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Yang Y, Zhang L, Guo M, Sun J, Matsukawa S, Xie J, Wei D. Novel α-L-arabinofuranosidase from Cellulomonas fimi ATCC 484 and its substrate-specificity analysis with the aid of computer. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:3725-33. [PMID: 25797391 DOI: 10.1021/jf5059683] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In the process of gene mining for novel α-L-arabinofuranosidases (AFs), the gene Celf_3321 from Cellulomonas fimi ATCC 484 encodes an AF, termed as AbfCelf, with potent activity, 19.4 U/mg under the optimum condition, pH 6.0 and 40 °C. AbfCelf can hydrolyze α-1,5-linked oligosaccharides, sugar beet arabinan, linear 1,5-α-arabinan, and wheat flour arabinoxylan, which is partly different from some previously well-characterized GH 51 AFs. The traditional substrate-specificity analysis for AFs is labor-consuming and money costing, because the substrates include over 30 kinds of various 4-nitrophenol (PNP)-glycosides, oligosaccharides, and polysaccharides. Hence, a preliminary structure and mechanism based method was applied for substrate-specificity analysis. The binding energy (ΔG, kcal/mol) obtained by docking suggested the reaction possibility and coincided with the experimental results. AbfA crystal 1QW9 was used to test the rationality of docking method in simulating the interaction between enzyme and substrate, as well the credibility of the substrate-specificity analysis method in silico.
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Affiliation(s)
- Ying Yang
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
| | - Lujia Zhang
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
| | - Mingrong Guo
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
| | - Jiaqi Sun
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
| | - Shingo Matsukawa
- §Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan
| | - Jingli Xie
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
- ‡Shanghai Collaborative Innovation Center for Biomanufacturing, Shanghai 200237, People's Republic of China
| | - Dongzhi Wei
- †State Key Laboratory of Bioreactor Engineering, Department of Food Science and Technology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, People's Republic of China
- ‡Shanghai Collaborative Innovation Center for Biomanufacturing, Shanghai 200237, People's Republic of China
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Hoedemaekers K, Derksen J, Hoogstrate SW, Wolters-Arts M, Oh SA, Twell D, Mariani C, Rieu I. BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2015; 206:255-267. [PMID: 25442716 DOI: 10.1111/nph.13200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/28/2014] [Indexed: 05/02/2023]
Abstract
Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery.
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Affiliation(s)
- Karin Hoedemaekers
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Jan Derksen
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Suzanne W Hoogstrate
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Mieke Wolters-Arts
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Sung-Aeong Oh
- Department of Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - David Twell
- Department of Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Celestina Mariani
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
| | - Ivo Rieu
- Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands
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Sulzenbacher G, Roig-Zamboni V, Peumans WJ, Henrissat B, van Damme EJM, Bourne Y. Structural basis for carbohydrate binding properties of a plant chitinase-like agglutinin with conserved catalytic machinery. J Struct Biol 2015; 190:115-21. [PMID: 25727185 DOI: 10.1016/j.jsb.2015.01.013] [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: 10/21/2014] [Revised: 01/24/2015] [Accepted: 01/27/2015] [Indexed: 01/13/2023]
Abstract
A new chitinase-like agglutinin, RobpsCRA, related to family GH18 chitinases, has previously been identified in black locust (Robinia pseudoacacia) bark. The crystal structure of RobpsCRA at 1.85Å resolution reveals unusual molecular determinants responsible for the lack of its ancestral chitinase activity. Unlike other chitinase-like proteins, which lack chitinase catalytic residues, RobpsCRA has conserved its catalytic machinery. However, concerted rearrangements of loop regions coupled to non-conservative substitutions of aromatic residues central to the chitin-binding groove explain the lack of hydrolytic activity against chitin and the switch toward recognition of high-mannose type N-glycans. Identification of close homologs in flowering plants with conservation of sequence motifs associated to the structural adaptations seen in RobpsCRA defines an emerging class of agglutinins, as emphasized by a phylogenetic analysis, that are likely to share a similar carbohydrate binding specificity for high-mannose type N-glycans. This study illustrates the recent evolution and molecular adaptation of a versatile TIM-barrel scaffold within the ancestral GH18 family.
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Affiliation(s)
- Gerlind Sulzenbacher
- Aix-Marseille University, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Véronique Roig-Zamboni
- Aix-Marseille University, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Willy J Peumans
- Department of Molecular Biotechnology, Laboratory of Biochemistry and Glycobiology, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Bernard Henrissat
- Aix-Marseille University, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France
| | - Els J M van Damme
- Department of Molecular Biotechnology, Laboratory of Biochemistry and Glycobiology, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Yves Bourne
- Aix-Marseille University, AFMB UMR 7257, 13288 Marseille, France; CNRS, AFMB UMR 7257, 13288 Marseille, France.
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Busk PK, Lange M, Pilgaard B, Lange L. Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature. PLoS One 2014; 9:e114138. [PMID: 25461894 PMCID: PMC4252092 DOI: 10.1371/journal.pone.0114138] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 11/03/2014] [Indexed: 12/30/2022] Open
Abstract
The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence. In the present study we further developed the method Peptide Pattern Recognition to an automatic approach not only to find all genes encoding glycoside hydrolases and lytic polysaccharide monooxygenases in fungal genomes but also to predict the function of the genes. The functional annotation is an important feature as it provides a direct route to predict function from primary sequence. Furthermore, we used Peptide Pattern Recognition to compare the cellulose-degrading enzyme activities encoded by 39 fungal genomes. The results indicated that cellobiohydrolases and AA9 lytic polysaccharide monooxygenases are hallmarks of cellulose-degrading fungi except brown rot fungi. Furthermore, a high number of AA9, endocellulase and β-glucosidase genes were identified, not in what are known to be the strongest, specialized lignocellulose degraders but in saprophytic fungi that can use a wide variety of substrates whereas only few of these genes were found in fungi that have a limited number of natural, lignocellulotic substrates. This correlation suggests that enzymes with different properties are necessary for degradation of cellulose in different complex substrates. Interestingly, clustering of the fungi based on their predicted enzymes indicated that Ascomycota and Basidiomycota use the same enzymatic activities to degrade plant cell walls.
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Affiliation(s)
- Peter K. Busk
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, A.C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
- * E-mail:
| | - Mette Lange
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, A.C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
| | - Bo Pilgaard
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, A.C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
| | - Lene Lange
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, A.C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
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Lipski A, Hervé M, Lombard V, Nurizzo D, Mengin-Lecreulx D, Bourne Y, Vincent F. Structural and biochemical characterization of the β-N-acetylglucosaminidase from Thermotoga maritima: toward rationalization of mechanistic knowledge in the GH73 family. Glycobiology 2014; 25:319-30. [PMID: 25344445 DOI: 10.1093/glycob/cwu113] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Members of the GH73 glycosidase family cleave the β-1,4-glycosidic bond between the N-acetylglucosaminyl (GlcNAc) and N-acetylmuramyl (MurNAc) moieties in bacterial peptidoglycan. A catalytic mechanism has been proposed for members FlgJ, Auto, AcmA and Atl(WM) and the structural analysis of FlgJ and Auto revealed a conserved α/β fold reminiscent of the distantly related GH23 lysozyme. Comparison of the active site residues reveals variability in the nature of the catalytic general base suggesting two distinct catalytic mechanisms: an inverting mechanism involving two distant glutamate residues and a substrate-assisted mechanism involving anchimeric assistance by the C2-acetamido group of the GlcNAc moiety. Herein, we present the biochemical characterization and crystal structure of TM0633 from the hyperthermophilic bacterium Thermotoga maritima. TM0633 adopts the α/β fold of the family and displays β-N-acetylglucosaminidase activity on intact peptidoglycan sacculi. Site-directed mutagenesis identifies Glu34, Glu65 and Tyr118 as important residues for catalysis. A thorough bioinformatic analysis of the GH73 sequences identified five phylogenetic clusters. TM0633, FlgJ and Auto belong to a group of three clusters that conserve two carboxylate residues involved in a classical inverting acid-base mechanism. Members of the other two clusters lack a conserved catalytic general base supporting a substrate-assisted mechanism. Molecular modeling of representative members from each cluster suggests that variability in length of the β-hairpin region above the active site confers ligand-binding specificity and modulates the catalytic mechanisms within the GH73 family.
