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de Araújo EA, Cortez AA, Pellegrini VDOA, Vacilotto MM, Cruz AF, Batista PR, Polikarpov I. Molecular mechanism of cellulose depolymerization by the two-domain BlCel9A enzyme from the glycoside hydrolase family 9. Carbohydr Polym 2024; 329:121739. [PMID: 38286536 DOI: 10.1016/j.carbpol.2023.121739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 12/20/2023] [Accepted: 12/23/2023] [Indexed: 01/31/2024]
Abstract
Carbohydrate-active enzymes from the glycoside hydrolase family 9 (GH9) play a key role in processing lignocellulosic biomass. Although the structural features of some GH9 enzymes are known, the molecular mechanisms that drive their interactions with cellulosic substrates remain unclear. To investigate the molecular mechanisms that the two-domain Bacillus licheniformis BlCel9A enzyme utilizes to depolymerize cellulosic substrates, we used a combination of biochemical assays, X-ray crystallography, small-angle X-ray scattering, and molecular dynamics simulations. The results reveal that BlCel9A breaks down cellulosic substrates, releasing cellobiose and glucose as the major products, but is highly inefficient in cleaving oligosaccharides shorter than cellotetraose. In addition, fungal lytic polysaccharide oxygenase (LPMO) TtLPMO9H enhances depolymerization of crystalline cellulose by BlCel9A, while exhibiting minimal impact on amorphous cellulose. The crystal structures of BlCel9A in both apo form and bound to cellotriose and cellohexaose were elucidated, unveiling the interactions of BlCel9A with the ligands and their contribution to substrate binding and products release. MD simulation analysis reveals that BlCel9A exhibits higher interdomain flexibility under acidic conditions, and SAXS experiments indicate that the enzyme flexibility is induced by pH and/or temperature. Our findings provide new insights into BlCel9A substrate specificity and binding, and synergy with the LPMOs.
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Affiliation(s)
- Evandro Ares de Araújo
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Giuseppe Maximo Scolfaro, 10000, Campinas, SP 13083-970, Brazil; Sao Carlos Institute of Physics, University of Sao Paulo, Av. Trabalhador Sao Carlense, 400, Sao Carlos, SP 13566-590, Brazil
| | - Anelyse Abreu Cortez
- Sao Carlos Institute of Physics, University of Sao Paulo, Av. Trabalhador Sao Carlense, 400, Sao Carlos, SP 13566-590, Brazil
| | | | - Milena Moreira Vacilotto
- Sao Carlos Institute of Physics, University of Sao Paulo, Av. Trabalhador Sao Carlense, 400, Sao Carlos, SP 13566-590, Brazil
| | - Amanda Freitas Cruz
- Sao Carlos Institute of Physics, University of Sao Paulo, Av. Trabalhador Sao Carlense, 400, Sao Carlos, SP 13566-590, Brazil
| | - Paulo Ricardo Batista
- Oswaldo Cruz Foundation, Scientific Computing Programme, Av. Brasil, 4365, Rio de Janeiro, RJ 21040-900, Brazil
| | - Igor Polikarpov
- Sao Carlos Institute of Physics, University of Sao Paulo, Av. Trabalhador Sao Carlense, 400, Sao Carlos, SP 13566-590, Brazil.
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Abdel Wahab WA, Mostafa FA, Ahmed SA, Saleh SAA. Statistical optimization of enzyme cocktail production using Jew's mallow stalks residues by a new isolate Aspergillus flavus B2 via statistical strategy and enzymes characterization. J Biotechnol 2023; 367:89-97. [PMID: 37028558 DOI: 10.1016/j.jbiotec.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/25/2023] [Accepted: 04/04/2023] [Indexed: 04/09/2023]
Abstract
This study investigates the production of the enzyme cocktail by the isolated fungi Aspergillus flavus B2 (GenBank accession number OL655454) using agricultural and industrial (AI) residues as the sole substrate. Of all the AI residues tested, Jew's mallow stalk was the best inducer substrate for enzyme cocktail production without adding any nutrients. Statistical optimization using Response Surface Methodology enhanced the production by 5.45, 5.20, and 3.34-fold, respectively for pectinase, xylanase, and CMCase. Optimum temperature, activation energy (Ea), and activation energy for denaturation (Ed) were determined. Michaelis constant (Km) for CMCase, xylanase, and pectinase enzyme was 1.82, 1.23, and 1.05mg/mL, respectively. Maximum reaction rate (Vmax) was 4.67, 5.29, and 17.13U/mL, respectively for CMCase, xylanase, and pectinase. Thermal stability revealed that pectinase, CMCase, and xylanase enzymes retained 64.7, 61.8, and 53.2% residual activities after incubation for 1h at 50 °C. Half-life time (t0.5) of pectinase, CMCase, and xylanase at 50 °C were 189.38, 129.8, and 127.89min, respectively. Thermodynamics of the produced enzymes enthalpy (ΔH⁎d), free energy (ΔG⁎d), and entropy (ΔS⁎d) were determined at 40, 50, and 60°C. In the presence of EDTA (5mM), CMCase, xylanase, and pectinase retained 69.5, 66.2, and 41.2%, respectively of their activity. This work is significant for the valorization of AI residues and the production of value-added products.
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Affiliation(s)
- Walaa A Abdel Wahab
- Chemistry of Natural and Microbial Products Department National Research Centre, Dokki, Cairo, Egypt, 12622.
| | - Faten A Mostafa
- Chemistry of Natural and Microbial Products Department National Research Centre, Dokki, Cairo, Egypt, 12622.
| | - Samia A Ahmed
- Chemistry of Natural and Microbial Products Department National Research Centre, Dokki, Cairo, Egypt, 12622.
| | - Shireen A A Saleh
- Chemistry of Natural and Microbial Products Department National Research Centre, Dokki, Cairo, Egypt, 12622.
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Araújo EA, Dias AHS, Kadowaki MAS, Piyadov V, Pellegrini VOA, Urio MB, Ramos LP, Skaf MS, Polikarpov I. Impact of cellulose properties on enzymatic degradation by bacterial GH48 enzymes: Structural and mechanistic insights from processive Bacillus licheniformis Cel48B cellulase. Carbohydr Polym 2021; 264:118059. [PMID: 33910709 DOI: 10.1016/j.carbpol.2021.118059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 11/29/2022]
Abstract
Processive cellulases are highly efficient molecular engines involved in the cellulose breakdown process. However, the mechanism that processive bacterial enzymes utilize to recruit and retain cellulose strands in the catalytic site remains poorly understood. Here, integrated enzymatic assays, protein crystallography and computational approaches were combined to study the enzymatic properties of the processive BlCel48B cellulase from Bacillus licheniformis. Hydrolytic efficiency, substrate binding affinity, cleavage patterns, and the apparent processivity of bacterial BlCel48B are significantly impacted by the cellulose size and its surface morphology. BlCel48B crystallographic structure was solved with ligands spanning -5 to -2 and +1 to +2 subsites. Statistical coupling analysis and molecular dynamics show that co-evolved residues on active site are critical for stabilizing ligands in the catalytic tunnel. Our results provide mechanistic insights into BlCel48B molecular-level determinants of activity, substrate binding, and processivity on insoluble cellulose, thus shedding light on structure-activity correlations of GH48 family members in general.
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Affiliation(s)
- Evandro A Araújo
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13560-970, São Paulo, Brazil; Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials, Campinas 13083-970, São Paulo, Brazil
| | - Artur Hermano Sampaio Dias
- Institute of Chemistry and Center for Computer in Engineering and Sciences, University of Campinas (UNICAMP), Campinas 13084-862, São Paulo, Brazil
| | - Marco A S Kadowaki
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13560-970, São Paulo, Brazil
| | - Vasily Piyadov
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13560-970, São Paulo, Brazil
| | - Vanessa O A Pellegrini
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13560-970, São Paulo, Brazil
| | - Mateus B Urio
- Graduate Programs in Bioenergy, Chemistry and Chemical Engineering, Federal University of Paraná (UFPR), Curitiba 81531-980, Paraná, Brazil
| | - Luiz P Ramos
- Graduate Programs in Bioenergy, Chemistry and Chemical Engineering, Federal University of Paraná (UFPR), Curitiba 81531-980, Paraná, Brazil
| | - Munir S Skaf
- Institute of Chemistry and Center for Computer in Engineering and Sciences, University of Campinas (UNICAMP), Campinas 13084-862, São Paulo, Brazil
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13560-970, São Paulo, Brazil.
