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Biochemical Characterization of an Endoglucanase GH7 from Thermophile Thermothielavioides terrestris Expressed on Aspergillus nidulans. Catalysts 2023. [DOI: 10.3390/catal13030582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Endoglucanases (EC 3.2.1.4) are important enzymes involved in the hydrolysis of cellulose, acting randomly in the β-1,4-glycosidic bonds present in the amorphous regions of the polysaccharide chain. These biocatalysts have been classified into 14 glycosyl hydrolase (GH) families. The GH7 family is of particular interest since it may act on a broad range of substrates, including cellulose, β-glucan, and xylan, an attractive feature for biotechnological applications, especially in the renewable energy field. In the current work, a gene from the thermophilic fungus Thermothielavioides terrestris, encoding an endoglucanase GH7 (TtCel7B), was cloned in the secretion vector pEXPYR and transformed into the high-protein-producing strain Aspergillus nidulans A773. Purified TtCel7B has a molecular weight of approximately 66 kDa, evidenced by SDS-PAGE. Circular dichroism confirmed the high β-strand content consistent with the canonical GH7 family β-jellyroll fold, also observed in the 3D homology model of TtCel7B. Biochemical characterization assays showed that TtCel7B was active over a wide range of pH values (3.5–7.0) and temperatures (45–70 °C), with the highest activity at pH 4.0 and 65 °C. TtCel7B also was stable over a wide range of pH values (3.5–9.0), maintaining more than 80% of its activity after 24 h. The KM and Vmax values in low-viscosity carboxymethylcellulose were 9.3 mg mL−1 and 2.5 × 104 U mg−1, respectively. The results obtained in this work provide a basis for the development of applications of recombinant TtCel7B in the renewable energy field.
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Hengge NN, Mallinson SJB, Pason P, Lunin VV, Alahuhta M, Chung D, Himmel ME, Westpheling J, Bomble YJ. Characterization of the Biomass Degrading Enzyme GuxA from Acidothermus cellulolyticus. Int J Mol Sci 2022; 23:ijms23116070. [PMID: 35682749 PMCID: PMC9181691 DOI: 10.3390/ijms23116070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 11/16/2022] Open
Abstract
Microbial conversion of biomass relies on a complex combination of enzyme systems promoting synergy to overcome biomass recalcitrance. Some thermophilic bacteria have been shown to exhibit particularly high levels of cellulolytic activity, making them of particular interest for biomass conversion. These bacteria use varying combinations of CAZymes that vary in complexity from a single catalytic domain to large multi-modular and multi-functional architectures to deconstruct biomass. Since the discovery of CelA from Caldicellulosiruptor bescii which was identified as one of the most active cellulase so far identified, the search for efficient multi-modular and multi-functional CAZymes has intensified. One of these candidates, GuxA (previously Acel_0615), was recently shown to exhibit synergy with other CAZymes in C. bescii, leading to a dramatic increase in growth on biomass when expressed in this host. GuxA is a multi-modular and multi-functional enzyme from Acidothermus cellulolyticus whose catalytic domains include a xylanase/endoglucanase GH12 and an exoglucanase GH6, representing a unique combination of these two glycoside hydrolase families in a single CAZyme. These attributes make GuxA of particular interest as a potential candidate for thermophilic industrial enzyme preparations. Here, we present a more complete characterization of GuxA to understand the mechanism of its activity and substrate specificity. In addition, we demonstrate that GuxA exhibits high levels of synergism with E1, a companion endoglucanase from A. cellulolyticus. We also present a crystal structure of one of the GuxA domains and dissect the structural features that might contribute to its thermotolerance.
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Affiliation(s)
- Neal N. Hengge
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Sam J. B. Mallinson
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Patthra Pason
- Pilot Plant Development and Training Institute, King Mongkut’s University of Technology Thonburi, Bangkok 10150, Thailand;
| | - Vladimir V. Lunin
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Daehwan Chung
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
| | - Janet Westpheling
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA; (N.N.H.); (S.J.B.M.); (V.V.L.); (M.A.); (D.C.); (M.E.H.)