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Affiliation(s)
- Alexandra Lipski
- Laboratory for Biocrystallography and Structural Biology of Therapeutic Targets, Molecular and Structural Bases of Infectious Diseases, UMR 5086 CNRS and University of Lyon, 7 passage du Vercors, F-69367 Lyon Cedex 07, France CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Mireille Hervé
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université de Paris-Sud, 91405 Orsay, France
| | - Vincent Lombard
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Didier Nurizzo
- European Synchrotron Radiation Facility, Polygone Scientifique Louis Néel, 6 rue Jules Horowitz, 38000 Grenoble, France
| | - Dominique Mengin-Lecreulx
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université de Paris-Sud, 91405 Orsay, France
| | - Yves Bourne
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Florence Vincent
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
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Hjort K, Presti I, Elväng A, Marinelli F, Sjöling S. Bacterial chitinase with phytopathogen control capacity from suppressive soil revealed by functional metagenomics. Appl Microbiol Biotechnol 2014; 98:2819-28. [PMID: 24121932 PMCID: PMC3936118 DOI: 10.1007/s00253-013-5287-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/08/2013] [Accepted: 09/12/2013] [Indexed: 12/16/2022]
Abstract
Plant disease caused by fungal pathogens results in vast crop damage globally. Microbial communities of soil that is suppressive to fungal crop disease provide a source for the identification of novel enzymes functioning as bioshields against plant pathogens. In this study, we targeted chitin-degrading enzymes of the uncultured bacterial community through a functional metagenomics approach, using a fosmid library of a suppressive soil metagenome. We identified a novel bacterial chitinase, Chi18H8, with antifungal activity against several important crop pathogens. Sequence analyses show that the chi18H8 gene encodes a 425-amino acid protein of 46 kDa with an N-terminal signal peptide, a catalytic domain with the conserved active site F175DGIDIDWE183, and a chitinase insertion domain. Chi18H8 was expressed (pGEX-6P-3 vector) in Escherichia coli and purified. Enzyme characterization shows that Chi18H8 has a prevalent chitobiosidase activity with a maximum activity at 35 °C at pH lower than 6, suggesting a role as exochitinase on native chitin. To our knowledge, Chi18H8 is the first chitinase isolated from a metagenome library obtained in pure form and which has the potential to be used as a candidate agent for controlling fungal crop diseases. Furthermore, Chi18H8 may also answer to the demand for novel chitin-degrading enzymes for a broad range of other industrial processes and medical purposes.
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Affiliation(s)
- Karin Hjort
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ilaria Presti
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, 21100 Italy
| | - Annelie Elväng
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, 21100 Italy
- The Protein Factory Research Center, Politecnico of Milano, ICRM CNR and University of Insubria, Varese, 21100 Italy
| | - Sara Sjöling
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
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Jain I, Kumar V, Satyanarayana T. Applicability of recombinant β-xylosidase from the extremely thermophilic bacterium Geobacillus thermodenitrificans in synthesizing alkylxylosides. BIORESOURCE TECHNOLOGY 2014; 170:462-469. [PMID: 25164338 DOI: 10.1016/j.biortech.2014.07.113] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 07/26/2014] [Accepted: 07/28/2014] [Indexed: 06/03/2023]
Abstract
The β-xylosidase encoding gene (XsidB) of the extremely thermophilic bacterium Geobacillus thermodenitrificans has been cloned and expressed in Escherichia coli. The homotrimeric recombinant XsidB is of 204.0kDa, which is optimally active at 60°C and pH 7.0 with T1/2 of 58min at 70°C. The β-xylosidase remains unaffected in the presence of most metal ions and organic solvents. The Km [p-nitrophenyl β-xyloside (pNPX)], Vmax and kcat values of the enzyme are 2×10(-3)M, 1250μmolesmg(-1)min(-1) and 13.20×10(5)min(-1), respectively. The enzyme catalyzes transxylosylation reactions in the presence of alcohols as acceptors. The pharmaceutically important β-methyl-d-xylosides could be produced using pNPX as the donor and methanol as acceptor. The products of transxylosylation were identified by TLC and HPLC, and the structure was confirmed by (1)H NMR analysis. The enzyme is also useful in synthesizing transxylosylation products from the wheat bran hydrolysate.
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Affiliation(s)
- Ira Jain
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
| | - Vikash Kumar
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
| | - T Satyanarayana
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
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Blackman LM, Cullerne DP, Hardham AR. Bioinformatic characterisation of genes encoding cell wall degrading enzymes in the Phytophthora parasitica genome. BMC Genomics 2014; 15:785. [PMID: 25214042 PMCID: PMC4176579 DOI: 10.1186/1471-2164-15-785] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 09/03/2014] [Indexed: 12/13/2022] Open
Abstract
Background A critical aspect of plant infection by the majority of pathogens is penetration of the plant cell wall. This process requires the production and secretion of a broad spectrum of pathogen enzymes that target and degrade the many complex polysaccharides in the plant cell wall. As a necessary framework for a study of the expression of cell wall degrading enzymes (CWDEs) produced by the broad host range phytopathogen, Phytophthora parasitica, we have conducted an in-depth bioinformatics analysis of the entire complement of genes encoding CWDEs in this pathogen’s genome. Results Our bioinformatic analysis indicates that 431 (2%) of the 20,825 predicted proteins encoded by the P. parasitica genome, are carbohydrate-active enzymes (CAZymes) involved in the degradation of cell wall polysaccharides. Of the 431 proteins, 337 contain classical N-terminal secretion signals and 67 are predicted to be targeted to the non-classical secretion pathway. Identification of CAZyme catalytic activity based on primary protein sequence is difficult, nevertheless, detailed comparisons with previously characterized enzymes has allowed us to determine likely enzyme activities and targeted substrates for many of the P. parasitica CWDEs. Some proteins (12%) contain more than one CAZyme module but, in most cases, multiple modules are from the same CAZyme family. Only 12 P. parasitica CWDEs contain both catalytically-active (glycosyl hydrolase) and non-catalytic (carbohydrate binding) modules, a situation that contrasts with that in fungal phytopathogens. Other striking differences between the complements of CWDEs in P. parasitica and fungal phytopathogens are seen in the CAZyme families that target cellulose, pectins or β-1,3-glucans (e.g. callose). About 25% of P. parasitica CAZymes are solely directed towards pectin degradation, with the majority coming from pectin lyase or carbohydrate esterase families. Fungal phytopathogens typically contain less than half the numbers of these CAZymes. The P. parasitica genome, like that of other Oomycetes, is rich in CAZymes that target β-1,3-glucans. Conclusions This detailed analysis of the full complement of P. parasitica cell wall degrading enzymes provides a framework for an in-depth study of patterns of expression of these pathogen genes during plant infection and the induction or repression of expression by selected substrates. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-785) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Leila M Blackman
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 0200, Australia.
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Moebius N, Üzüm Z, Dijksterhuis J, Lackner G, Hertweck C. Active invasion of bacteria into living fungal cells. eLife 2014; 3:e03007. [PMID: 25182414 PMCID: PMC4166002 DOI: 10.7554/elife.03007] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/29/2014] [Indexed: 12/12/2022] Open
Abstract
The rice seedling blight fungus Rhizopus microsporus and its endosymbiont Burkholderia rhizoxinica form an unusual, highly specific alliance to produce the highly potent antimitotic phytotoxin rhizoxin. Yet, it has remained a riddle how bacteria invade the fungal cells. Genome mining for potential symbiosis factors and functional analyses revealed that a type 2 secretion system (T2SS) of the bacterial endosymbiont is required for the formation of the endosymbiosis. Comparative proteome analyses show that the T2SS releases chitinolytic enzymes (chitinase, chitosanase) and chitin-binding proteins. The genes responsible for chitinolytic proteins and T2SS components are highly expressed during infection. Through targeted gene knock-outs, sporulation assays and microscopic investigations we found that chitinase is essential for bacteria to enter hyphae. Unprecedented snapshots of the traceless bacterial intrusion were obtained using cryo-electron microscopy. Beyond unveiling the pivotal role of chitinolytic enzymes in the active invasion of a fungus by bacteria, these findings grant unprecedented insight into the fungal cell wall penetration and symbiosis formation.