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Lopes DCB, Carraro CB, Silva RN, de Paula RG. Molecular Characterization of Xyloglucanase cel74a from Trichoderma reesei. Int J Mol Sci 2021; 22:ijms22094545. [PMID: 33925273 PMCID: PMC8123685 DOI: 10.3390/ijms22094545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is used on an industrial scale to produce enzymes of biotechnological interest. This fungus has a complex cellulolytic system involved in the degradation of lignocellulosic biomass. However, several aspects related to the regulation of the expression of holocellulolytic genes and the production of cellulases by this fungus are still understood. METHODS Here, we constructed a null mutant strain for the xyloglucanase cel74a gene and performed the characterization of the Δcel74a strain to evaluate the genetic regulation of the holocellulases during sugarcane bagasse (SCB) cultivation. RESULTS Our results demonstrate that the deletion of xyloglucanase cel74a may impact the regulation of holocellulase expression during SCB cultivation. The expression of cellulases cel7a, cel7b, and cel6a was reduced in Δcel74a strain, while the hemicellulases xyn1 and xyn2 were increased in the presence of SCB. The cel74a mutation also affected the xyloglucan hydrolysis patterns. In addition, CEL74A activity was modulated in the presence of calcium, suggesting that this ion may be required for efficient degradation of xyloglucan. CONCLUSIONS CEL74A affects the regulation of holocellulolytic genes and the efficient degradation of SCB in T. reesei. This data makes a significant contribution to our understanding of the carbon utilization of fungal strains as a whole.
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Affiliation(s)
- Douglas Christian Borges Lopes
- Molecular Biotechnology Laboratory, Department of Biochemistry and Immunology, Ribeirao Preto Medical School (FMRP), University of Sao Paulo, Ribeirao Preto 14049-900, SP, Brazil; (D.C.B.L.); (C.B.C.); (R.G.d.P.)
| | - Cláudia Batista Carraro
- Molecular Biotechnology Laboratory, Department of Biochemistry and Immunology, Ribeirao Preto Medical School (FMRP), University of Sao Paulo, Ribeirao Preto 14049-900, SP, Brazil; (D.C.B.L.); (C.B.C.); (R.G.d.P.)
| | - Roberto Nascimento Silva
- Molecular Biotechnology Laboratory, Department of Biochemistry and Immunology, Ribeirao Preto Medical School (FMRP), University of Sao Paulo, Ribeirao Preto 14049-900, SP, Brazil; (D.C.B.L.); (C.B.C.); (R.G.d.P.)
- Correspondence:
| | - Renato Graciano de Paula
- Molecular Biotechnology Laboratory, Department of Biochemistry and Immunology, Ribeirao Preto Medical School (FMRP), University of Sao Paulo, Ribeirao Preto 14049-900, SP, Brazil; (D.C.B.L.); (C.B.C.); (R.G.d.P.)
- Department of Physiological Sciences, Health Sciences Centre, Federal University of Espirito Santo, Vitoria 29047-105, ES, Brazil
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Enzymatic degradation of xyloglucans by Aspergillus species: a comparative view of this genus. Appl Microbiol Biotechnol 2021; 105:2701-2711. [PMID: 33760931 DOI: 10.1007/s00253-021-11236-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/25/2021] [Accepted: 03/14/2021] [Indexed: 10/21/2022]
Abstract
Aspergillus species are closely associated with humanity through fermentation, infectious disease, and mycotoxin contamination of food. Members of this genus produce various enzymes to degrade plant polysaccharides, including starch, cellulose, xylan, and xyloglucan. This review focus on the machinery of the xyloglucan degradation using glycoside hydrolases, such as xyloglucanases, isoprimeverose-producing oligoxyloglucan hydrolases, and α-xylosidases, in Aspergillus species. Some xyloglucan degradation-related glycoside hydrolases are well conserved in this genus; however, other enzymes are not. Cooperative actions of these glycoside hydrolases are crucial for xyloglucan degradation in Aspergillus species. KEY POINTS: •Xyloglucan degradation-related enzymes of Aspergillus species are reviewed. •Each Aspergillus species possesses a different set of glycoside hydrolases. •The machinery of xyloglucan degradation of A. oryzae is overviewed.
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6
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Possible beneficial effects of xyloglucan from its degradation by gut microbiota. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2020.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Arnal G, Stogios PJ, Asohan J, Attia MA, Skarina T, Viborg AH, Henrissat B, Savchenko A, Brumer H. Substrate specificity, regiospecificity, and processivity in glycoside hydrolase family 74. J Biol Chem 2019; 294:13233-13247. [PMID: 31324716 DOI: 10.1074/jbc.ra119.009861] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/16/2019] [Indexed: 12/11/2022] Open
Abstract
Glycoside hydrolase family 74 (GH74) is a historically important family of endo-β-glucanases. On the basis of early reports of detectable activity on cellulose and soluble cellulose derivatives, GH74 was originally considered to be a "cellulase" family, although more recent studies have generally indicated a high specificity toward the ubiquitous plant cell wall matrix glycan xyloglucan. Previous studies have indicated that GH74 xyloglucanases differ in backbone cleavage regiospecificities and can adopt three distinct hydrolytic modes of action: exo, endo-dissociative, and endo-processive. To improve functional predictions within GH74, here we coupled in-depth biochemical characterization of 17 recombinant proteins with structural biology-based investigations in the context of a comprehensive molecular phylogeny, including all previously characterized family members. Elucidation of four new GH74 tertiary structures, as well as one distantly related dual seven-bladed β-propeller protein from a marine bacterium, highlighted key structure-function relationships along protein evolutionary trajectories. We could define five phylogenetic groups, which delineated the mode of action and the regiospecificity of GH74 members. At the extremes, a major group of enzymes diverged to hydrolyze the backbone of xyloglucan nonspecifically with a dissociative mode of action and relaxed backbone regiospecificity. In contrast, a sister group of GH74 enzymes has evolved a large hydrophobic platform comprising 10 subsites, which facilitates processivity. Overall, the findings of our study refine our understanding of catalysis in GH74, providing a framework for future experimentation as well as for bioinformatics predictions of sequences emerging from (meta)genomic studies.
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Affiliation(s)
- Gregory Arnal
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Jathavan Asohan
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Mohamed A Attia
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Alexander Holm Viborg
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix-Marseille University, 13007 Marseille, France; INRA, USC1408 Architecture et Fonction des Macromolécules Biologiques (AFMB), 13007 Marseille, France
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada; Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
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8
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Nakamichi Y, Fouquet T, Ito S, Watanabe M, Matsushika A, Inoue H. Structural and functional characterization of a bifunctional GH30-7 xylanase B from the filamentous fungus Talaromyces cellulolyticus. J Biol Chem 2019; 294:4065-4078. [PMID: 30655295 DOI: 10.1074/jbc.ra118.007207] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/15/2019] [Indexed: 01/11/2023] Open
Abstract
Glucuronoxylanases are endo-xylanases and members of the glycoside hydrolase family 30 subfamilies 7 (GH30-7) and 8 (GH30-8). Unlike for the well-studied GH30-8 enzymes, the structural and functional characteristics of GH30-7 enzymes remain poorly understood. Here, we report the catalytic properties and three-dimensional structure of GH30-7 xylanase B (Xyn30B) identified from the cellulolytic fungus Talaromyces cellulolyticus Xyn30B efficiently degraded glucuronoxylan to acidic xylooligosaccharides (XOSs), including an α-1,2-linked 4-O-methyl-d-glucuronosyl substituent (MeGlcA). Rapid analysis with negative-mode electrospray-ionization multistage MS (ESI(-)-MS n ) revealed that the structures of the acidic XOS products are the same as those of the hydrolysates (MeGlcA2Xyl n , n > 2) obtained with typical glucuronoxylanases. Acidic XOS products were further degraded by Xyn30B, releasing first xylobiose and then xylotetraose and xylohexaose as transglycosylation products. This hydrolase reaction was unique to Xyn30B, and the substrate was cleaved at the xylobiose unit from its nonreducing end, indicating that Xyn30B is a bifunctional enzyme possessing both endo-glucuronoxylanase and exo-xylobiohydrolase activities. The crystal structure of Xyn30B was determined as the first structure of a GH30-7 xylanase at 2.25 Å resolution, revealing that Xyn30B is composed of a pseudo-(α/β)8-catalytic domain, lacking an α6 helix, and a small β-rich domain. This structure and site-directed mutagenesis clarified that Arg46, conserved in GH30-7 glucuronoxylanases, is a critical residue for MeGlcA appendage-dependent xylan degradation. The structural comparison between Xyn30B and the GH30-8 enzymes suggests that Asn93 in the β2-α2 loop is involved in xylobiohydrolase activity. In summary, our findings indicate that Xyn30B is a bifunctional endo- and exo-xylanase.