- Correspondence:
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Rykov SV, Selimzyanova AI, Nikolaeva AY, Lazarenko VA, Tsurin NV, Akentyev PI, Zverlov VV, Liebl W, Schwarz WH, Berezina OV. Unusual substrate specificity in GH family 12: structure-function analysis of glucanases Bgh12A and Xgh12B from Aspergillus cervinus, and Egh12 from Thielavia terrestris. Appl Microbiol Biotechnol 2022; 106:1493-1509. [PMID: 35129654 DOI: 10.1007/s00253-022-11811-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 01/17/2022] [Accepted: 01/26/2022] [Indexed: 11/28/2022]
Abstract
In this study, we compared the properties and structures of three fungal GH12 enzymes: the strict endoglucanase Bgh12A and the xyloglucanase Xgh12B from Aspergillus cervinus, and the endoglucanase Egh12 from Thielavia terrestris combining activity on linear β-glucan and branched xyloglucan. Egh12 from T. terrestris was produced in Pichia pastoris, purified, and characterized as a thermostable enzyme with maximal activity at 70 ºC and a half-life time of 138 min at 65 °C. We for the first time demonstrated that the GH12 endoglucanases Egh12 and Bgh12A, but not the strict xyloglucanase Xgh12B, hydrolyzed (1,3)-β-linkages in (1,3;1,4)-β-D-glucooligosaccharides and had transglycosylase activity on (1,3)-β-D-glucooligosaccharides. Phylogenetic analysis indicated that Egh12 from T. terrestris and Bgh12A from A. cervinus are more related than Bgh12A and Xgh12B isolated from one strain. The X-ray structure of Bgh12A was determined with 2.17 Å resolution and compared with 3D-homology models of Egh12 and Xgh12B. The enzymes have a β-jelly roll structure with a catalytic cleft running across the protein. Comparative analysis and a docking study demonstrated the importance of endoglucanase-specific loop 1 partly covering the catalytic cleft for correct placement of the linear substrates. Variability in substrate specificity between the GH12 endoglucanases is determined by non-conservative residues in structural loops framing the catalytic cleft. A residue responsible for the thermostability of Egh12 was predicted. The key structural elements and residues described in this study may serve as potential targets for modification aimed at the improvement of enzymatic properties. KEY POINTS: • Thermostable endoglucanase Egh12 from T. terrestris was produced in P. pastoris, purified, and characterized • The X-ray structure of GH12 endoglucanase Bgh12A from A. cervinus was resolved • GH12 endoglucanases, but not GH12 xyloglucanases, hydrolyze (1,3)-β-linkages in (1,3;1,4)-β-D-glucooligosaccharides.
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Affiliation(s)
- Sergey V Rykov
- National Research Center «Kurchatov Institute» - GOSNIIGENETIKA, Kurchatov Genomic Center, 1-st Dorozhniy pr. 1, 117545, Moscow, Russian Federation.,National Research Center «Kurchatov Institute», Kurchatov Sq. 1, 123182, Moscow, Russian Federation
| | - Alina I Selimzyanova
- National Research Center «Kurchatov Institute» - GOSNIIGENETIKA, Kurchatov Genomic Center, 1-st Dorozhniy pr. 1, 117545, Moscow, Russian Federation
| | - Alena Y Nikolaeva
- National Research Center «Kurchatov Institute» - Institute of Molecular Genetics, Kurchatov Sq. 2, 123182, Moscow, Russian Federation
| | - Vladimir A Lazarenko
- National Research Center «Kurchatov Institute» - Institute of Molecular Genetics, Kurchatov Sq. 2, 123182, Moscow, Russian Federation
| | - Nikita V Tsurin
- National Research Center «Kurchatov Institute» - GOSNIIGENETIKA, Kurchatov Genomic Center, 1-st Dorozhniy pr. 1, 117545, Moscow, Russian Federation
| | - Philipp I Akentyev
- National Research Center «Kurchatov Institute» - GOSNIIGENETIKA, Kurchatov Genomic Center, 1-st Dorozhniy pr. 1, 117545, Moscow, Russian Federation.,National Research Center «Kurchatov Institute», Kurchatov Sq. 1, 123182, Moscow, Russian Federation
| | - Vladimir V Zverlov
- National Research Center «Kurchatov Institute» - Institute of Molecular Genetics, Kurchatov Sq. 2, 123182, Moscow, Russian Federation. .,Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany.
| | - Wolfgang Liebl
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | | | - Oksana V Berezina
- National Research Center «Kurchatov Institute» - GOSNIIGENETIKA, Kurchatov Genomic Center, 1-st Dorozhniy pr. 1, 117545, Moscow, Russian Federation. .,National Research Center «Kurchatov Institute», Kurchatov Sq. 1, 123182, Moscow, Russian Federation.
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Zhang L, Yan J, Fu Z, Shi W, Ninkuu V, Li G, Yang X, Zeng H. FoEG1, a secreted glycoside hydrolase family 12 protein from Fusarium oxysporum, triggers cell death and modulates plant immunity. MOLECULAR PLANT PATHOLOGY 2021; 22:522-538. [PMID: 33675158 PMCID: PMC8035634 DOI: 10.1111/mpp.13041] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 05/19/2023]
Abstract
Fusarium oxysporum is an important soilborne fungal pathogen with many different formae speciales that can colonize the plant vascular system and cause serious crop wilt disease worldwide. We found a glycoside hydrolase family 12 protein FoEG1, secreted by F. oxysporum, that acted as a pathogen-associated molecular pattern (PAMP) targeting the apoplast of plants to induce cell death. Purified FoEG1 protein triggered cell death in different plants and induced the plant defence response to enhance the disease resistance of plants. The ability of FoEG1 to induce cell death was mediated by leucine-rich repeat (LRR) receptor-like kinases BAK1 and SOBIR1, and this ability was independent of its hydrolase activity. The mutants of cysteine residues did not affect the ability of FoEG1 to induce cell death, and an 86 amino acid fragment from amino acid positions 144 to 229 of FoEG1 was sufficient to induce cell death in Nicotiana benthamiana. In addition, the expression of FoEG1 was strongly induced in the early stage of F. oxysporum infection of host plants, and FoEG1 deletion or loss of enzyme activity reduced the virulence of F. oxysporum. Therefore, our results suggest that FoEG1 can contribute to the virulence of F. oxysporum depending on its enzyme activity and can also act as a PAMP to induce plant defence responses.