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Affiliation(s)
- Nadine Moebius
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Zerrin Üzüm
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | | | - Gerald Lackner
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
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Lanubile A, Ferrarini A, Maschietto V, Delledonne M, Marocco A, Bellin D. Functional genomic analysis of constitutive and inducible defense responses to Fusarium verticillioides infection in maize genotypes with contrasting ear rot resistance. BMC Genomics 2014; 15:710. [PMID: 25155950 PMCID: PMC4153945 DOI: 10.1186/1471-2164-15-710] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 08/04/2014] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Fusarium verticillioides causes ear rot in maize (Zea mays L.) and accumulation of mycotoxins, that affect human and animal health. Currently, chemical and agronomic measures to control Fusarium ear rot are not very effective and selection of more resistant genotypes is a desirable strategy to reduce contaminations. A deeper knowledge of molecular events and genetic basis underlying Fusarium ear rot is necessary to speed up progress in breeding for resistance. RESULTS A next-generation RNA-sequencing approach was used for the first time to study transcriptional changes associated with F. verticillioides inoculation in resistant CO441 and susceptible CO354 maize genotypes at 72 hours post inoculation. More than 100 million sequence reads were generated for inoculated and uninoculated control plants and analyzed to measure gene expression levels. Comparison of expression levels between inoculated vs. uninoculated and resistant vs. susceptible transcriptomes revealed a total number of 6,951 differentially expressed genes. Differences in basal gene expression were observed in the uninoculated samples. CO441 genotype showed a higher level of expression of genes distributed over all functional classes, in particular those related to secondary metabolism category. After F. verticillioides inoculation, a similar response was observed in both genotypes, although the magnitude of induction was much greater in the resistant genotype. This response included higher activation of genes involved in pathogen perception, signaling and defense, including WRKY transcription factors and jasmonate/ethylene mediated defense responses. Interestingly, strong differences in expression between the two genotypes were observed in secondary metabolism category: pathways related to shikimate, lignin, flavonoid and terpenoid biosynthesis were strongly represented and induced in the CO441 genotype, indicating that selection to enhance these traits is an additional strategy for improving resistance against F. verticillioides infection. CONCLUSIONS The work demonstrates that the global transcriptional analysis provided an exhaustive view of genes involved in pathogen recognition and signaling, and controlling activities of different TFs, phytohormones and secondary metabolites, that contribute to host resistance against F. verticillioides. This work provides an important source of markers for development of disease resistance maize genotypes and may have relevance to study other pathosystems involving mycotoxin-producing fungi.
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Affiliation(s)
| | | | | | | | - Adriano Marocco
- Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
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Rahman MM, Inoue A, Ojima T. Characterization of a GHF45 cellulase, AkEG21, from the common sea hare Aplysia kurodai. Front Chem 2014; 2:60. [PMID: 25147784 PMCID: PMC4123733 DOI: 10.3389/fchem.2014.00060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
The common sea hare Aplysia kurodai is known to be a good source for the enzymes degrading seaweed polysaccharides. Recently four cellulases, i.e., 95, 66, 45, and 21 kDa enzymes, were isolated from A. kurodai (Tsuji et al., 2013). The former three cellulases were regarded as glycosyl-hydrolase-family 9 (GHF9) enzymes, while the 21 kDa cellulase was suggested to be a GHF45 enzyme. The 21 kDa cellulase was significantly heat stable, and appeared to be advantageous in performing heterogeneous expression and protein-engineering study. In the present study, we determined some enzymatic properties of the 21 kDa cellulase and cloned its cDNA to provide the basis for the protein engineering study of this cellulase. The purified 21 kDa enzyme, termed AkEG21 in the present study, hydrolyzed carboxymethyl cellulose with an optimal pH and temperature at 4.5 and 40°C, respectively. AkEG21 was considerably heat-stable, i.e., it was not inactivated by the incubation at 55°C for 30 min. AkEG21 degraded phosphoric-acid-swollen cellulose producing cellotriose and cellobiose as major end products but hardly degraded oligosaccharides smaller than tetrasaccharide. This indicated that AkEG21 is an endolytic β-1,4-glucanase (EC 3.2.1.4). A cDNA of 1013 bp encoding AkEG21 was amplified by PCR and the amino-acid sequence of 197 residues was deduced. The sequence comprised the initiation Met, the putative signal peptide of 16 residues for secretion and the catalytic domain of 180 residues, which lined from the N-terminus in this order. The sequence of the catalytic domain showed 47–62% amino-acid identities to those of GHF45 cellulases reported in other mollusks. Both the catalytic residues and the N-glycosylation residues known in other GHF45 cellulases were conserved in AkEG21. Phylogenetic analysis for the amino-acid sequences suggested the close relation between AkEG21 and fungal GHF45 cellulases.
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Affiliation(s)
- Mohammad M Rahman
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan ; Department of Fisheries Biology and Genetics, Bangladesh Agricultural University Mymensingh, Bangladesh
| | - Akira Inoue
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan
| | - Takao Ojima
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan
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Wang SD, Guo GS, Li L, Cao LC, Tong L, Ren GH, Liu YH. Identification and characterization of an unusual glycosyltransferase-like enzyme with β-galactosidase activity from a soil metagenomic library. Enzyme Microb Technol 2014; 57:26-35. [DOI: 10.1016/j.enzmictec.2014.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 01/13/2014] [Accepted: 01/16/2014] [Indexed: 11/25/2022]
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[Mechanisms and regulation of enzymatic hydrolysis of cellulose in filamentous fungi: classical cases and new models]. Rev Iberoam Micol 2014; 32:1-12. [PMID: 24607657 DOI: 10.1016/j.riam.2013.10.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 09/25/2013] [Accepted: 10/23/2013] [Indexed: 11/21/2022] Open
Abstract
Cellulose is the most abundant renewable carbon source on earth. However, this polymer structure comprises a physical and chemical barrier for carbon access, which has limited its exploitation. In nature, only a few percentage of microorganisms may degrade this polymer by cellulase expression. Filamentous fungi are one of the most active and efficient groups among these microorganisms. This review describes similarities and differences between cellulase activity mechanisms and regulatory mechanisms controlling gene expression for 3 of the most studied cellulolytic filamentous fungi models: Trichoderma reesei, Aspergillus niger and Aspergillus nidulans, and the recently described model Neurospora crassa. Unlike gene expression mechanisms, it was found that enzymatic activity mechanisms are similar for all the studied models. Understanding the distinctive elements of each system is essential for the development of strategies for the improvement of cellulase production, either by providing the optimum environment (fermentation conditions) or increasing gene expression in these microorganisms by genetic engineering.
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65
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Busi MV, Gomez-Casati DF, Martín M, Barchiesi J, Grisolía MJ, Hedín N, Carrillo JB. Starch Metabolism in Green Plants. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_78-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Luang S, Cho JI, Mahong B, Opassiri R, Akiyama T, Phasai K, Komvongsa J, Sasaki N, Hua YL, Matsuba Y, Ozeki Y, Jeon JS, Cairns JRK. Rice Os9BGlu31 is a transglucosidase with the capacity to equilibrate phenylpropanoid, flavonoid, and phytohormone glycoconjugates. J Biol Chem 2013; 288:10111-10123. [PMID: 23430256 PMCID: PMC3617254 DOI: 10.1074/jbc.m112.423533] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 02/15/2013] [Indexed: 10/07/2023] Open
Abstract
Glycosylation is an important mechanism of controlling the reactivities and bioactivities of plant secondary metabolites and phytohormones. Rice (Oryza sativa) Os9BGlu31 is a glycoside hydrolase family GH1 transglycosidase that acts to transfer glucose between phenolic acids, phytohormones, and flavonoids. The highest activity was observed with the donors feruloyl-glucose, 4-coumaroyl-glucose, and sinapoyl-glucose, which are known to serve as donors in acyl and glucosyl transfer reactions in the vacuole, where Os9BGlu31 is localized. The free acids of these compounds also served as the best acceptors, suggesting that Os9BGlu31 may equilibrate the levels of phenolic acids and carboxylated phytohormones and their glucoconjugates. The Os9BGlu31 gene is most highly expressed in senescing flag leaf and developing seed and is induced in rice seedlings in response to drought stress and treatment with phytohormones, including abscisic acid, ethephon, methyljasmonate, 2,4-dichlorophenoxyacetic acid, and kinetin. Although site-directed mutagenesis of Os9BGlu31 indicated a function for the putative catalytic acid/base (Glu(169)), catalytic nucleophile residues (Glu(387)), and His(386), the wild type enzyme displays an unusual lack of inhibition by mechanism-based inhibitors of GH1 β-glucosidases that utilize a double displacement retaining mechanism.