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Affiliation(s)
| | - Thierry Fouquet
- the Polymer Chemistry Group, Research Institute for Sustainable Chemistry, AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan, and
| | - Shotaro Ito
- the Bio-based Materials Chemistry Group, Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | | | - Akinori Matsushika
- From the Bioconversion Group and.,the Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
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Structural enzymology reveals the molecular basis of substrate regiospecificity and processivity of an exemplar bacterial glycoside hydrolase family 74 endo-xyloglucanase. Biochem J 2018; 475:3963-3978. [PMID: 30463871 DOI: 10.1042/bcj20180763] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 12/21/2022]
Abstract
Paenibacillus odorifer produces a single multimodular enzyme containing a glycoside hydrolase (GH) family 74 module (AIQ73809). Recombinant production and characterization of the GH74 module (PoGH74cat) revealed a highly specific, processive endo-xyloglucanase that can hydrolyze the polysaccharide backbone at both branched and unbranched positions. X-ray crystal structures obtained for the free enzyme and oligosaccharide complexes evidenced an extensive hydrophobic binding platform - the first in GH74 extending from subsites -4 to +6 - and unique mobile active-site loops. Site-directed mutagenesis revealed that glycine-476 was uniquely responsible for the promiscuous backbone-cleaving activity of PoGH74cat; replacement with tyrosine, which is conserved in many GH74 members, resulted in exclusive hydrolysis at unbranched glucose units. Likewise, systematic replacement of the hydrophobic platform residues constituting the positive subsites indicated their relative contributions to the processive mode of action. Specifically, W347 (+3 subsite) and W348 (+5 subsite) are essential for processivity, while W406 (+2 subsite) and Y372 (+6 subsite) are not strictly essential, but aid processivity.
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10
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Shimizu H, Nakajima M, Miyanaga A, Takahashi Y, Tanaka N, Kobayashi K, Sugimoto N, Nakai H, Taguchi H. Characterization and Structural Analysis of a Novel exo-Type Enzyme Acting on β-1,2-Glucooligosaccharides from Parabacteroides distasonis. Biochemistry 2018; 57:3849-3860. [PMID: 29763309 DOI: 10.1021/acs.biochem.8b00385] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
β-1,2-Glucan is a polysaccharide produced mainly by some Gram-negative bacteria as a symbiosis and infectious factor. We recently identified endo-β-1,2-glucanase from Chitinophaga pinensis ( CpSGL) as an enzyme comprising a new family. Here, we report the characteristics and crystal structure of a CpSGL homologue from Parabacteroides distasonis, an intestinal bacterium (BDI_3064 protein), which exhibits distinctive properties of known β-1,2-glucan-degrading enzymes. BDI_3064 hydrolyzed linear β-1,2-glucan and β-1,2-glucooligosaccharides with degrees of polymerization (DPs) of ≥4 to produce sophorose specifically but did not hydrolyze cyclic β-1,2-glucan. This result indicates that BDI_3064 is a new exo-type enzyme. BDI_3064 also produced sophorose from β-1,2-glucooligosaccharide analogues that have a modified reducing end, indicating that BDI_3064 acts on its substrates from the nonreducing end. The crystal structure showed that BDI_3064 possesses additional N-terminal domains 1 and 2, unlike CpSGL. Superimposition of BDI_3064 and CpSGL complexed with ligands showed that R93 in domain 1 overlapped subsite -3 in CpSGL. Docking analysis involving a β-1,2-glucooligosaccharide with DP4 showed that R93 completely blocks the nonreducing end of the docked β-1,2-glucooligosaccharide. This indicates that BDI_3064 employs a distinct mechanism of recognition at the nonreducing end of substrates to act as an exo-type enzyme. Thus, we propose 2-β-d-glucooligosaccharide sophorohydrolase (nonreducing end) as a systematic name for BDI_3064.
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Affiliation(s)
- Hisaka Shimizu
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Akimasa Miyanaga
- Department of Chemistry , Tokyo Institute of Technology , 2-12-1, O-okayama , Meguro-ku, Tokyo 152-8551 , Japan
| | - Yuta Takahashi
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Nobukiyo Tanaka
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Kaito Kobayashi
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Naohisa Sugimoto
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Hiroyuki Nakai
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
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11
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Affiliation(s)
- R. Rashmi
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, India
| | - K. R. Siddalingamurthy
- Department of Biochemistry, Jnanabharathi Campus, Bangalore University, Bengaluru, India
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12
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Ngugi DK, Miyake S, Cahill M, Vinu M, Hackmann TJ, Blom J, Tietbohl MD, Berumen ML, Stingl U. Genomic diversification of giant enteric symbionts reflects host dietary lifestyles. Proc Natl Acad Sci U S A 2017; 114:E7592-E7601. [PMID: 28835538 PMCID: PMC5594648 DOI: 10.1073/pnas.1703070114] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Herbivorous surgeonfishes are an ecologically successful group of reef fish that rely on marine algae as their principal food source. Here, we elucidated the significance of giant enteric symbionts colonizing these fishes regarding their roles in the digestive processes of hosts feeding predominantly on polysiphonous red algae and brown Turbinaria algae, which contain different polysaccharide constituents. Using metagenomics, single-cell genomics, and metatranscriptomic analyses, we provide evidence of metabolic diversification of enteric microbiota involved in the degradation of algal biomass in these fishes. The enteric microbiota is also phylogenetically and functionally simple relative to the complex lignocellulose-degrading microbiota of terrestrial herbivores. Over 90% of the enzymes for deconstructing algal polysaccharides emanate from members of a single bacterial lineage, "Candidatus Epulopiscium" and related giant bacteria. These symbionts lack cellulases but encode a distinctive and lineage-specific array of mostly intracellular carbohydrases concurrent with the unique and tractable dietary resources of their hosts. Importantly, enzymes initiating the breakdown of the abundant and complex algal polysaccharides also originate from these symbionts. These are also highly transcribed and peak according to the diel lifestyle of their host, further supporting their importance and host-symbiont cospeciation. Because of their distinctive genomic blueprint, we propose the classification of these giant bacteria into three candidate genera. Collectively, our findings show that the acquisition of metabolically distinct "Epulopiscium" symbionts in hosts feeding on compositionally varied algal diets is a key niche-partitioning driver in the nutritional ecology of herbivorous surgeonfishes.