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Affiliation(s)
- Lin Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Jianpei Yan
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Zhenchao Fu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Wenjiong Shi
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Vincent Ninkuu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Guangyue Li
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xiufen Yang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Hongmei Zeng
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
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Arevalos-Sánchez MM, Maynez-Perez AO, Rodríguez-Almeida FA, Martínez-Quintana JA, Sanchez-Flores FA, Felix-Portillo M, Chavéz-Martínez A, Olvera-García ME, Ruiz-Barrera O, Corral-Luna A. In vitro assessment of two novel Cellulases from Trabulsiella odontotermitis for agricultural waste utilization. BMC Biotechnol 2021; 21:26. [PMID: 33757473 PMCID: PMC7986525 DOI: 10.1186/s12896-021-00687-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/12/2021] [Indexed: 01/08/2023] Open
Abstract
Background The production of agricultural wastes still growing as a consequence of the population growing. However, the majority of these residues are under-utilized due their chemical composition, which is mainly composed by cellulose. Actually, the search of cellulases with high efficiency to degrade this carbohydrate remains as the challenge. In the present experiment, two genes encoding an endoglucanase (EC 3.2.1.4) and β-glucosidase (EC 3.2.1.21) were overexpressed in Escherichia coli and their recombinant enzymes (egl-FZYE and cel-FZYE, respectively) characterized. Those genes were found in Trabulsiella odontermitis which was isolated from the gut of termite Heterotermes sp. Additionally, the capability to release sugars from agricultural wastes was evaluated in both enzymes, alone and in combination. Results The results have shown that optimal pH was 6.0 and 6.5, reaching an activity of 1051.65 ± 47.78 and 607.80 ± 10.19 U/mg at 39 °C, for egl-FZYE and cel-FZYE, respectively. The Km and Vmax for egl-FZYE using CMC as substrate were 11.25 mg/mL and 3921.57 U/mg, respectively, whereas using Avicel were 15.39 mg/mL and 2314.81 U/mg, respectively. The Km and Vmax for cel-FZYE using Avicel as substrate were 11.49 mg/mL and 2105.26 U/mg, respectively, whereas using CMC the enzyme did not had activity. Both enzymes had effect on agricultural wastes, and their effect was improved when they were combined reaching an activity of 955.1 ± 116.1, 4016.8 ± 332 and 1124.2 ± 241 U/mg on corn stover, sorghum stover and pine sawdust, respectively. Conclusions Both enzymes were capable of degrading agricultural wastes, and their effectiveness was improved up to 60% of glucose released when combined. In summary, the results of the study demonstrate that the recombinant enzymes exhibit characteristics that indicate their value as potential feed additives and that the enzymes could be used to enhance the degradation of cellulose in the poor-quality forage generally used in ruminant feedstuffs. Supplementary Information The online version contains supplementary material available at 10.1186/s12896-021-00687-6.
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Affiliation(s)
- Martha María Arevalos-Sánchez
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - Adrián Omar Maynez-Perez
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - Felipe A Rodríguez-Almeida
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - José Alfredo Martínez-Quintana
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - Fidel Alejandro Sanchez-Flores
- Unidad de Secuenciación Masiva y Bioinformática, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Monserrath Felix-Portillo
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - América Chavéz-Martínez
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - Myrna Elena Olvera-García
- Unidad de Secuenciación Masiva y Bioinformática, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Oscar Ruiz-Barrera
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico
| | - Agustín Corral-Luna
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Periférico Francisco R. Almada Km 1, 31453, Chihuahua, Mexico.
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Lupinus albus γ-Conglutin, a Protein Structurally Related to GH12 Xyloglucan-Specific Endo-Glucanase Inhibitor Proteins (XEGIPs), Shows Inhibitory Activity against GH2 β-Mannosidase. Int J Mol Sci 2020; 21:ijms21197305. [PMID: 33022933 PMCID: PMC7583008 DOI: 10.3390/ijms21197305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
γ-conglutin (γC) is a major protein of Lupinus albus seeds, but its function is still unknown. It shares high structural similarity with xyloglucan-specific endo-glucanase inhibitor proteins (XEGIPs) and, to a lesser extent, with Triticum aestivum endoxylanase inhibitors (TAXI-I), active against fungal glycoside hydrolases GH12 and GH11, respectively. However, γC lacks both these inhibitory activities. Since β-galactomannans are major components of the cell walls of endosperm in several legume plants, we tested the inhibitory activity of γC against a GH2 β-mannosidase (EC 3.2.1.25). γC was actually able to inhibit the enzyme, and this effect was enhanced by the presence of zinc ions. The stoichiometry of the γC/enzyme interaction was 1:1, and the calculated Ki was 1.55 μM. To obtain further insights into the interaction between γC and β-mannosidase, an in silico structural bioinformatic approach was followed, including some docking analyses. By and large, this work describes experimental findings that highlight new scenarios for understanding the natural role of γC. Although structural predictions can leave space for speculative interpretations, the full complexity of the data reported in this work allows one to hypothesize mechanisms of action for the basis of inhibition. At least two mechanisms seem plausible, both involving lupin-γC-peculiar structures.