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Affiliation(s)
- Sukanya Luang
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Jung-Il Cho
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
| | - Bancha Mahong
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
| | - Rodjana Opassiri
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Takashi Akiyama
- National Agricultural Research Center for Hokkaido Region, 1 Hitsujigaoka, Toyohira-ku, Sapporo, Hokkaido 062-8555, Japan
| | - Kannika Phasai
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Juthamath Komvongsa
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Nobuhiro Sasaki
- Department of Biotechnology and Life Science, Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Yan-Ling Hua
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; Center for Scientific and Technological Equipment, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Yuki Matsuba
- Department of Biotechnology and Life Science, Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Yoshihiro Ozeki
- Department of Biotechnology and Life Science, Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Jong-Seong Jeon
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea.
| | - James R Ketudat Cairns
- Institute of Science, Schools of Biochemistry and Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; Laboratory of Biochemistry, Chulabhorn Research Institute, Bangkok 10210, Thailand.
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Basu D, Liang Y, Liu X, Himmeldirk K, Faik A, Kieliszewski M, Held M, Showalter AM. Functional identification of a hydroxyproline-o-galactosyltransferase specific for arabinogalactan protein biosynthesis in Arabidopsis. J Biol Chem 2013; 288:10132-10143. [PMID: 23430255 DOI: 10.1074/jbc.m112.432609] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although plants contain substantial amounts of arabinogalactan proteins (AGPs), the enzymes responsible for AGP glycosylation are largely unknown. Bioinformatics indicated that AGP galactosyltransferases (GALTs) are members of the carbohydrate-active enzyme glycosyltransferase (GT) 31 family (CAZy GT31) involved in N- and O-glycosylation. Six Arabidopsis GT31 members were expressed in Pichia pastoris and tested for enzyme activity. The At4g21060 gene (named AtGALT2) was found to encode activity for adding galactose (Gal) to hydroxyproline (Hyp) in AGP protein backbones. AtGALT2 specifically catalyzed incorporation of [(14)C]Gal from UDP-[(14)C]Gal to Hyp of model substrate acceptors having AGP peptide sequences, consisting of non-contiguous Hyp residues, such as (Ala-Hyp) repetitive units exemplified by chemically synthesized (AO)7 and anhydrous hydrogen fluoride-deglycosylated d(AO)51. Microsomal preparations from Pichia cells expressing AtGALT2 incorporated [(14)C]Gal to (AO)7, and the resulting product co-eluted with (AO)7 by reverse-phase HPLC. Acid hydrolysis of the [(14)C]Gal-(AO)7 product released (14)C-radiolabel as Gal only. Base hydrolysis of the [(14)C]Gal-(AO)7 product released a (14)C-radiolabeled fragment that co-eluted with a Hyp-Gal standard after high performance anion-exchange chromatography fractionation. AtGALT2 is specific for AGPs because substrates lacking AGP peptide sequences did not act as acceptors. Moreover, AtGALT2 uses only UDP-Gal as the substrate donor and requires Mg(2+) or Mn(2+) for high activity. Additional support that AtGALT2 encodes an AGP GALT was provided by two allelic AtGALT2 knock-out mutants, which demonstrated lower GALT activities and reductions in β-Yariv-precipitated AGPs compared with wild type plants. Confocal microscopic analysis of fluorescently tagged AtGALT2 in tobacco epidermal cells indicated that AtGALT2 is probably localized in the endomembrane system consistent with its function.
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Affiliation(s)
- Debarati Basu
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Yan Liang
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Xiao Liu
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Klaus Himmeldirk
- Department of Chemistry and Biochemistry, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Ahmed Faik
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Marcia Kieliszewski
- Department of Chemistry and Biochemistry, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Michael Held
- Department of Chemistry and Biochemistry, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979
| | - Allan M Showalter
- Department of Environmental and Plant Biology, Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701-2979.
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Abstract
Spores of Clostridium difficile play a key role in the dissemination of this important human pathogen, and until recently little has been known of their functional characteristics. Genes encoding six spore coat proteins (cotA, cotB, cotCB, cotD, cotE, and sodA) were disrupted by ClosTron insertional mutagenesis. Mutation of one gene, cotA, presented a major structural defect in spore assembly, with a clear misassembly of the outermost layers of the spore coat. The CotA protein is most probably subject to posttranslational modification and could play a key role in stabilizing the spore coat. Surprisingly, mutation of the other spore coat genes did not affect the integrity of the spore, although for the cotD, cotE, and sodA mutants, enzyme activity was reduced or abolished. This could imply that these enzymatic proteins are located in the exosporium or alternatively that they are structurally redundant. Of the spore coat proteins predicted to carry enzymatic activity, three were confirmed to be enzymes using both in vivo and in vitro methods, the latter using recombinant expressed proteins. These were a manganese catalase, encoded by cotD, a superoxide dismutase (SOD), encoded by sodA, and a bifunctional enzyme with peroxiredoxin and chitinase activity, encoded by cotE. These enzymes being exposed on the spore surface would play a role in coat polymerization and detoxification of H2O2. Two additional proteins, CotF (a tyrosine-rich protein and potential substrate for SodA) and CotG (a putative manganese catalase) were shown to be located at the spore surface.
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69
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Sui XL, Meng FZ, Wang HY, Wei YX, Li RF, Wang ZY, Hu LP, Wang SH, Zhang ZX. Molecular cloning, characteristics and low temperature response of raffinose synthase gene in Cucumis sativus L. JOURNAL OF PLANT PHYSIOLOGY 2012; 169:1883-91. [PMID: 22985990 DOI: 10.1016/j.jplph.2012.07.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 07/30/2012] [Accepted: 07/30/2012] [Indexed: 05/07/2023]
Abstract
Raffinose synthase (RS, EC2.4.1.82) is one of the key enzymes that channels sucrose into the raffinose family oligosaccharides (RFOs) biosynthetic pathway. However, the gene encoding RS is poorly characterized in cucumber (Cucumis sativus L.), which is a typical RFOs-translocating plant species. Here we isolated the gene encoding RS (CsRS) from the leaves of cucumber plants. The complete cDNA of CsRS consisted of 2552 nucleotides with an open reading frame encoding a polypeptide of 784 amino acid residues. Reverse transcription-polymerase chain reaction and RNA hybridization analysis revealed that expression of CsRS was the highest in leaves followed by roots, fruits, and stems. The RS activity was up-regulated and the raffinose content was high in the leaves of transgenic tobacco with over-expression of CsRS, while both the RS activity and the raffinose content decreased in the transgenic cucumber plants with anti-sense expression of CsRS. The expression of CsRS could be induced by low temperature and exogenous phytohormone abscisic acid (ABA). In cucumber growing under low temperature stress, CsRS expression, RS activity and raffinose content increased gradually in the leaves, the fruits, the stems and the roots. The most notable increase was observed in the leaves. Similarly, the expression of CsRS was induced in cucumber leaves and fruits with 200 μM and 150 μM ABA treatments, respectively.
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Affiliation(s)
- Xiao-lei Sui
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
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70
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Valencia A, Alves AP, Siegfried BD. Molecular cloning and functional characterization of an endogenous endoglucanase belonging to GHF45 from the western corn rootworm, Diabrotica virgifera virgifera. Gene 2012; 513:260-7. [PMID: 23137634 DOI: 10.1016/j.gene.2012.10.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 09/14/2012] [Accepted: 10/10/2012] [Indexed: 11/30/2022]
Abstract
A novel insect β-1,4-endoglucanase (DvvENGaseI) gene belonging to the glycoside hydrolase family (GHF) 45 was identified from the western corn rootworm, Diabrotica virgifera virgifera. The cDNA of the DvvENGaseI consisted of a 720 bp open reading frame encoding a 239 amino-acid protein. Analysis of the amino acid sequence revealed that DvvENGaseI exhibits 60% protein sequence identity when compared with an endoglucanase belonging to GHF45 from another beetle, Leptinotarsa decemlineata. Western blot analyses using a polyclonal antiserum developed from a partial peptide sequence revealed that DvvENGaseI expression coincided with body regions corresponding to the fore-, mid- and hindgut, although regions corresponding to the midgut and hindgut were the primary sites for DvvENGaseI expression. Functional analysis of the DvvENGaseI by RNA interference (RNAi) indicated that nearly complete knock-down of gene expression could be obtained by injection of dsRNA based on qRT-PCR and western blot analysis. However, suppression only resulted in slight developmental delays suggesting that this gene may be part of a larger system of cellulose degrading enzymes.