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Affiliation(s)
- David Kamanda Ngugi
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;
| | - Sou Miyake
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Matt Cahill
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Manikandan Vinu
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Timothy J Hackmann
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus Liebig University of Giessen, D-35392 Giessen, Germany
| | - Matthew D Tietbohl
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Michael L Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Ulrich Stingl
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;
- Institute of Food and Agricultural Sciences, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611
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13
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Duan CJ, Huang MY, Pang H, Zhao J, Wu CX, Feng JX. Characterization of a novel theme C glycoside hydrolase family 9 cellulase and its CBM-chimeric enzymes. Appl Microbiol Biotechnol 2017; 101:5723-5737. [DOI: 10.1007/s00253-017-8320-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/09/2017] [Accepted: 04/29/2017] [Indexed: 01/27/2023]
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14
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Damasio ARDL, Rubio MV, Gonçalves TA, Persinoti GF, Segato F, Prade RA, Contesini FJ, de Souza AP, Buckeridge MS, Squina FM. Xyloglucan breakdown by endo-xyloglucanase family 74 from Aspergillus fumigatus. Appl Microbiol Biotechnol 2016; 101:2893-2903. [PMID: 28013403 DOI: 10.1007/s00253-016-8014-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 11/09/2016] [Accepted: 11/12/2016] [Indexed: 12/30/2022]
Abstract
Xyloglucan is the most abundant hemicellulose in primary walls of spermatophytes except for grasses. Xyloglucan-degrading enzymes are important in lignocellulosic biomass hydrolysis because they remove xyloglucan, which is abundant in monocot-derived biomass. Fungal genomes encode numerous xyloglucanase genes, belonging to at least six glycoside hydrolase (GH) families. GH74 endo-xyloglucanases cleave xyloglucan backbones with unsubstituted glucose at the -1 subsite or prefer xylosyl-substituted residues in the -1 subsite. In this work, 137 GH74-related genes were detected by examining 293 Eurotiomycete genomes and Ascomycete fungi contained one or no GH74 xyloglucanase gene per genome. Another interesting feature is that the triad of tryptophan residues along the catalytic cleft was found to be widely conserved among Ascomycetes. The GH74 from Aspergillus fumigatus (AfXEG74) was chosen as an example to conduct comprehensive biochemical studies to determine the catalytic mechanism. AfXEG74 has no CBM and cleaves the xyloglucan backbone between the unsubstituted glucose and xylose-substituted glucose at specific positions, along the XX motif when linked to regions deprived of galactosyl branches. It resembles an endo-processive activity, which after initial random hydrolysis releases xyloglucan-oligosaccharides as major reaction products. This work provides insights on phylogenetic diversity and catalytic mechanism of GH74 xyloglucanases from Ascomycete fungi.
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Affiliation(s)
- André Ricardo de Lima Damasio
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil.,Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Marcelo Ventura Rubio
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil.,Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Thiago Augusto Gonçalves
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil.,Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Gabriela Felix Persinoti
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil
| | - Fernando Segato
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil.,Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), Lorena, SP, Brazil
| | - Rolf Alexander Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Fabiano Jares Contesini
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil
| | - Amanda Pereira de Souza
- Laboratório de Fisiologia e Ecologia de Plantas (LAFIECO), Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Marcos Silveira Buckeridge
- Laboratório de Fisiologia e Ecologia de Plantas (LAFIECO), Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Fabio Marcio Squina
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP, Brazil.
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15
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Recent structural insights into the enzymology of the ubiquitous plant cell wall glycan xyloglucan. Curr Opin Struct Biol 2016; 40:43-53. [PMID: 27475238 DOI: 10.1016/j.sbi.2016.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 01/03/2023]
Abstract
The xyloglucans (XyGs) constitute a family of highly decorated β(1→4)-glucans whose members are widespread and abundant across the plant kingdom. As such, XyGs constitute a significant reserve of metabolically accessible monosaccharides for diverse phytopathogenic, saprophytic, and gut symbiotic micro-organisms. To overcome the intrinsic stability of the diverse glycosidic bonds in XyGs, bacteria and fungi have evolved extensive repertoires of xyloglucan-active enzymes from manifold families, whose exquisitely adapted tertiary structures are recently coming to light.
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16
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Vitcosque GL, Ribeiro LFC, de Lucas RC, da Silva TM, Ribeiro LF, de Lima Damasio AR, Farinas CS, Gonçalves AZL, Segato F, Buckeridge MS, Jorge JA, Polizeli MDLTM. The functional properties of a xyloglucanase (GH12) of Aspergillus terreus expressed in Aspergillus nidulans may increase performance of biomass degradation. Appl Microbiol Biotechnol 2016; 100:9133-9144. [PMID: 27245677 DOI: 10.1007/s00253-016-7589-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/24/2016] [Accepted: 05/04/2016] [Indexed: 11/28/2022]
Abstract
Filamentous fungi are attractive hosts for heterologous protein expression due to their capacity to secrete large amounts of enzymes into the extracellular medium. Xyloglucanases, which specifically hydrolyze xyloglucan, have been recently applied in lignocellulosic biomass degradation and conversion in many other industrial processes. In this context, this work aimed to clone, express, and determine the functional properties of a recombinant xyloglucanase (AtXEG12) from Aspergillus terreus, and also its solid-state (SSF) and submerged (SmF) fermentation in bioreactors. The purified AtXEG12 showed optimum pH and temperature of 5.5 and 65 °C, respectively, demonstrating to be 90 % stable after 24 h of incubation at 50 °C. AtXEG12 activity increased in the presence of 2-mercaptoethanol (65 %) and Zn+2 (45 %), while Cu+2 and Ag+ ions drastically decreased its activity. A substrate assay showed, for the first time for this enzyme's family, xylanase activity. The enzyme exhibited high specificity for tamarind xyloglucan (K M 1.2 mg mL-1) and V max of 17.4 μmol min-1 mg-1 of protein. The capillary zone electrophoresis analysis revealed that AtXEG12 is an endo-xyloglucanase. The heterologous xyloglucanase secretion was greater than the production by wild-type A. terreus cultivated in SmF. On the other hand, AtXEG12 activity reached by SSF was sevenfold higher than values achieved by SmF, showing that the expression of recombinant enzymes can be significantly improved by cultivation under SSF.
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Affiliation(s)
- Gabriela Leal Vitcosque
- Departamento de Bioquímica e Imunologia, FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Liliane Fraga Costa Ribeiro
- Departamento de Bioquímica e Imunologia, FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.,Chemical Biochemical Environmental Engineering Department, University of Maryland, Baltimore County, MD, USA
| | - Rosymar Coutinho de Lucas
- Departamento de Bioquímica e Imunologia, FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.,Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14040-901, Brazil
| | - Tony Marcio da Silva
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14040-901, Brazil.,Instituto de Ciências da Saúde, Agrárias e Humanas do Centro Universitário do Planalto de Araxà (UNIARAXÀ), Araxà, MG, Brazil
| | - Lucas Ferreira Ribeiro
- Departamento de Bioquímica e Imunologia, FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.,Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - André Ricardo de Lima Damasio
- Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade de Campinas, Campinas, SP, Brazil
| | | | - Aline Zorzetto Lopes Gonçalves
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14040-901, Brazil
| | - Fernando Segato
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - João Atilio Jorge
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14040-901, Brazil
| | - Maria de Lourdes T M Polizeli
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14040-901, Brazil.
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17
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Mechanisms involved in xyloglucan catabolism by the cellulosome-producing bacterium Ruminiclostridium cellulolyticum. Sci Rep 2016; 6:22770. [PMID: 26946939 PMCID: PMC4780118 DOI: 10.1038/srep22770] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/23/2016] [Indexed: 12/23/2022] Open
Abstract
Xyloglucan, a ubiquitous highly branched plant polysaccharide, was found to be rapidly degraded and metabolized by the cellulosome-producing bacterium Ruminiclostridium cellulolyticum. Our study shows that at least four cellulosomal enzymes displaying either endo- or exoxyloglucanase activities, achieve the extracellular degradation of xyloglucan into 4-glucosyl backbone xyloglucan oligosaccharides. The released oligosaccharides (composed of up to 9 monosaccharides) are subsequently imported by a highly specific ATP-binding cassette transporter (ABC-transporter), the expression of the corresponding genes being strongly induced by xyloglucan. This polysaccharide also triggers the synthesis of cytoplasmic β-galactosidase, α-xylosidase, and β-glucosidase that act sequentially to convert the imported oligosaccharides into galactose, xylose, glucose and unexpectedly cellobiose. Thus R. cellulolyticum has developed an energy-saving strategy to metabolize this hemicellulosic polysaccharide that relies on the action of the extracellular cellulosomes, a highly specialized ABC-transporter, and cytoplasmic enzymes acting in a specific order. This strategy appears to be widespread among cellulosome-producing mesophilic bacteria which display highly similar gene clusters encoding the cytosolic enzymes and the ABC-transporter.