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Suleiman M, Krüger A, Antranikian G. Biomass-degrading glycoside hydrolases of archaeal origin. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:153. [PMID: 32905355 PMCID: PMC7469102 DOI: 10.1186/s13068-020-01792-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
During the last decades, the impact of hyperthermophiles and their enzymes has been intensively investigated for implementation in various high-temperature biotechnological processes. Biocatalysts of hyperthermophiles have proven to show extremely high thermo-activities and thermo-stabilities and are identified as suitable candidates for numerous industrial processes with harsh conditions, including the process of an efficient plant biomass pretreatment and conversion. Already-characterized archaea-originated glycoside hydrolases (GHs) have shown highly impressive features and numerous enzyme characterizations indicated that these biocatalysts show maximum activities at a higher temperature range compared to bacterial ones. However, compared to bacterial biomass-degrading enzymes, the number of characterized archaeal ones remains low. To discover new promising archaeal GH candidates, it is necessary to study in detail the microbiology and enzymology of extremely high-temperature habitats, ranging from terrestrial to marine hydrothermal systems. State-of-the art technologies such as sequencing of genomes and metagenomes and automated binning of genomes out of metagenomes, combined with classical microbiological culture-dependent approaches, have been successfully performed to detect novel promising biomass-degrading hyperthermozymes. In this review, we will focus on the detection, characterization and similarities of archaeal GHs and their unique characteristics. The potential of hyperthermozymes and their impact on high-temperature industrial applications have not yet been exhausted.
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Affiliation(s)
- Marcel Suleiman
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Anna Krüger
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
| | - Garabed Antranikian
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
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Dorival J, Philys S, Giuntini E, Brailly R, de Ruyck J, Czjzek M, Biondi E, Bompard C. Structural and enzymatic characterisation of the Type III effector NopAA (=GunA) from Sinorhizobium fredii USDA257 reveals a Xyloglucan hydrolase activity. Sci Rep 2020; 10:9932. [PMID: 32555346 PMCID: PMC7303141 DOI: 10.1038/s41598-020-67069-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 04/28/2020] [Indexed: 12/03/2022] Open
Abstract
Rhizobia are nitrogen-fixing soil bacteria that can infect legume plants to establish root nodules symbiosis. To do that, a complex exchange of molecular signals occurs between plants and bacteria. Among them, rhizobial Nops (Nodulation outer proteins), secreted by a type III secretion system (T3SS) determine the host-specificity for efficient symbiosis with plant roots. Little is known about the molecular function of secreted Nops (also called effectors (T3E)) and their role in the symbiosis process. We performed the structure-function characterization of NopAA, a T3E from Sinorhizobium fredii by using a combination of X-ray crystallography, biochemical and biophysical approaches. This work displays for the first time a complete structural and biochemical characterization of a symbiotic T3E. Our results showed that NopAA has a catalytic domain with xyloglucanase activity extended by a N-terminal unfolded secretion domain that allows its secretion. We proposed that these original structural properties combined with the specificity of NopAA toward xyloglucan, a key component of root cell wall which is also secreted by roots in the soil, can give NopAA a strategic position to participate in recognition between bacteria and plant roots and to intervene in nodulation process.
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Affiliation(s)
- Jonathan Dorival
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680, Roscoff, Bretagne, France
| | - Sonia Philys
- CNRS, Univ. Lille, Unité de Glycobiologie Structurale et Fonctionnelle, 59000, Lille, France
| | - Elisa Giuntini
- CNRS, Univ. Lille, Unité de Glycobiologie Structurale et Fonctionnelle, 59000, Lille, France
| | - Romain Brailly
- CNRS, Univ. Lille, Unité de Glycobiologie Structurale et Fonctionnelle, 59000, Lille, France
| | - Jérôme de Ruyck
- CNRS, Univ. Lille, Unité de Glycobiologie Structurale et Fonctionnelle, 59000, Lille, France
| | - Mirjam Czjzek
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680, Roscoff, Bretagne, France
| | | | - Coralie Bompard
- CNRS, Univ. Lille, Unité de Glycobiologie Structurale et Fonctionnelle, 59000, Lille, France.