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Affiliation(s)
- Arnubio Valencia
- Departamento de Producción Agropecuaria, Facultad de Ciencias Agropecuarias, Universidad de Caldas, Calle 65#26-10, Manizales, Colombia
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71
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Quinet M, Vromman D, Clippe A, Bertin P, Lequeux H, Dufey I, Lutts S, Lefèvre I. Combined transcriptomic and physiological approaches reveal strong differences between short- and long-term response of rice (Oryza sativa) to iron toxicity. PLANT, CELL & ENVIRONMENT 2012; 35:1837-59. [PMID: 22506799 DOI: 10.1111/j.1365-3040.2012.02521.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ferrous iron toxicity is a mineral disorder frequently occurring under waterlogged soils where rice is cultivated. To decipher the main metabolic pathways involved in rice response to iron excess, seedlings have been exposed to 125 mg L(-1) FeSO(4) for 3 weeks. A combined transcriptomic, biochemical and physiological study has been performed after short-term (3 d) or long-term (3 weeks) exposure to iron in order to elucidate the strategy of stress adaptation with time. Our results showed that short- and long-term exposure involved a very different response in gene expression regarding both the number and function. A larger number of genes were up- or down-regulated after 3 d than after 3 weeks of iron treatment; these changes also occurred in shoot even though no significant difference in iron concentration was recorded. Those modifications in gene expression after 3 d affected not only genes involved in hormonal signalling but also genes involved in C-compound and carbohydrate metabolism, oxygen and electron transfer, oxidative stress, and iron homeostasis and transport. Modification in some gene expression can be followed by modification in corresponding metabolic products and physiological properties, or differed in time for some others, underlying the importance of an integrated study.
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Affiliation(s)
- Muriel Quinet
- Groupe de Recherche en Physiologie Végétale (GRPV), Earth and Life Institute-Agronomy (ELI-A), Université catholique de Louvain, Louvain-la-Neuve, Belgium
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The crystallization and structural analysis of cellulases (and other glycoside hydrolases): strategies and tactics. Methods Enzymol 2012; 510:141-68. [PMID: 22608725 DOI: 10.1016/b978-0-12-415931-0.00008-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The three-dimensional (3-D) structures of cellulases, and other glycoside hydrolases, are a central feature of research in carbohydrate chemistry and biochemistry. 3-D structure is used to inform protein engineering campaigns, both academic and industrial, which are typically used to improve the stability or activity of an enzyme. Examples of classical protein engineering goals include higher thermal stability, reduced metal-ion dependency, detergent and protease resistance, decreased product inhibition, and altered specificity. 3-D structure may also be used to interpret the behavior of enzyme variants that are derived from screening or random mutagenesis approaches, with a view to establishing an iterative design process. In other areas, 3-D structure is used as one of the many tools to probe enzymatic catalysis, typically dovetailing with physical organic chemistry approaches to provide complete reaction mechanisms for enzymes by visualizing catalytic site interactions at different stages of the reaction. Such mechanistic insight is not only fundamentally important, impacting on inhibitor and drug design approaches with ramifications way beyond cellulose hydrolysis, but also provides the framework for the design of enzyme variants to use as biocatalysts for the synthesis of bespoke oligosaccharides. Here we review some of the strategies and tactics that may be applied to the X-ray structure solution of cellulases (and other carbohydrate-active enzymes). The general approach is first to decide why you are doing the work, then to establish correct domain boundaries for truncated constructs (typically the catalytic domain only), and finally to pursue crystallization of pure, homogeneous, and monodisperse protein with appropriate ligand and additive combinations. Cellulase-specific strategies are important for the delineation of domain boundaries, while glycoside hydrolases generally also present challenges and opportunities for the selection and optimization of ligands to both aid crystallization, and also provide structural and mechanistic insight. As the many roles for plant cell wall degrading enzymes increase, so does the need for rapid high-quality structure determination to provide a sound structural foundation for understanding mechanism and specificity, and for future protein engineering strategies.
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73
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Moran-Mirabal JM, Bolewski JC, Walker LP. Thermobifida fuscacellulases exhibit limited surface diffusion on bacterial micro-crystalline cellulose. Biotechnol Bioeng 2012; 110:47-56. [DOI: 10.1002/bit.24604] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 06/02/2012] [Accepted: 07/02/2012] [Indexed: 11/08/2022]
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Cretoiu MS, Kielak AM, Abu Al-Soud W, Sørensen SJ, van Elsas JD. Mining of unexplored habitats for novel chitinases--chiA as a helper gene proxy in metagenomics. Appl Microbiol Biotechnol 2012; 94:1347-58. [PMID: 22526805 PMCID: PMC3353111 DOI: 10.1007/s00253-012-4057-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/26/2012] [Accepted: 03/27/2012] [Indexed: 11/29/2022]
Abstract
The main objective of this study was to assess the abundance and diversity of chitin-degrading microbial communities in ten terrestrial and aquatic habitats in order to provide guidance to the subsequent exploration of such environments for novel chitinolytic enzymes. A combined protocol which encompassed (1) classical overall enzymatic assays, (2) chiA gene abundance measurement by qPCR, (3) chiA gene pyrosequencing, and (4) chiA gene-based PCR-DGGE was used. The chiA gene pyrosequencing is unprecedented, as it is the first massive parallel sequencing of this gene. The data obtained showed the existence across habitats of core bacterial communities responsible for chitin assimilation irrespective of ecosystem origin. Conversely, there were habitat-specific differences. In addition, a suite of sequences were obtained that are as yet unregistered in the chitinase database. In terms of chiA gene abundance and diversity, typical low-abundance/diversity versus high-abundance/diversity habitats was distinguished. From the combined data, we selected chitin-amended agricultural soil, the rhizosphere of the Arctic plant Oxyria digyna and the freshwater sponge Ephydatia fluviatilis as the most promising habitats for subsequent bioexploration. Thus, the screening strategy used is proposed as a guide for further metagenomics-based exploration of the selected habitats.
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Abstract
Glycogen is a branched polymer of glucose that acts as a store of energy in times of nutritional sufficiency for utilization in times of need. Its metabolism has been the subject of extensive investigation and much is known about its regulation by hormones such as insulin, glucagon and adrenaline (epinephrine). There has been debate over the relative importance of allosteric compared with covalent control of the key biosynthetic enzyme, glycogen synthase, as well as the relative importance of glucose entry into cells compared with glycogen synthase regulation in determining glycogen accumulation. Significant new developments in eukaryotic glycogen metabolism over the last decade or so include: (i) three-dimensional structures of the biosynthetic enzymes glycogenin and glycogen synthase, with associated implications for mechanism and control; (ii) analyses of several genetically engineered mice with altered glycogen metabolism that shed light on the mechanism of control; (iii) greater appreciation of the spatial aspects of glycogen metabolism, including more focus on the lysosomal degradation of glycogen; and (iv) glycogen phosphorylation and advances in the study of Lafora disease, which is emerging as a glycogen storage disease.
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76
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Vizoná Liberato M, Cardoso Generoso W, Malagó W, Henrique-Silva F, Polikarpov I. Crystallization and preliminary X-ray diffraction analysis of endoglucanase III from Trichoderma harzianum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:306-9. [PMID: 22442229 PMCID: PMC3310537 DOI: 10.1107/s1744309112000838] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 01/09/2012] [Indexed: 11/06/2023]
Abstract
Endoglucanases are enzymes that hydrolyze cellulose and are important components of the cellulolytic complex. In contrast to other members of the complex, they cleave internal β-1,4-glycosidic bonds in the cellulose polymer, allowing cellulose to be used as an energy source. Since biomass is an important renewable source of energy, the structural and functional characterization of these enzymes is of interest. In this study, endoglucanase III from Trichoderma harzianum was produced in Pichia pastoris and purified. Crystals belonging to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 47.54, b = 55.57, c = 157.3 Å, were obtained by the sitting-drop vapour-diffusion method and an X-ray diffraction data set was collected to 2.07 Å resolution.
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Affiliation(s)
- Marcelo Vizoná Liberato
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, 13566-590 São Carlos-SP, Brazil
| | - Wesley Cardoso Generoso
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Wilson Malagó
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Flávio Henrique-Silva
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, 13566-590 São Carlos-SP, Brazil
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Activity-based metagenomic screening and biochemical characterization of bovine ruminal protozoan glycoside hydrolases. Appl Environ Microbiol 2011; 77:8106-13. [PMID: 21948825 DOI: 10.1128/aem.05925-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rumen, the foregut of herbivorous ruminant animals such as cattle, functions as a bioreactor to process complex plant material. Among the numerous and diverse microbes involved in ruminal digestion are the ruminal protozoans, which are single-celled, ciliated eukaryotic organisms. An activity-based screen was executed to identify genes encoding fibrolytic enzymes present in the metatranscriptome of a bovine ruminal protozoan-enriched cDNA expression library. Of the four novel genes identified, two were characterized in biochemical assays. Our results provide evidence for the effective use of functional metagenomics to retrieve novel enzymes from microbial populations that cannot be maintained in axenic cultures.