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18
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Affiliation(s)
- Tomohiko Matsuzawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
| | - Katsuro Yaoi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
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19
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Affiliation(s)
- Tomohiko Matsuzawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
| | - Katsuro Yaoi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
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20
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Abstract
SUMMARY Biomass is constructed of dense recalcitrant polymeric materials: proteins, lignin, and holocellulose, a fraction constituting fibrous cellulose wrapped in hemicellulose-pectin. Bacteria and fungi are abundant in soil and forest floors, actively recycling biomass mainly by extracting sugars from holocellulose degradation. Here we review the genome-wide contents of seven Aspergillus species and unravel hundreds of gene models encoding holocellulose-degrading enzymes. Numerous apparent gene duplications followed functional evolution, grouping similar genes into smaller coherent functional families according to specialized structural features, domain organization, biochemical activity, and genus genome distribution. Aspergilli contain about 37 cellulase gene models, clustered in two mechanistic categories: 27 hydrolyze and 10 oxidize glycosidic bonds. Within the oxidative enzymes, we found two cellobiose dehydrogenases that produce oxygen radicals utilized by eight lytic polysaccharide monooxygenases that oxidize glycosidic linkages, breaking crystalline cellulose chains and making them accessible to hydrolytic enzymes. Among the hydrolases, six cellobiohydrolases with a tunnel-like structural fold embrace single crystalline cellulose chains and cooperate at nonreducing or reducing end termini, splitting off cellobiose. Five endoglucanases group into four structural families and interact randomly and internally with cellulose through an open cleft catalytic domain, and finally, seven extracellular β-glucosidases cleave cellobiose and related oligomers into glucose. Aspergilli contain, on average, 30 hemicellulase and 7 accessory gene models, distributed among 9 distinct functional categories: the backbone-attacking enzymes xylanase, mannosidase, arabinase, and xyloglucanase, the short-side-chain-removing enzymes xylan α-1,2-glucuronidase, arabinofuranosidase, and xylosidase, and the accessory enzymes acetyl xylan and feruloyl esterases.
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21
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Dos Santos CR, Cordeiro RL, Wong DWS, Murakami MT. Structural basis for xyloglucan specificity and α-d-Xylp(1 → 6)-D-Glcp recognition at the -1 subsite within the GH5 family. Biochemistry 2015; 54:1930-42. [PMID: 25714929 DOI: 10.1021/acs.biochem.5b00011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
GH5 is one of the largest glycoside hydrolase families, comprising at least 20 distinct activities within a common structural scaffold. However, the molecular basis for the functional differentiation among GH5 members is still not fully understood, principally for xyloglucan specificity. In this work, we elucidated the crystal structures of two novel GH5 xyloglucanases (XEGs) retrieved from a rumen microflora metagenomic library, in the native state and in complex with xyloglucan-derived oligosaccharides. These results provided insights into the structural determinants that differentiate GH5 XEGs from parental cellulases and a new mode of action within the GH5 family related to structural adaptations in the -1 subsite. The oligosaccharide found in the XEG5A complex, permitted the mapping, for the first time, of the positive subsites of a GH5 XEG, revealing the importance of the pocket-like topology of the +1 subsite in conferring the ability of some GH5 enzymes to attack xyloglucan. Complementarily, the XEG5B complex covered the negative subsites, completing the subsite mapping of GH5 XEGs at high resolution. Interestingly, XEG5B is, to date, the only GH5 member able to cleave XXXG into XX and XG, and in the light of these results, we propose that a modification in the -1 subsite enables the accommodation of a xylosyl side chain at this position. The stereochemical compatibility of the -1 subsite with a xylosyl moiety was also reported for other structurally nonrelated XEGs belonging to the GH74 family, indicating it to be an essential attribute for this mode of action.
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Affiliation(s)
- Camila Ramos Dos Santos
- †Brazilian Biosciences National Laboratory, National Center of Research in Energy and Materials, Campinas, São Paulo 13083-970, Brazil
| | - Rosa Lorizolla Cordeiro
- †Brazilian Biosciences National Laboratory, National Center of Research in Energy and Materials, Campinas, São Paulo 13083-970, Brazil
| | - Dominic W S Wong
- ‡Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, United States
| | - Mário Tyago Murakami
- †Brazilian Biosciences National Laboratory, National Center of Research in Energy and Materials, Campinas, São Paulo 13083-970, Brazil
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22
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Feng T, Yan KP, Mikkelsen MD, Meyer AS, Schols HA, Westereng B, Mikkelsen JD. Characterisation of a novel endo-xyloglucanase (XcXGHA) from Xanthomonas that accommodates a xylosyl-substituted glucose at subsite -1. Appl Microbiol Biotechnol 2014; 98:9667-79. [PMID: 24898632 DOI: 10.1007/s00253-014-5825-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/08/2014] [Accepted: 05/10/2014] [Indexed: 11/26/2022]
Abstract
A xyloglucan-specific endo-1,4β-glucanase (XcXGHA) from Xanthomonas citri pv. mangiferaeindicae has been cloned, expressed in Escherichia coli, purified and characterised. The XcXGHA enzyme belongs to CAZy family GH74 and has catalytic site residues conserved with other xyloglucanases in this family. At its optimal reaction conditions, pH 7.0 and 40 °C, the enzyme has a k cat/K M value of 2.2 × 10(7) min(-1) M(-1) on a tamarind seed xyloglucan substrate. XcXGHA is relatively stable within a broad pH range (pH 4-9) and up to 50 °C (t 1/2, 50 °C of 74 min). XcXGHA is proven to be xyloglucan-specific, and a glycan microarray study verifies that XcXGHA catalyses cleavage of xyloglucan extracted from both monocot and dicot plant species. The enzyme catalyses hydrolysis of tamarind xyloglucan in a unique way by cleaving XXXG into XX and XG (X is xylosyl-substituted glucose; G is unsubstituted glucose), is able to degrade more complex xyloglucans and notably is able to cleave near more substituted xyloglucan motifs such as L [i.e. α-L-Fucp-(1 → 2)-β-D-Galp-(1 → 2)-α-D-Xylp-(1 → 6)-β-D-Glcp]. LC-MS/MS analysis of product profiles of tamarind xyloglucan which had been catalytically degraded by XcXGHA revealed that XcXGHA has specificity for X in subsite -1. The 3D model suggests that XcXGHA consists of two seven-bladed β-propeller domains with the catalytic center formed by the interface of these two domains, which is conserved in xyloglucanases in the GH74 family. However, the XcXGHA has two amino acids (D264 and R472) that differ from the conserved residues of other GH74 xyloglucanases. These two amino acids were predicted to be located on the opposite side of the active site pocket, facing each other and forming a closing surface above the active site pocket. These two amino acids may contribute to the unique substrate specificity of the XcXGHA enzyme.
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Affiliation(s)
- Tao Feng
- Center for BioProcess Engineering, Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads, Building 229, 2800 Kgs, Lyngby, Denmark
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23
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GH52 xylosidase from Geobacillus stearothermophilus: characterization and introduction of xylanase activity by site‑directed mutagenesis of Tyr509. J Ind Microbiol Biotechnol 2014; 41:65-74. [PMID: 24122394 DOI: 10.1007/s10295-013-1351-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
Abstract
A xylosidase gene, gsxyn, was cloned from the deep-sea thermophilic Geobacillus stearothermophilus, which consisted of 2,118 bp and encoded a protein of 705 amino acids with a calculated molecular mass of 79.8 kDa. The GSxyn of glycoside hydrolase family 52 (GH52) displayed its maximum activity at 70 °C and pH 5.5. The K m and k cat values of GSxyn for ρNPX were 0.48 mM and 36.64 s−1, respectively. Interestingly, a new exo-xylanase activity was introduced into GSxyn by mutating the tyrosine509 into glutamic acid, whereas the resultant enzyme variant, Y509E, retained the xylosidase activity. The optimum xylanase activity of theY509E mutant displayed at pH 6.5 and 50 °C, and retained approximately 45 % of its maximal activity at 55 °C, pH 6.5 for 60 min. The K m and k cat values of the xylanase activity of Y509E mutant for beechwood xylan were 5.10 mg/ml and 22.53 s−1, respectively. The optimum xylosidase activity of theY509E mutant displayed at pH 5.5 and 60 °C. The K m and k cat values of the xylosidase activity of Y509E mutant for ρNPX were 0.51 mM and 22.53 s−1, respectively. This report demonstrated that GH52 xylosidase has provided a platform for generating bifunctional enzymes for industrially significant and complex substrates, such as plant cell wall.