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Rykov SV, Kornberger P, Herlet J, Tsurin NV, Zorov IN, Zverlov VV, Liebl W, Schwarz WH, Yarotsky SV, Berezina OV. Novel endo-(1,4)-β-glucanase Bgh12A and xyloglucanase Xgh12B from Aspergillus cervinus belong to GH12 subgroup I and II, respectively. Appl Microbiol Biotechnol 2019; 103:7553-7566. [PMID: 31332485 DOI: 10.1007/s00253-019-10006-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/24/2019] [Accepted: 06/30/2019] [Indexed: 12/15/2022]
Abstract
In spite of intensive exploitation of aspergilli for the industrial production of carbohydrases, little is known about hydrolytic enzymes of fungi from the section Cervini. Novel glycoside hydrolases Bgh12A and Xgh12B from Aspergillus cervinus represent examples of divergent activities within one enzyme family and belong to the GH12 phylogenetic subgroup I (endo-(1,4)-β-glucanases) and II (endo-xyloglucanases), respectively. The bgh12A and xgh12B genes were identified in the unsequenced genome of A. cervinus using primers designed for conservative regions of the corresponding subgroups and a genome walking approach. The recombinant enzymes were heterologously produced in Pichia pastoris, purified, and characterized. Bgh12A was an endo-(1,4)-β-glucanase (EC 3.2.1.4) hydrolyzing the unbranched soluble β-(1,4)-glucans and mixed linkage β-(1,3;1,4)-D-glucans. Bgh12A exhibited maximum activity on barley β-glucan (BBG), which amounted to 614 ± 30 U/mg of protein. The final products of BBG and lichenan hydrolysis were glucose, cellobiose, cellotriose, 4-O-β-laminaribiosyl-glucose, and a range of higher mixed-linkage gluco-oligosaccharides. In contrast, the activity of endo-xyloglucanase Xgh12B (EC 3.2.1.151) was restricted to xyloglucan, with 542 ± 39 U/mg protein. The enzyme cleaved the (1,4)-β-glycosidic bonds of the xyloglucan backbone at the unsubstituted glucose residues finally generating cellotetraose-based hepta-, octa, and nona-oligosaccharides. Bgh12A and Xgh12B had maximal activity at 55 °C, pH 5.0. At these conditions, the half-time of Xgh12B inactivation was 158 min, whereas the half-life of Bgh12A was 5 min. Recombinant P. pastoris strains produced up to 106 U/L of the target enzymes with at least 75% of recombinant protein in the total extracellular proteins. The Bgh12A and Xgh12B sequences show 43% identity. Strict differences in substrate specificity of Bgh12A and Xgh12B were in congruence with the presence of subgroup-specific structural loops and substrate-binding aromatic residues in the catalytic cleft of the enzymes. Individual composition of aromatic residues in the catalytic cleft defined variability in substrate selectivity within GH12 subgroups I and II.
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Affiliation(s)
- Sergey V Rykov
- State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center «Kurchatov Institute», 1-st Dorozhniy pr. 1, Moscow, Russian Federation, 117545
| | - Petra Kornberger
- Department of Microbiology, Technical University Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | - Jonathan Herlet
- Department of Microbiology, Technical University Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | - Nikita V Tsurin
- State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center «Kurchatov Institute», 1-st Dorozhniy pr. 1, Moscow, Russian Federation, 117545
| | - Ivan N Zorov
- Russian Academy of Sciences, Federal Research Centre "Fundamentals of Biotechnology", Leninsky prospect, 33, build. 2, Moscow, 119071, Russian Federation
| | - Vladimir V Zverlov
- Department of Microbiology, Technical University Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
- Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 2, Moscow, Russian Federation, 123182
| | - Wolfgang Liebl
- Department of Microbiology, Technical University Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | - Wolfgang H Schwarz
- Department of Microbiology, Technical University Munich, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | - Sergey V Yarotsky
- State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center «Kurchatov Institute», 1-st Dorozhniy pr. 1, Moscow, Russian Federation, 117545
| | - Oksana V Berezina
- State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center «Kurchatov Institute», 1-st Dorozhniy pr. 1, Moscow, Russian Federation, 117545.
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Patel AK, Singhania RR, Sim SJ, Pandey A. Thermostable cellulases: Current status and perspectives. BIORESOURCE TECHNOLOGY 2019; 279:385-392. [PMID: 30685132 DOI: 10.1016/j.biortech.2019.01.049] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 05/18/2023]
Abstract
It is envisaged that the utilization of lignocellulosic biomass for ethanol production for transport sector, would make cellulases the most demanded industrial enzyme. The greatest potential of cellulolytic enzymes lies in ethanol production from biomass by enzymatic hydrolysis of cellulose but low thermostability and low titer of cellulase production resulting into high cost of the enzyme which is the major set-back. A number of research groups are working on cellulase to improve its thermostability so as to be able to perform hydrolysis at elevated temperatures which would eventually increase the efficiency of cellulose hydrolysis. The technologies developed from lignocellulosic biomass via cellulose hydrolysis promise environmental and economical sustainability in the long run along with non-dependence on nonrenewable energy source. This review deals with the important sources of thermostable cellulases, mechanism, its regulation, strategies to enhance the thermostability further with respect to its importance for biofuel applications.
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Affiliation(s)
- Anil K Patel
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | | | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, Indian Institute of Toxicological Research, Lucknow 226 001, India
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de Paula RG, Antoniêto ACC, Ribeiro LFC, Srivastava N, O'Donovan A, Mishra PK, Gupta VK, Silva RN. Engineered microbial host selection for value-added bioproducts from lignocellulose. Biotechnol Adv 2019; 37:107347. [PMID: 30771467 DOI: 10.1016/j.biotechadv.2019.02.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 01/27/2019] [Accepted: 02/08/2019] [Indexed: 12/12/2022]
Abstract
Lignocellulose is a rich and sustainable globally available carbon source and is considered a prominent alternative raw material for producing biofuels and valuable chemical compounds. Enzymatic hydrolysis is one of the crucial steps of lignocellulose degradation. Cellulolytic and hemicellulolytic enzyme mixes produced by different microorganisms including filamentous fungi, yeasts and bacteria, are used to degrade the biomass to liberate monosaccharides and other compounds for fermentation or conversion to value-added products. During biomass pretreatment and degradation, toxic compounds are produced, and undesirable carbon catabolic repression (CCR) can occur. In order to solve this problem, microbial metabolic pathways and transcription factors involved have been investigated along with the application of protein engineering to optimize the biorefinery platform. Engineered Microorganisms have been used to produce specific enzymes to breakdown biomass polymers and metabolize sugars to produce ethanol as well other biochemical compounds. Protein engineering strategies have been used for modifying lignocellulolytic enzymes to overcome enzymatic limitations and improving both their production and functionality. Furthermore, promoters and transcription factors, which are key proteins in this process, are modified to promote microbial gene expression that allows a maximum performance of the hydrolytic enzymes for lignocellulosic degradation. The present review will present a critical discussion and highlight the aspects of the use of microorganisms to convert lignocellulose into value-added bioproduct as well combat the bottlenecks to make the biorefinery platform from lignocellulose attractive to the market.