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Manzo N, D'Apuzzo E, Coutinho PM, Cutting SM, Henrissat B, Ricca E. Carbohydrate-active enzymes from pigmented Bacilli: a genomic approach to assess carbohydrate utilization and degradation. BMC Microbiol 2011; 11:198. [PMID: 21892951 PMCID: PMC3178493 DOI: 10.1186/1471-2180-11-198] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 09/05/2011] [Indexed: 12/02/2022] Open
Abstract
Background Spore-forming Bacilli are Gram-positive bacteria commonly found in a variety of natural habitats, including soil, water and the gastro-intestinal (GI)-tract of animals. Isolates of various Bacillus species produce pigments, mostly carotenoids, with a putative protective role against UV irradiation and oxygen-reactive forms. Results We report the annotation of carbohydrate active enzymes (CAZymes) of two pigmented Bacilli isolated from the human GI-tract and belonging to the Bacillus indicus and B. firmus species. A high number of glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) were found in both isolates. A detailed analysis of CAZyme families, was performed and supported by growth data. Carbohydrates able to support growth as the sole carbon source negatively effected carotenoid formation in rich medium, suggesting that a catabolite repression-like mechanism controls carotenoid biosynthesis in both Bacilli. Experimental results on biofilm formation confirmed genomic data on the potentials of B. indicus HU36 to produce a levan-based biofilm, while mucin-binding and -degradation experiments supported genomic data suggesting the ability of both Bacilli to degrade mammalian glycans. Conclusions CAZy analyses of the genomes of the two pigmented Bacilli, compared to other Bacillus species and validated by experimental data on carbohydrate utilization, biofilm formation and mucin degradation, suggests that the two pigmented Bacilli are adapted to the intestinal environment and are suited to grow in and colonize the human gut.
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Affiliation(s)
- Nicola Manzo
- Department of Structural and Functional Biology, Federico II University of Naples, MSA, via Cinthia 4, 80126 Napoli, Italy
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79
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Catalytic properties of the Gas family β-(1,3)-glucanosyltransferases active in fungal cell-wall biogenesis as determined by a novel fluorescent assay. Biochem J 2011; 438:275-82. [DOI: 10.1042/bj20110405] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BGTs [β-(1,3)-glucanosyltransglycosylases; EC 2.4.1.-] of the GH72 (family 72 of glycosylhydrolases) are GPI (glycosylphosphatidylinositol)-anchored proteins that play an important role in the biogenesis of fungal cell walls. They randomly cleave glycosidic linkages in β-(1,3)-glucan chains and ligate the polysaccharide portions containing newly formed reducing ends to C3(OH) at non-reducing ends of other β-(1,3)-glucan molecules. We have developed a sensitive fluorescence-based method for the assay of transglycosylating activity of GH72 enzymes. In the new assay, laminarin [β-(1,3)-glucan] is used as the glucanosyl donor and LamOS (laminarioligosaccharides) fluorescently labelled with SR (sulforhodamine) serve as the acceptors. The new fluorescent assay was employed for partial biochemical characterization of the heterologously expressed Gas family proteins from the yeast Saccharomyces cerevisiae. All the Gas enzymes specifically used laminarin as the glucanosyl donor and a SR–LamOS of DP (degree of polymerization) ≥5 as the acceptors. Gas proteins expressed in distinct stages of the yeast life cycle showed differences in their pH optima. Gas1p and Gas5p, which are expressed during vegetative growth, had the highest activity at pH 4.5 and 3.5 respectively, whereas the sporulation-specific Gas2p and Gas4p were most active between pH 5 and 6. The novel fluorescent assay provides a suitable tool for the screening of potential glucanosyltransferases or their inhibitors.
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80
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Phr1p, a glycosylphosphatidylinsitol-anchored β(1,3)-glucanosyltransferase critical for hyphal wall formation, localizes to the apical growth sites and septa in Candida albicans. Fungal Genet Biol 2011; 48:793-805. [DOI: 10.1016/j.fgb.2011.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 05/02/2011] [Accepted: 05/03/2011] [Indexed: 01/19/2023]
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81
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Rosewarne CP, Pope PB, Denman SE, McSweeney CS, O'Cuiv P, Morrison M. High-yield and phylogenetically robust methods of DNA recovery for analysis of microbial biofilms adherent to plant biomass in the herbivore gut. MICROBIAL ECOLOGY 2011; 61:448-54. [PMID: 20838785 DOI: 10.1007/s00248-010-9745-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2010] [Accepted: 09/01/2010] [Indexed: 05/23/2023]
Abstract
Recent studies have shown the microbial biofilms adherent to plant biomass in the gastrointestinal tracts of humans and other herbivores are quite different to planktonic populations. If these biofilm communities are to be properly characterized by metagenomics methods, then the microbial desorption methods used must ensure the phylogenetic diversity and genetic potential recovered is biologically valid. To that end, we describe here two different methods for desorbing microbes tightly adherent to plant biomass; and used PCR-DGGE analyses of the Bacteria and Archaea rrs genes to show both these desorption methods were effective in recovering the adherent microbial biofilm with no apparent biases in microbe recovery. We also present a derivation of the "repeated bead beating and column (RBB+C) purification" method of DNA extraction that results in the recovery of high molecular weight DNA. These DNA samples can be fragmented and size fractionated by sucrose density gradient centrifugation, bypassing the use of gel-plug lysis and pulsed-field gel electrophoresis separation of DNA for metagenomic library constructions.
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Affiliation(s)
- Carly P Rosewarne
- Commonwealth Scientific and Industrial Research Organisation, Division of Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, QLD 4067, Australia
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82
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Abstract
Carbohydrate-active enzymes face huge substrate diversity in a highly selective manner using only a limited number of available folds. They are therefore subjected to multiple divergent and convergent evolutionary events. This and their frequent modularity render their functional annotation in genomes difficult in a number of cases. In the present paper, a classification of polysaccharide lyases (the enzymes that cleave polysaccharides using an elimination instead of a hydrolytic mechanism) is shown thoroughly for the first time. Based on the analysis of a large panel of experimentally characterized polysaccharide lyases, we examined the correlation of various enzyme properties with the three levels of the classification: fold, family and subfamily. The resulting hierarchical classification, which should help annotate relevant genes in genomic efforts, is available and constantly updated at the Carbohydrate-Active Enzymes Database (http://www.cazy.org).
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83
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Kongsaeree PT, Ratananikom K, Choengpanya K, Tongtubtim N, Sujiwattanarat P, Porncharoennop C, Onpium A, Svasti J. Substrate specificity in hydrolysis and transglucosylation by family 1 β-glucosidases from cassava and Thai rosewood. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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84
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Cheroni S, Formantici C, Galante YM. Depolymerization of carboxymethylcellulose in a hydro-alcoholic medium by a mono-component endocellulase. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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85
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Zhou C, Yin Y, Dam P, Xu Y. Identification of novel proteins involved in plant cell-wall synthesis based on protein-protein interaction data. J Proteome Res 2010; 9:5025-37. [PMID: 20687615 DOI: 10.1021/pr100249c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The plant cell wall is mainly composed of polysaccharides, representing the richest source of biomass for future biofuel production. Currently, the majority of the cell-wall synthesis-related (CWSR) proteins are unknown even for model plant Arabidopsis thaliana. We report a computational framework for predicting CWSR proteins based on protein-protein interaction (PPI) data and known CWSR proteins. We predict a protein to be a CWSR protein if it interacts with known CWSR proteins (seeds) with high statistical significance. Using this technique, we predicted 100 candidate CWSR proteins in Arabidopsis thaliana, 8 of which were experimentally confirmed by previous reports. Forty-two candidates have either independent supporting evidence or strong functional relevance to cell-wall synthesis and, hence, are considered as the most reliable predictions. For 33 of the predicted CWSR proteins, we have predicted their detailed functional roles in CWS, based on analyses of their domain architectures, phylogeny, and current functional annotation in conjunction with a literature search. We present the constructed PPIs covering all the known and predicted CWSR proteins at http://csbl.bmb.uga.edu/∼zhouchan/CellWallProtein/. The 42 most reliable candidates provide useful targets to experimentalists for further investigation, and the PPI data constructed in this work provides new information for cell-wall research.