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24
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Key amino acid residues for the endo-processive activity of GH74 xyloglucanase. FEBS Lett 2014; 588:1731-8. [PMID: 24657616 DOI: 10.1016/j.febslet.2014.03.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 03/11/2014] [Accepted: 03/11/2014] [Indexed: 11/22/2022]
Abstract
Unlike endo-dissociative-xyloglucanases, Paenibacillus XEG74 is an endo-processive xyloglucanase that contains four unique tryptophan residues in the negative subsites (W61 and W64) and the positive subsites (W318 and W319), as indicated by three-dimensional homology modelling. Selective replacement of the positive subsite residues with alanine mutations reduced the degree of processive activity and resulted in the more endo-dissociative-activity. The results showed that W318 and W319, which are found in the positive subsites, are essential for processive degradation and are responsible for maintaining binding interactions with xyloglucan polysaccharide through a stacking effect.
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25
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Alahuhta M, Adney WS, Himmel ME, Lunin VV. Structure of Acidothermus cellulolyticus family 74 glycoside hydrolase at 1.82 Å resolution. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1335-8. [PMID: 24316824 PMCID: PMC3855714 DOI: 10.1107/s1744309113030005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 11/01/2013] [Indexed: 11/11/2022]
Abstract
Here, a 1.82 Å resolution X-ray structure of a glycoside hydrolase family 74 (GH74) enzyme from Acidothermus cellulolyticus is reported. The resulting structure was refined to an R factor of 0.150 and an Rfree of 0.196. Structural analysis shows that five related structures have been reported with a secondary-structure similarity of between 75 and 89%. The five similar structures were all either Clostridium thermocellum or Geotrichum sp. M128 GH74 xyloglucanases. Structural analysis indicates that the A. cellulolyticus GH74 enzyme is an endoxyloglucanase, as it lacks a characteristic loop that blocks one end of the active site in exoxyloglucanases. Superimposition with the C. thermocellum GH74 shows that Asp451 and Asp38 are the catalytic residues.
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Affiliation(s)
- Markus Alahuhta
- BioSciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - William S. Adney
- BioSciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Michael E. Himmel
- BioSciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Vladimir V. Lunin
- BioSciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
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26
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de Araújo EA, Tomazini A, Kadowaki MAS, Murakami MT, Polikarpov I. Crystallization and preliminary X-ray diffraction analysis of a new xyloglucanase from Xanthomonas campestris pv. campestris. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:676-8. [PMID: 23722852 PMCID: PMC3668593 DOI: 10.1107/s174430911301275x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/09/2013] [Indexed: 06/02/2023]
Abstract
Xyloglucanases (Xghs) are important enzymes involved in xyloglucan modification and degradation. Xanthomonas campestris pv. campestris (Xcc) is a phytopathogenic bacterium which produces a large number of glycosyl hydrolases (GH), but has only one family 74 GH (Xcc-Xgh). This enzyme was overexpressed in Escherichia coli, purified and crystallized. Diffraction data sets were collected for the native enzyme and its complex with glucose to maximum resolutions of 2.0 and 2.1 Å, respectively. The data were indexed in a hexagonal crystal system with unit-cell parameters a = b = 153.4, c = 84.9 Å. As indicated by molecular-replacement solution, the crystals belonged to space group P6(1).
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Affiliation(s)
- Evandro Ares de Araújo
- Instituto de Física de São Carlos, Universidade de São Paulo, 400 Trabalhador Saocarlense, 13566-590 São Carlos-SP, Brazil
| | - Atílio Tomazini
- Instituto de Física de São Carlos, Universidade de São Paulo, 400 Trabalhador Saocarlense, 13566-590 São Carlos-SP, Brazil
| | - Marco Antonio Seiki Kadowaki
- Instituto de Física de São Carlos, Universidade de São Paulo, 400 Trabalhador Saocarlense, 13566-590 São Carlos-SP, Brazil
| | - Mário Tyago Murakami
- Laboratório Nacional de Biociências, CNPEM, 10000 Giuseppe Máximo Scolfaro, 13083-100, Campinas-SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, 400 Trabalhador Saocarlense, 13566-590 São Carlos-SP, Brazil
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Segato F, Damasio ARL, Gonçalves TA, Murakami MT, Squina FM, Polizeli M, Mort AJ, Prade RA. Two structurally discrete GH7-cellobiohydrolases compete for the same cellulosic substrate fiber. BIOTECHNOLOGY FOR BIOFUELS 2012; 5:21. [PMID: 22494694 PMCID: PMC3431977 DOI: 10.1186/1754-6834-5-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 03/30/2012] [Indexed: 05/14/2023]
Abstract
BACKGROUND Cellulose consisting of arrays of linear beta-1,4 linked glucans, is the most abundant carbon-containing polymer present in biomass. Recalcitrance of crystalline cellulose towards enzymatic degradation is widely reported and is the result of intra- and inter-molecular hydrogen bonds within and among the linear glucans. Cellobiohydrolases are enzymes that attack crystalline cellulose. Here we report on two forms of glycosyl hydrolase family 7 cellobiohydrolases common to all Aspergillii that attack Avicel, cotton cellulose and other forms of crystalline cellulose. RESULTS Cellobiohydrolases Cbh1 and CelD have similar catalytic domains but only Cbh1 contains a carbohydrate-binding domain (CBD) that binds to cellulose. Structural superpositioning of Cbh1 and CelD on the Talaromyces emersonii Cel7A 3-dimensional structure, identifies the typical tunnel-like catalytic active site while Cbh1 shows an additional loop that partially obstructs the substrate-fitting channel. CelD does not have a CBD and shows a four amino acid residue deletion on the tunnel-obstructing loop providing a continuous opening in the absence of a CBD. Cbh1 and CelD are catalytically functional and while specific activity against Avicel is 7.7 and 0.5 U.mg prot-1, respectively specific activity on pNPC is virtually identical. Cbh1 is slightly more stable to thermal inactivation compared to CelD and is much less sensitive to glucose inhibition suggesting that an open tunnel configuration, or absence of a CBD, alters the way the catalytic domain interacts with the substrate. Cbh1 and CelD enzyme mixtures on crystalline cellulosic substrates show a strong combinatorial effort response for mixtures where Cbh1 is present in 2:1 or 4:1 molar excess. When CelD was overrepresented the combinatorial effort could only be partially overcome. CelD appears to bind and hydrolyze only loose cellulosic chains while Cbh1 is capable of opening new cellulosic substrate molecules away from the cellulosic fiber. CONCLUSION Cellobiohydrolases both with and without a CBD occur in most fungal genomes where both enzymes are secreted, and likely participate in cellulose degradation. The fact that only Cbh1 binds to the substrate and in combination with CelD exhibits strong synergy only when Cbh1 is present in excess, suggests that Cbh1 unties enough chains from cellulose fibers, thus enabling processive access of CelD.
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Affiliation(s)
- Fernando Segato
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisas em Energia e Materiais, Campinas, Sao Paulo, Brazil
| | - André R L Damasio
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
- Department of Biochemistry, Ribeirão Preto School of Medicine, Ribeirão Preto, Sao Paulo, Brazil
| | - Thiago Augusto Gonçalves
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisas em Energia e Materiais, Campinas, Sao Paulo, Brazil
| | - Mario T Murakami
- Laboratório Nacional de Biociências (LNBio), Campinas, Sao Paulo, Brazil
| | - Fabio M Squina
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisas em Energia e Materiais, Campinas, Sao Paulo, Brazil
| | | | - Andrew J Mort
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, USA
| | - Rolf A Prade
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisas em Energia e Materiais, Campinas, Sao Paulo, Brazil
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Introducing endo-xylanase activity into an exo-acting arabinofuranosidase that targets side chains. Proc Natl Acad Sci U S A 2012; 109:6537-42. [PMID: 22492980 DOI: 10.1073/pnas.1117686109] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The degradation of the plant cell wall by glycoside hydrolases is central to environmentally sustainable industries. The major polysaccharides of the plant cell wall are cellulose and xylan, a highly decorated β-1,4-xylopyranose polymer. Glycoside hydrolases displaying multiple catalytic functions may simplify the enzymes required to degrade plant cell walls, increasing the industrial potential of these composite structures. Here we test the hypothesis that glycoside hydrolase family 43 (GH43) provides a suitable scaffold for introducing additional catalytic functions into enzymes that target complex structures in the plant cell wall. We report the crystal structure of Humicola insolens AXHd3 (HiAXHd3), a GH43 arabinofuranosidase that hydrolyses O3-linked arabinose of doubly substituted xylans, a feature of the polysaccharide that is recalcitrant to degradation. HiAXHd3 displays an N-terminal five-bladed β-propeller domain and a C-terminal β-sandwich domain. The interface between the domains comprises a xylan binding cleft that houses the active site pocket. Substrate specificity is conferred by a shallow arabinose binding pocket adjacent to the deep active site pocket, and through the orientation of the xylan backbone. Modification of the rim of the active site introduces endo-xylanase activity, whereas the resultant enzyme variant, Y166A, retains arabinofuranosidase activity. These data show that the active site of HiAXHd3 is tuned to hydrolyse arabinofuranosyl or xylosyl linkages, and it is the topology of the distal regions of the substrate binding surface that confers specificity. This report demonstrates that GH43 provides a platform for generating bespoke multifunctional enzymes that target industrially significant complex substrates, exemplified by the plant cell wall.