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Affiliation(s)
- Renato Graciano de Paula
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Liliane Fraga Costa Ribeiro
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Neha Srivastava
- Department of Chemical Engineering & Technology, IIT (BHU), Varanasi 221005, U.P, India
| | - Anthonia O'Donovan
- School of Science and Computing, Galway-Mayo Institute of Technology, Galway, Ireland
| | - P K Mishra
- Department of Chemical Engineering & Technology, IIT (BHU), Varanasi 221005, U.P, India
| | - Vijai K Gupta
- ERA Chair of Green Chemistry, Department of Chemistry and Biotechnology, Tallinn University of Technology, 12618 Tallinn, Estonia.
| | - Roberto N Silva
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
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Waghmare PR, Patil SM, Jadhav SL, Jeon BH, Govindwar SP. Utilization of agricultural waste biomass by cellulolytic isolate Enterobacter sp. SUK-Bio. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.anres.2018.10.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Qu W, Lin D, Zhang Z, Di W, Gao B, Zeng R. Metagenomics Investigation of Agarlytic Genes and Genomes in Mangrove Sediments in China: A Potential Repertory for Carbohydrate-Active Enzymes. Front Microbiol 2018; 9:1864. [PMID: 30177916 PMCID: PMC6109693 DOI: 10.3389/fmicb.2018.01864] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/25/2018] [Indexed: 12/31/2022] Open
Abstract
Monosaccharides and oligosaccharides produced by agarose degradation exhibit potential in the fields of bioenergy, medicine, and cosmetics. Mangrove sediments (MGSs) provide a special environment to enrich enzymes for agarose degradation. However, representative investigations of the agarlytic genes in MGSs have been rarely reported. In this study, agarlytic genes in MGSs were researched in detail from the aspects of diversity, abundance, activity, and location through deep metagenomics sequencing. Functional genes in MGSs were usually incomplete but were shown as results, which could cause virtually high number of results in previous studies because multiple fragmented sequences could originate from the same genes. In our work, only complete and nonredundant (CNR) genes were analyzed to avoid virtually high amount of the results. The number of CNR agarlytic genes in our datasets was significantly higher than that in the datasets of previous studies. Twenty-one recombinant agarases with agarose-degrading activity were detected using heterologous expression based on numerous complete open-reading frames, which are rarely obtained in metagenomics sequencing of samples with complex microbial communities, such as MGSs. Aga2, which had the highest crude enzyme activity among the 21 recombinant agarases, was further purified and subjected to enzymatic characterization. With its high agarose-degrading activity, resistance to temperature changes and chemical agents, Aga2 could be a suitable option for industrial production. The agarase ratio with signal peptides to that without signal peptides in our MGS datasets was lower than that of other reported agarases. Six draft genomes, namely, Clusters 1-6, were recovered from the datasets. The taxonomic annotation of these genomes revealed that Clusters 1, 3, 5, and 6 were annotated as Desulfuromonas sp., Treponema sp., Ignavibacteriales spp., and Polyangiaceae spp., respectively. Meanwhile, Clusters 2 and 4 were potential new species. All these genomes were first reported and found to have abilities of degrading various important polysaccharides. The metabolic pathway of agarose in Cluster 4 was also speculated. Our results showed the capacity and activity of agarases in the MGS microbiome, and MGSs exert potential as a repertory for mining not only agarlytic genes but also almost all genes of the carbohydrate-active enzyme family.
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Affiliation(s)
- Wu Qu
- School of Life Sciences, Xiamen University, Xiamen, China
| | - Dan Lin
- Novogene Bioinformatics Technology Co. Ltd., Tianjin, China
| | - Zhouhao Zhang
- Novogene Bioinformatics Technology Co. Ltd., Tianjin, China
| | - Wenjie Di
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, China
| | - Boliang Gao
- School of Life Sciences, Xiamen University, Xiamen, China
| | - Runying Zeng
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, China.,Key Laboratory of Marine Genetic Resources, Xiamen, China
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Escuder-Rodríguez JJ, DeCastro ME, Cerdán ME, Rodríguez-Belmonte E, Becerra M, González-Siso MI. Cellulases from Thermophiles Found by Metagenomics. Microorganisms 2018; 6:microorganisms6030066. [PMID: 29996513 PMCID: PMC6165527 DOI: 10.3390/microorganisms6030066] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/04/2018] [Accepted: 07/05/2018] [Indexed: 01/05/2023] Open
Abstract
Cellulases are a heterogeneous group of enzymes that synergistically catalyze the hydrolysis of cellulose, the major component of plant biomass. Such reaction has biotechnological applications in a broad spectrum of industries, where they can provide a more sustainable model of production. As a prerequisite for their implementation, these enzymes need to be able to operate in the conditions the industrial process requires. Thus, cellulases retrieved from extremophiles, and more specifically those of thermophiles, are likely to be more appropriate for industrial needs in which high temperatures are involved. Metagenomics, the study of genes and gene products from the whole community genomic DNA present in an environmental sample, is a powerful tool for bioprospecting in search of novel enzymes. In this review, we describe the cellulolytic systems, we summarize their biotechnological applications, and we discuss the strategies adopted in the field of metagenomics for the discovery of new cellulases, focusing on those of thermophilic microorganisms.