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Affiliation(s)
- Chan Zhou
- Computational Systems Biology Laboratory, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, Georgia 30602, USA
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86
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87
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Gilbert HJ. The biochemistry and structural biology of plant cell wall deconstruction. PLANT PHYSIOLOGY 2010; 153:444-55. [PMID: 20406913 PMCID: PMC2879781 DOI: 10.1104/pp.110.156646] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 04/17/2010] [Indexed: 05/18/2023]
Affiliation(s)
- Harry J Gilbert
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
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Gunasekara S, Vrielink A, Stubbs KA. Preliminary studies into the inhibition of the cholesterol α-glucosyltransferase from Helicobacter pylori using azasugars. Carbohydr Res 2010; 345:960-4. [PMID: 20307874 DOI: 10.1016/j.carres.2010.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/17/2010] [Accepted: 03/01/2010] [Indexed: 11/26/2022]
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89
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Dwevedi A, Kayastha AM. A beta-galactosidase from pea seeds (PsBGAL): purification, stabilization, catalytic energetics, conformational heterogeneity, and its significance. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:7086-96. [PMID: 19552429 DOI: 10.1021/jf900874p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A basic glycosylated beta-galactosidase (PsBGAL) has been purified from pea seeds by 910-fold with a specific activity of 77.33 mumoL min(-1) mg(-1) protein. The purified enzyme is an electrophoretically homogeneous protein consisting of a single protein band with an apparent M(r) of 55 kDa, while the deglycosylated enzyme has a M(r) of 54.2 kDa on SDS-PAGE under reducing conditions. According to MALDI-TOF measurements of the 55 kDa band, the enzyme showed a homology with BGAL from other sources present in the SWISS-PROT database, while it showed no resemblance to any lectin. The N-terminal sequence of PsBGAL was determined as TIECK and showed a resemblance to BGAL from Arabidopsis thaliana (Q93Z24). The enzyme showed an unique property of multiple banding patterns on SDS-PAGE at 20 mA current, with tryptic digests of all bands having similar m/z values (using MALDI-TOF) while it showed only a single band at 10 mA current. PsBGAL is effectively compartmentalized during seed maturation inside vacuoles (pH approximately 5). The enzyme is capable of hydrolyzing pea seed xyloglucan, and it may be involved in modifying the cell wall architecture during seedling growth and development. The enzyme has a protonated carboxyl group at its active site as observed by ionization constant, thermodynamics, and chemical modification studies.
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Affiliation(s)
- Alka Dwevedi
- School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi, UP-221005, India
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90
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Directed evolution of endoglucanase III (Cel12A) from Trichoderma reesei. Appl Microbiol Biotechnol 2009; 83:649-57. [DOI: 10.1007/s00253-009-1901-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 01/22/2009] [Accepted: 01/25/2009] [Indexed: 12/01/2022]
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91
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Vieira DS, Degrève L, Ward RJ. Characterization of temperature dependent and substrate-binding cleft movements in Bacillus circulans family 11 xylanase: a molecular dynamics investigation. Biochim Biophys Acta Gen Subj 2009; 1790:1301-6. [PMID: 19409448 DOI: 10.1016/j.bbagen.2009.04.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 04/14/2009] [Accepted: 04/23/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND Xylanases (EC 3.2.1.8) hydrolyze xylan, one of the most abundant plant polysaccharides found in nature, and have many potential applications in biotechnology. METHODS Molecular dynamics simulations were used to investigate the effects of temperature between 298 to 338 K and xylobiose binding on residues located in the substrate-binding cleft of the family 11 xylanase from Bacillus circulans (BcX). RESULTS In the absence of xylobiose the BcX exhibits temperature dependent movement of the thumb region which adopts an open conformation exposing the active site at the optimum catalytic temperature (328 K). In the presence of substrate, the thumb region restricts access to the active site at all temperatures, and this conformation is maintained by substrate/protein hydrogen bonds involving active site residues, including hydrogen bonds between Tyr69 and the 2' hydroxyl group of the substrate. Substrate access to the active site is regulated by temperature dependent motions that are restricted to the thumb region, and the BcX/substrate complex is stabilized by extensive intermolecular hydrogen bonding with residues in the active site. GENERAL SIGNIFICANCE These results call for a revision of both the "hinge-bending" model for the activity of group 11 xylanases, and the role of Tyr69 in the catalytic mechanism.
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Affiliation(s)
- Davi Serradella Vieira
- Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto--Universidade de São Paulo Ribeirão Preto, SP, Brazil.
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92
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Takahashi J, Rudsander UJ, Hedenström M, Banasiak A, Harholt J, Amelot N, Immerzeel P, Ryden P, Endo S, Ibatullin FM, Brumer H, del Campillo E, Master ER, Vibe Scheller H, Sundberg B, Teeri TT, Mellerowicz EJ. KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems. ACTA ACUST UNITED AC 2009; 50:1099-115. [DOI: 10.1093/pcp/pcp062] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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93
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Michel G, Barbeyron T, Kloareg B, Czjzek M. The family 6 carbohydrate-binding modules have coevolved with their appended catalytic modules toward similar substrate specificity. Glycobiology 2009; 19:615-23. [PMID: 19240276 DOI: 10.1093/glycob/cwp028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The survey of carbohydrate active enzymes in genomic data uncovered the modular architecture of most of these proteins. Many of the additional modules associated with catalytic modules tightly bind carbohydrates. The primary role of these carbohydrate-binding modules (CBMs) is to enhance the enzymatic activity of the ensemble by bringing their appended catalytic module(s) in intimate contact with their substrates. Biochemical and biophysical approaches have unraveled the subtle interplay of the modules and the structural basis for their ligand specificities, but little attention has been paid to the evolutionary mechanisms leading to the appearance of modular architecture in carbohydrate active enzymes. Focusing on the promiscuous family CBM6 modules, we investigated the evolution of substrate specificities in parallel to that of their respectively appended catalytic modules. An extensive phylogenetic analysis of family CBM6 modules indicates that these noncatalytic modules have diverged into clades which coincide with their substrate selectivity. These data as well as the remarkable congruence of the phylogenetic trees inferred from CBM6s on the one hand and their associated catalytic modules on the other hand show that CBM6s and their associated glycoside hydrolases have coevolved to acquire the same substrate specificity. We also propose an evolutionary scenario explaining the emergence of the modular agarases, by which existent alpha-agarases acquired their agar-binding CBM6 module through a lateral transfer from pre-existing beta-agarases. Altogether, this observed coevolution between CBM6s and their catalytic modules will facilitate the prediction of the substrate specificity of uncharacterized CBM6 modules present in genomic data.
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Affiliation(s)
- Gurvan Michel
- UPMC University Paris 06, 3CNRS, UMR 7139 Marine Plants and Biomolecules, Station Biologique de Roscoff, Roscoff, Bretagne, France.
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94
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Ishida T, Fushinobu S, Kawai R, Kitaoka M, Igarashi K, Samejima M. Crystal structure of glycoside hydrolase family 55 {beta}-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J Biol Chem 2009; 284:10100-9. [PMID: 19193645 DOI: 10.1074/jbc.m808122200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Glycoside hydrolase family 55 consists of beta-1,3-glucanases mainly from filamentous fungi. A beta-1,3-glucanase (Lam55A) from the Basidiomycete Phanerochaete chrysosporium hydrolyzes beta-1,3-glucans in the exo-mode with inversion of anomeric configuration and produces gentiobiose in addition to glucose from beta-1,3/1,6-glucans. Here we report the crystal structure of Lam55A, establishing the three-dimensional structure of a member of glycoside hydrolase 55 for the first time. Lam55A has two beta-helical domains in a single polypeptide chain. These two domains are separated by a long linker region but are positioned side by side, and the overall structure resembles a rib cage. In the complex, a gluconolactone molecule is bound at the bottom of a pocket between the two beta-helical domains. Based on the position of the gluconolactone molecule, Glu-633 appears to be the catalytic acid, whereas the catalytic base residue could not be identified. The substrate binding pocket appears to be able to accept a gentiobiose unit near the cleavage site, and a long cleft runs from the pocket, in accordance with the activity of this enzyme toward various beta-1,3-glucan oligosaccharides. In conclusion, we provide important features of the substrate-binding site at the interface of the two beta-helical domains, demonstrating an unexpected variety of carbohydrate binding modes.