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Abstract
The ability of β-glucanases to cleave xyloglucans, a family of highly decorated β-glucans ubiquitous in plant biomass, has traditionally been overlooked in functional biochemical studies. An emerging body of data indicates, however, that a spectrum of xyloglucan specificity resides in diverse glycoside hydrolases from a range of carbohydrate-active enzyme families-including classic "cellulase" families. This chapter outlines a series of enzyme kinetic and product analysis methods to establish degrees of xyloglucan specificity and modes of action of glycosidases emerging from enzyme discovery projects.
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Affiliation(s)
- Jens M Eklöf
- Michael Smith Laboratories and Department of Chemistry, University of British Columbia, Vancouver, Canada
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30
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Ariza A, Eklöf JM, Spadiut O, Offen WA, Roberts SM, Besenmatter W, Friis EP, Skjøt M, Wilson KS, Brumer H, Davies G. Structure and activity of Paenibacillus polymyxa xyloglucanase from glycoside hydrolase family 44. J Biol Chem 2011; 286:33890-900. [PMID: 21795708 PMCID: PMC3190823 DOI: 10.1074/jbc.m111.262345] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 07/12/2011] [Indexed: 11/06/2022] Open
Abstract
The enzymatic degradation of plant polysaccharides is emerging as one of the key environmental goals of the early 21st century, impacting on many processes in the textile and detergent industries as well as biomass conversion to biofuels. One of the well known problems with the use of nonstarch (nonfood)-based substrates such as the plant cell wall is that the cellulose fibers are embedded in a network of diverse polysaccharides, including xyloglucan, that renders access difficult. There is therefore increasing interest in the "accessory enzymes," including xyloglucanases, that may aid biomass degradation through removal of "hemicellulose" polysaccharides. Here, we report the biochemical characterization of the endo-β-1,4-(xylo)glucan hydrolase from Paenibacillus polymyxa with polymeric, oligomeric, and defined chromogenic aryl-oligosaccharide substrates. The enzyme displays an unusual specificity on defined xyloglucan oligosaccharides, cleaving the XXXG-XXXG repeat into XXX and GXXXG. Kinetic analysis on defined oligosaccharides and on aryl-glycosides suggests that both the -4 and +1 subsites show discrimination against xylose-appended glucosides. The three-dimensional structures of PpXG44 have been solved both in apo-form and as a series of ligand complexes that map the -3 to -1 and +1 to +5 subsites of the extended ligand binding cleft. Complex structures are consistent with partial intolerance of xylosides in the -4' subsites. The atypical specificity of PpXG44 may thus find use in industrial processes involving xyloglucan degradation, such as biomass conversion, or in the emerging exciting applications of defined xyloglucans in food, pharmaceuticals, and cellulose fiber modification.
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Affiliation(s)
- Antonio Ariza
- From the Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Jens M. Eklöf
- the Division of Glycoscience, School of Biotechnology, and
| | - Oliver Spadiut
- the Division of Glycoscience, School of Biotechnology, and
- Wallenberg Wood Science Center, Royal Institute of Technology, SE-106 91 Stockholm, Sweden, and
| | - Wendy A. Offen
- From the Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Shirley M. Roberts
- From the Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | | | | | | | - Keith S. Wilson
- From the Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Harry Brumer
- the Division of Glycoscience, School of Biotechnology, and
- Wallenberg Wood Science Center, Royal Institute of Technology, SE-106 91 Stockholm, Sweden, and
| | - Gideon Davies
- From the Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
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Abstract
Cellulose is an abundant and renewable biopolymer that can be used for biofuel generation; however, structural entrapment with other cell wall components hinders enzyme-substrate interactions, a key bottleneck for ethanol production. Biomass is routinely subjected to treatments that facilitate cellulase-cellulose contacts. Cellulases and glucosidases act by hydrolyzing glycosidic bonds of linear glucose β-1,4-linked polymers, producing glucose. Here we describe eight high-temperature-operating cellulases (TCel enzymes) identified from a survey of thermobacterial and archaeal genomes. Three TCel enzymes preferentially hydrolyzed soluble cellulose, while two preferred insoluble cellulose such as cotton linters and filter paper. TCel enzymes had temperature optima ranging from 85°C to 102°C. TCel enzymes were stable, retaining 80% of initial activity after 120 h at 85°C. Two modes of cellulose breakdown, i.e., with endo- and exo-acting glucanases, were detected, and with two-enzyme combinations at 85°C, synergistic cellulase activity was observed for some enzyme combinations.
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32
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Qi M, Wang P, O'Toole N, Barboza PS, Ungerfeld E, Leigh MB, Selinger LB, Butler G, Tsang A, McAllister TA, Forster RJ. Snapshot of the eukaryotic gene expression in muskoxen rumen--a metatranscriptomic approach. PLoS One 2011; 6:e20521. [PMID: 21655220 PMCID: PMC3105075 DOI: 10.1371/journal.pone.0020521] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 05/01/2011] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Herbivores rely on digestive tract lignocellulolytic microorganisms, including bacteria, fungi and protozoa, to derive energy and carbon from plant cell wall polysaccharides. Culture independent metagenomic studies have been used to reveal the genetic content of the bacterial species within gut microbiomes. However, the nature of the genes encoded by eukaryotic protozoa and fungi within these environments has not been explored using metagenomic or metatranscriptomic approaches. METHODOLOGY/PRINCIPAL FINDINGS In this study, a metatranscriptomic approach was used to investigate the functional diversity of the eukaryotic microorganisms within the rumen of muskoxen (Ovibos moschatus), with a focus on plant cell wall degrading enzymes. Polyadenylated RNA (mRNA) was sequenced on the Illumina Genome Analyzer II system and 2.8 gigabases of sequences were obtained and 59129 contigs assembled. Plant cell wall degrading enzyme modules including glycoside hydrolases, carbohydrate esterases and polysaccharide lyases were identified from over 2500 contigs. These included a number of glycoside hydrolase family 6 (GH6), GH48 and swollenin modules, which have rarely been described in previous gut metagenomic studies. CONCLUSIONS/SIGNIFICANCE The muskoxen rumen metatranscriptome demonstrates a much higher percentage of cellulase enzyme discovery and an 8.7x higher rate of total carbohydrate active enzyme discovery per gigabase of sequence than previous rumen metagenomes. This study provides a snapshot of eukaryotic gene expression in the muskoxen rumen, and identifies a number of candidate genes coding for potentially valuable lignocellulolytic enzymes.