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Affiliation(s)
- Juan-José Escuder-Rodríguez
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Eugenia DeCastro
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Esperanza Cerdán
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - Esther Rodríguez-Belmonte
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - Manuel Becerra
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Isabel González-Siso
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
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15
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MARECIK ROMAN, BŁASZCZYK LIDIA, BIEGAŃSKA-MARECIK RÓŻA, PIOTROWSKA-CYPLIK AGNIESZKA. Screening and Identification of Trichoderma Strains Isolated from Natural Habitats with Potential to Cellulose and Xylan Degrading Enzymes Production. Pol J Microbiol 2018; 67:181-190. [PMID: 30015456 PMCID: PMC7256729 DOI: 10.21307/pjm-2018-021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 12/27/2017] [Accepted: 02/02/2018] [Indexed: 12/13/2022] Open
Abstract
A total of 123 Trichoderma strains were isolated from different habitats and tested for their ability to degrade cellulose and xylan by simple plate screening method. Among strains, more than 34 and 45% respectively, exhibited higher cellulolytic and xylanolytic activity, compared to the reference strain T. reesei QM 9414. For strains efficiently degrading cellulose, a highest enzyme activity was confirmed using filter paper test, and it resulted in a range from 1.01 to 7.15 FPU/ml. Based on morphological and molecular analysis, the isolates were identified as Trichoderma. The most frequently identified strains belonged to Trichoderma harzianum species. Among all strains, the most effective in degradation of cellulose and xylose was T. harzianum and T. virens, especially those isolated from forest wood, forest soil or garden and mushroom compost. The results of this work confirmed that numerous strains from the Trichoderma species have high cellulose and xylan degradation potential and could be useful for lignocellulose biomass conversion e.g. for biofuel production.
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Affiliation(s)
- ROMAN MARECIK
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, Poznań, Poland
| | - LIDIA BŁASZCZYK
- Institute of Plant Genetics, Polish Academy of Sciences, Poznań, Poland
| | - RÓŻA BIEGAŃSKA-MARECIK
- Institute of Food Technology of Plant Origin, Poznań University of Life Sciences, Poznań, Poland
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Paramjeet S, Manasa P, Korrapati N. Biofuels: Production of fungal-mediated ligninolytic enzymes and the modes of bioprocesses utilizing agro-based residues. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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17
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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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Loop 3 of Fungal Endoglucanases of Glycoside Hydrolase Family 12 Modulates Catalytic Efficiency. Appl Environ Microbiol 2017; 83:AEM.03123-16. [PMID: 28039140 DOI: 10.1128/aem.03123-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 12/28/2016] [Indexed: 01/25/2023] Open
Abstract
Glycoside hydrolase (GH) family 12 comprises enzymes with a wide range of activities critical for the degradation of lignocellulose. However, the important roles of the loop regions of GH12 enzymes in substrate specificity and catalytic efficiency remain poorly understood. This study examined how the loop 3 region affects the enzymatic properties of GH12 glucanases using NfEG12A from Neosartorya fischeri P1 and EG (PDB 1KS4) from Aspergillus niger Acidophilic and thermophilic NfEG12A had the highest catalytic efficiency (kcat/Km , 3,001 and 263 ml/mg/s toward lichenin and carboxymethyl cellulose sodium [CMC-Na], respectively) known so far. Based on the multiple-sequence alignment and homology modeling, two specific sequences (FN and STTQA) were identified in the loop 3 region of GH12 endoglucanases from fungi. To determine their functions, these sequences were introduced into NfEG12A, or the counterpart sequence STTQA was removed from EG. These modifications had no effects on the optimal pH and temperature or substrate specificity but changed the catalytic efficiency (kcat/Km ) of these enzymes (in descending order, NfEG12A [100%], NfEG12A-FN [140%], and NfEG12A-STTQA [190%]; EG [100%] and EGΔSTTQA [41%]). Molecular docking and dynamic simulation analyses revealed that the longer loop 3 in GH12 may strengthen the hydrogen-bond interactions between the substrate and protein, thereby increasing the turnover rate (kcat). This study provides a new insight to understand the vital roles of loop 3 for GH12 endoglucanases in catalysis.IMPORTANCE Loop structures play critical roles in the substrate specificity and catalytic hydrolysis of GH12 enzymes. Three typical loops exist in these enzymes. Loops 1 and 2 are recognized as the catalytic loops and are closely related to the substrate specificity and catalytic efficiency. Loop 3 locates in the -1 or +1 subsite and varies a lot in amino acid composition, which may play a role in catalysis. In this study, two GH12 glucanases, NfEG12A and EG, which were mutated by introducing or deleting partial loop 3 sequences FN and/or STTQA, were selected to identify the function of loop 3. It revealed that the longer loop 3 of GH12 glucanases may strengthen the hydrogen network interactions between the substrate and protein, consequently increasing the turnover rate (kcat). This study proposes a strategy to increase the catalytic efficiency of GH12 glucanases by improving the hydrogen network between substrates and catalytic loops.
