrid beta-glycosidases using DNA family shuffling. The hybrids were tested for their thermostability, ability to hydrolyse lactose and sensitivity towards inhibition by glucose. Three screening rounds at 70 degrees C led to the isolation of three high-performance hybrid enzymes (hybrid 11, 18 and 20) that had 1.5-3.5-fold and 3.5-8.6-fold increased lactose hydrolysis rates compared with parental CelB and LacS respectively. The three variants were the result of a single crossover event, which gave rise to hybrids with a LacS N-terminus and a main CelB sequence. Constructed three-dimensional models of the hybrid enzymes revealed that the catalytic (betaalpha)(8)-barrel was composed of both LacS and CelB elements. In addition, an extra intersubunit hydrogen bond in hybrids 18 and 20 might explain their superior stability over hybrid 11. This study demonstrates that extremely thermostable enzymes with limited homology and different mechanisms of stabilization can be efficiently shuffled to form stable hybrids with improved catalytic features.
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Affiliation(s)
- Thijs Kaper
- Laboratory of Microbiology, Wageningen University, Hessenlink van Suchtelenweg 4, NL-6703 CT Wageningen, The Netherlands
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