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Affiliation(s)
- Meng Qi
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Pan Wang
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Nicholas O'Toole
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Perry S. Barboza
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Emilio Ungerfeld
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Mary Beth Leigh
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - L. Brent Selinger
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Greg Butler
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Tim A. McAllister
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Robert J. Forster
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
- * E-mail:
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Correia MAS, Mazumder K, Brás JLA, Firbank SJ, Zhu Y, Lewis RJ, York WS, Fontes CMGA, Gilbert HJ. Structure and function of an arabinoxylan-specific xylanase. J Biol Chem 2011; 286:22510-20. [PMID: 21378160 DOI: 10.1074/jbc.m110.217315] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzymatic degradation of plant cell walls plays a central role in the carbon cycle and is of increasing environmental and industrial significance. The enzymes that catalyze this process include xylanases that degrade xylan, a β-1,4-xylose polymer that is decorated with various sugars. Although xylanases efficiently hydrolyze unsubstituted xylans, these enzymes are unable to access highly decorated forms of the polysaccharide, such as arabinoxylans that contain arabinofuranose decorations. Here, we show that a Clostridium thermocellum enzyme, designated CtXyl5A, hydrolyzes arabinoxylans but does not attack unsubstituted xylans. Analysis of the reaction products generated by CtXyl5A showed that all the oligosaccharides contain an O3 arabinose linked to the reducing end xylose. The crystal structure of the catalytic module (CtGH5) of CtXyl5A, appended to a family 6 noncatalytic carbohydrate-binding module (CtCBM6), showed that CtGH5 displays a canonical (α/β)(8)-barrel fold with the substrate binding cleft running along the surface of the protein. The catalytic apparatus is housed in the center of the cleft. Adjacent to the -1 subsite is a pocket that could accommodate an l-arabinofuranose-linked α-1,3 to the active site xylose, which is likely to function as a key specificity determinant. CtCBM6, which adopts a β-sandwich fold, recognizes the termini of xylo- and gluco-configured oligosaccharides, consistent with the pocket topology displayed by the ligand-binding site. In contrast to typical modular glycoside hydrolases, there is an extensive hydrophobic interface between CtGH5 and CtCBM6, and thus the two modules cannot function as independent entities.
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Affiliation(s)
- Márcia A S Correia
- Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
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Miyazaki K. MEGAWHOP cloning: a method of creating random mutagenesis libraries via megaprimer PCR of whole plasmids. Methods Enzymol 2011; 498:399-406. [PMID: 21601687 DOI: 10.1016/b978-0-12-385120-8.00017-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
MEGAWHOP allows for the cloning of DNA fragments into a vector and is used for conventional restriction digestion/ligation-based procedures. In MEGAWHOP, the DNA fragment to be cloned is used as a set of complementary primers that replace a homologous region in a template vector through whole-plasmid PCR. After synthesis of a nicked circular plasmid, the mixture is treated with DpnI, a dam-methylated DNA-specific restriction enzyme, to digest the template plasmid. The DpnI-treated mixture is then introduced into competent Escherichia coli cells to yield plasmids carrying replaced insert fragments. Plasmids produced by the MEGAWHOP method are virtually free of contamination by species without any inserts or with multiple inserts, and also the parent. Because the fragment is usually long enough to not interfere with hybridization to the template, various types of fragments can be used with mutations at any site (either known or unknown, random, or specific). By using fragments having homologous sequences at the ends (e.g., adaptor sequence), MEGAWHOP can also be used to recombine nonhomologous sequences mediated by the adaptors, allowing rapid creation of novel constructs and chimeric genes.
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Affiliation(s)
- Kentaro Miyazaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan
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35
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Wong DDWS, Chan VJ, McCormack AA, Batt SB. A novel xyloglucan-specific endo-β-1,4-glucanase: biochemical properties and inhibition studies. Appl Microbiol Biotechnol 2009; 86:1463-71. [DOI: 10.1007/s00253-009-2364-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 11/30/2022]
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36
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Yaoi K, Kondo H, Hiyoshi A, Noro N, Sugimoto H, Tsuda S, Miyazaki K. The crystal structure of a xyloglucan-specific endo-beta-1,4-glucanase from Geotrichum sp. M128 xyloglucanase reveals a key amino acid residue for substrate specificity. FEBS J 2009; 276:5094-100. [PMID: 19682300 DOI: 10.1111/j.1742-4658.2009.07205.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Geotrichum sp. M128 possesses two xyloglucan-specific glycoside hydrolases belonging to family 74, xyloglucan-specific endo-beta-1,4-glucanase (XEG) and oligoxyloglucan reducing-end-specific cellobiohydrolase (OXG-RCBH). Despite their similar amino acid sequences (48% identity), their modes of action and substrate specificities are distinct. XEG catalyzes the hydrolysis of xyloglucan polysaccharides in endo mode, while OXG-RCBH acts on xyloglucan oligosaccharides at the reducing end in exo mode. Here, we determined the crystal structure of XEG at 2.5 A resolution, and compared it to a previously determined structure of OXG-RCBH. For the most part, the amino acid residues that interact with substrate are conserved between the two enzymes. However, there are notable differences at subsite positions -1 and +2. OXG-RCBH has a loop around the +2 site that blocks one end of the active site cleft, which accounts for its exo mode of action. In contrast, XEG lacks a corresponding loop at this site, thereby allowing binding to the middle of the main chain of the substrate. At the -1 site in OXG-RCBH, Asn488 interacts with the xylose side chain of the substrate, whereas the -1 site is occupied by Tyr457 in XEG. To confirm the contribution of this residue to substrate specificity, Tyr457 was substituted by Gly in XEG. The wild-type XEG cleaved the oligoxyloglucan at a specific site; the Y457G variant cleaved the same substrate, but at various sites. Together, the absence of a loop in the cleft and the presence of bulky Tyr457 determine the substrate specificity of XEG.
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Affiliation(s)
- Katsuro Yaoi
- Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
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Ochiai A, Itoh T, Mikami B, Hashimoto W, Murata K. Structural determinants responsible for substrate recognition and mode of action in family 11 polysaccharide lyases. J Biol Chem 2009; 284:10181-9. [PMID: 19193638 PMCID: PMC2665072 DOI: 10.1074/jbc.m807799200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 12/29/2008] [Indexed: 11/06/2022] Open
Abstract
A saprophytic Bacillus subtilis secretes two types of rhamnogalacturonan (RG) lyases, endotype YesW and exotype YesX, which are responsible for an initial cleavage of the RG type I (RG-I) region of plant cell wall pectin. Polysaccharide lyase family 11 YesW and YesX with a significant sequence identity (67.8%) cleave glycoside bonds between rhamnose and galacturonic acid residues in RG-I through a beta-elimination reaction. Here we show the structural determinants for substrate recognition and the mode of action in polysaccharide lyase family 11 lyases. The crystal structures of YesW in complex with rhamnose and ligand-free YesX were determined at 1.32 and 1.65 A resolution, respectively. The YesW amino acid residues such as Asn(152), Asp(172), Asn(532), Gly(533), Thr(534), and Tyr(595) in the active cleft bind to rhamnose molecules through hydrogen bonds and van der Waals contacts. Other rhamnose molecules are accommodated at the noncatalytic domain far from the active cleft, revealing that the domain possibly functions as a novel carbohydrate-binding module. A structural comparison between YesW and YesX indicates that a specific loop in YesX for recognizing the terminal saccharide molecule sterically inhibits penetration of the polymer over the active cleft. The loop-deficient YesX mutant exhibits YesW-like endotype activity, demonstrating that molecular conversion regarding the mode of action is achieved by the addition/removal of the loop for recognizing the terminal saccharide. This is the first report on a structural insight into RG-I recognition and molecular conversion of exotype to endotype in polysaccharide lyases.
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Ibatullin FM, Baumann MJ, Greffe L, Brumer H. Kinetic Analyses of Retaining endo-(Xylo)glucanases from Plant and Microbial Sources Using New Chromogenic Xylogluco-Oligosaccharide Aryl Glycosides. Biochemistry 2008; 47:7762-9. [DOI: 10.1021/bi8009168] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Farid M. Ibatullin
- School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91 Stockholm, Sweden, and Petersburg Nuclear Physics Institute, Molecular and Radiation Biology Division, Russian Academy of Science, Gatchina, St. Petersburg 188300, Russia
| | - Martin J. Baumann
- School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91 Stockholm, Sweden, and Petersburg Nuclear Physics Institute, Molecular and Radiation Biology Division, Russian Academy of Science, Gatchina, St. Petersburg 188300, Russia
| | - Lionel Greffe
- School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91 Stockholm, Sweden, and Petersburg Nuclear Physics Institute, Molecular and Radiation Biology Division, Russian Academy of Science, Gatchina, St. Petersburg 188300, Russia
| | - Harry Brumer
- School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91 Stockholm, Sweden, and Petersburg Nuclear Physics Institute, Molecular and Radiation Biology Division, Russian Academy of Science, Gatchina, St. Petersburg 188300, Russia
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Ishida T, Yaoi K, Hiyoshi A, Igarashi K, Samejima M. Substrate recognition by glycoside hydrolase family 74 xyloglucanase from the basidiomycetePhanerochaete chrysosporium. FEBS J 2007; 274:5727-36. [DOI: 10.1111/j.1742-4658.2007.06092.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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