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Affiliation(s)
- Takuya Ishida
- Departments of Biomaterials Sciences and Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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95
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Zhou Y, Li S, Qian Q, Zeng D, Zhang M, Guo L, Liu X, Zhang B, Deng L, Liu X, Luo G, Wang X, Li J. BC10, a DUF266-containing and Golgi-located type II membrane protein, is required for cell-wall biosynthesis in rice (Oryza sativa L.). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:446-62. [PMID: 18939965 DOI: 10.1111/j.1365-313x.2008.03703.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Glycosyltransferases (GTs) are one of the largest enzyme groups required for the synthesis of complex wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most GTs in cell-wall biosynthesis and assembly have remained elusive. We report here the isolation and in-depth characterization of a brittle rice mutant, brittle culm 10 (bc10). bc10 plants show pleiotropic phenotypes, including brittleness of the plant body and retarded growth. The BC10 gene was cloned through a map-based approach, and encodes a Golgi-located type II membrane protein that contains a domain designated as 'domain of unknown function 266' (DUF266) and represents a multiple gene family in rice. BC10 has low sequence similarity with the domain to a core 2 beta-1,6-N-acetylglucosaminyltransferase (C2GnT), and its in vitro enzymatic activity suggests that it functions as a glycosyltransferase. Monosaccharide analysis of total and fractioned wall residues revealed that bc10 showed impaired cellulose biosynthesis. Immunolocalization and isolation of arabinogalactan proteins (AGPs) in the wild-type and bc10 showed that the level of AGPs in the mutant is significantly affected. BC10 is mainly expressed in the developing sclerenchyma and vascular bundle cells, and its deficiency causes a reduction in the levels of cellulose and AGPs, leading to inferior mechanical properties.
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Affiliation(s)
- Yihua Zhou
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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96
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Comparative Evolutionary Histories of Fungal Chitinases. Evol Biol 2009. [DOI: 10.1007/978-3-642-00952-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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97
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Insights into the role of the (alpha+beta) insertion in the TIM-barrel catalytic domain, regarding the stability and the enzymatic activity of chitinase A from Serratia marcescens. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:23-31. [PMID: 18973833 DOI: 10.1016/j.bbapap.2008.09.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 09/16/2008] [Accepted: 09/17/2008] [Indexed: 11/20/2022]
Abstract
Chitinase A (ChiA) from Serratia marcescens is a mesophilic enzyme with high catalytic activity and high stability. The crystal structure of ChiA has revealed a TIM-barrel fold of the catalytic domain, an (alpha+beta) insertion between the B7 beta-strand and A7 alpha-helix of the TIM-barrel, an FnIII domain at the N-terminus of the molecule and a hinge region that connects the latter to the catalytic domain. In this study, the role of the (alpha+beta) domain on the stability, catalytic activity and specificity of the enzyme was investigated by deleting this domain and studying the enzymatic and structural properties of the resulting truncated enzyme. The obtained data clearly show that by removing the (alpha+beta) domain, the thermal stability of the enzyme is substantially reduced, with an apparent T(m) of 42.0+/-1.0 degrees C, compared to the apparent T(m) of 58.1+/-1.0 degrees C of ChiA at pH 9.0. The specific activity of ChiADelta(alpha+beta) was substantially decreased, the pH optimum was shifted from 6.5 to 5.0 and the substrate and product specificities were altered.
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98
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Blöchl A, Peterbauer T, Hofmann J, Richter A. Enzymatic breakdown of raffinose oligosaccharides in pea seeds. PLANTA 2008; 228:99-110. [PMID: 18335235 DOI: 10.1007/s00425-008-0722-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 02/26/2008] [Indexed: 05/26/2023]
Abstract
Both alkaline and acidic alpha-galactosidases (alpha-D: -galactoside galactohydrolases, E.C.3.2.1.22) isolated from various plant species have been described, although little is known about their co-occurrence and functions in germinating seeds. Here, we report on the isolation of two cDNAs, encoding for alpha-galactosidases from maturing and germinating seeds of Pisum sativum. One was identified as a member of the acidic alpha-galactosidase of the family 27 glycosyl hydrolase cluster and the other as a member of the family of alkaline alpha-galactosidases, which are highly homologous to seed imbibition proteins (SIPs). PsGAL1 transcripts, encoding for the ACIDIC alpha-GALACTOSIDASE, were predominately expressed during seed maturation and acidic enzyme activities were already present in dry seeds, showing little changes during seed germination. Compartmentation studies revealed that acidic alpha-galactosidases were located in protein storage vacuoles (PSVs). PsAGA1, encoding for the ALKALINE alpha-GALACTOSIDASE, was only expressed after radicle protrusion, when about 50% of RFOs have already been broken down. RFO breakdown was markedly decreased when the translation of the alkaline enzyme was inhibited, providing evidence that PsAGA1 indeed functioned in RFO degradation. Based on these data, we present an integrated model of RFO breakdown by two sequentially active alpha-galactosidases in pea seeds.
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Affiliation(s)
- Andreas Blöchl
- Department of Chemical Ecology and Ecosystem Research, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
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Karlsson M, Stenlid J. Comparative evolutionary histories of the fungal chitinase gene family reveal non-random size expansions and contractions due to adaptive natural selection. Evol Bioinform Online 2008; 4:47-60. [PMID: 19204807 PMCID: PMC2614207 DOI: 10.4137/ebo.s604] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Gene duplication and loss play an important role in the evolution of novel functions and for shaping an organism's gene content. Recently, it was suggested that stress-related genes frequently are exposed to duplications and losses, while growth-related genes show selection against change in copy number. The fungal chitinase gene family constitutes an interesting case study of gene duplication and loss, as their biological roles include growth and development as well as more stress-responsive functions. We used genome sequence data to analyze the size of the chitinase gene family in different fungal taxa, which range from 1 in Batrachochytrium dendrobatidis and Schizosaccharomyces pombe to 20 in Hypocrea jecorina and Emericella nidulans, and to infer their phylogenetic relationships. Novel chitinase subgroups are identified and their phylogenetic relationships with previously known chitinases are discussed. We also employ a stochastic birth and death model to show that the fungal chitinase gene family indeed evolves non-randomly, and we identify six fungal lineages where larger-than-expected expansions (Pezizomycotina, H. jecorina, Gibberella zeae, Uncinocarpus reesii, E. nidulans and Rhizopus oryzae), and two contractions (Coccidioides immitis and S. pombe) potentially indicate the action of adaptive natural selection. The results indicate that antagonistic fungal-fungal interactions are an important process for soil borne ascomycetes, but not for fungal species that are pathogenic in humans. Unicellular growth is correlated with a reduction of chitinase gene copy numbers which emphasizes the requirement of the combined action of several chitinases for filamentous growth.
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Affiliation(s)
- Magnus Karlsson
- Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, P.O. 7026, SE-75007, Uppsala, Sweden.
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100
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Ruller R, Deliberto L, Ferreira TL, Ward RJ. Thermostable variants of the recombinant xylanase a from Bacillus subtilis produced by directed evolution show reduced heat capacity changes. Proteins 2007; 70:1280-93. [PMID: 17876824 DOI: 10.1002/prot.21617] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Directed evolution techniques have been used to improve the thermal stability of the xylanase A from Bacillus subtilis (XylA). Two generations of random mutant libraries generated by error prone PCR coupled with a single generation of DNA shuffling produced a series of mutant proteins with increasing thermostability. The most Thermostable XylA variant from the third generation contained four mutations Q7H, G13R, S22P, and S179C that showed an increase in melting temperature of 20 degrees C. The thermodynamic properties of a representative subset of nine XylA variants showing a range of thermostabilities were measured by thermal denaturation as monitored by the change in the far ultraviolet circular dichroism signal. Analysis of the data from these thermostable variants demonstrated a correlation between the decrease in the heat capacity change (deltaC(p)) with an increase in the midpoint of the transition temperature (T(m)) on transition from the native to the unfolded state. This result could not be interpreted within the context of the changes in accessible surface area of the protein on transition from the native to unfolded states. Since all the mutations are located at the surface of the protein, these results suggest that an explanation of the decrease in deltaC(p) should include effects arising from the protein/solvent interface.
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Affiliation(s)
- Roberto Ruller
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, FMRP-USP, Ribeirão Preto-SP, Universidade de São Paulo, São Paulo, Brazil
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