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Ben Hmad I, Boudabbous M, Belghith H, Gargouri A. A novel ionic liquid-stable halophilic endoglucanase from Stachybotrys microspora. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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20
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Jiang X, Li W, Chen G, Wang L. Dynamic Perturbation of the Active Site Determines Reversible Thermal Inactivation in Glycoside Hydrolase Family 12. J Chem Inf Model 2017; 57:288-297. [DOI: 10.1021/acs.jcim.6b00692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xukai Jiang
- State Key Laboratory
of Microbial
Technology, Shandong University, Jinan 250100, China
| | - Wen Li
- State Key Laboratory
of Microbial
Technology, Shandong University, Jinan 250100, China
| | - Guanjun Chen
- State Key Laboratory
of Microbial
Technology, Shandong University, Jinan 250100, China
| | - Lushan Wang
- State Key Laboratory
of Microbial
Technology, Shandong University, Jinan 250100, China
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21
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Segato F, Dias B, Berto GL, de Oliveira DM, De Souza FHM, Citadini AP, Murakami MT, Damásio ARL, Squina FM, Polikarpov I. Cloning, heterologous expression and biochemical characterization of a non-specific endoglucanase family 12 from Aspergillus terreus NIH2624. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:395-403. [PMID: 28088615 DOI: 10.1016/j.bbapap.2017.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/20/2016] [Accepted: 01/06/2017] [Indexed: 01/30/2023]
Abstract
The cellulases from Glycoside Hydrolyses family 12 (GH12) play an important role in cellulose degradation and plant cell wall deconstruction being widely used in a number of bioindustrial processes. Aiming to contribute toward better comprehension of these class of the enzymes, here we describe a high-yield secretion of a endoglucanase GH12 from Aspegillus terreus (AtGH12), which was cloned and expressed in Aspergillus nidulans strain A773. The purified protein was used for complete biochemical and functional characterization. The optimal temperature and pH of the enzyme were 55°C and 5.0 respectively, which has high activity against β-glucan and xyloglucan and also is active toward glucomannan and CMC. The enzyme retained activity up to 60°C. AtGH12 is strongly inhibited by Cu2+, Fe2+, Cd2+, Mn2+, Ca2+, Zn2+ and EDTA, whereas K+, Tween, Cs+, DMSO, Triton X-100 and Mg2+ enhanced the enzyme activity. Furthermore, SAXS data reveal that the enzyme has a globular shape and CD analysis demonstrated a prevalence of a β-strand structure corroborating with typical β-sheets fold commonly found for other endoglucanases from GH12 family.
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Affiliation(s)
- Fernando Segato
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil; Departamento de Biotecnologia, Escola de Engenharia de Lorena - Universidade de São Paulo, Lorena, SP, Brazil
| | - Bruno Dias
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Gabriela L Berto
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil; Departamento de Biotecnologia, Escola de Engenharia de Lorena - Universidade de São Paulo, Lorena, SP, Brazil
| | - Dyoni M de Oliveira
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Flávio H M De Souza
- Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Ana Paula Citadini
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Mario T Murakami
- Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - André R L Damásio
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Fábio Márcio Squina
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP, Brazil
| | - Igor Polikarpov
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil.
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22
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A novel proteomics sample preparation method for secretome analysis of Hypocrea jecorina growing on insoluble substrates. J Proteomics 2016; 131:104-112. [DOI: 10.1016/j.jprot.2015.10.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 09/21/2015] [Accepted: 10/12/2015] [Indexed: 11/23/2022]
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23
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Jiang X, Chen G, Wang L. Structural and dynamic evolution of the amphipathic N-terminus diversifies enzyme thermostability in the glycoside hydrolase family 12. Phys Chem Chem Phys 2016; 18:21340-50. [DOI: 10.1039/c6cp02998a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The N-terminus diversifies enzyme thermostability in the GH12 family, which was investigated by MD simulations, and provides potential applications in protein engineering.
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Affiliation(s)
- Xukai Jiang
- State Key Laboratory of Microbial Technology
- Shandong University
- Jinan 250100
- China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology
- Shandong University
- Jinan 250100
- China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology
- Shandong University
- Jinan 250100
- China
- State Key Laboratory of Biochemical Engineering
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Zhang X, Wang S, Wu X, Liu S, Li D, Xu H, Gao P, Chen G, Wang L. Subsite-specific contributions of different aromatic residues in the active site architecture of glycoside hydrolase family 12. Sci Rep 2015; 5:18357. [PMID: 26670009 PMCID: PMC4680936 DOI: 10.1038/srep18357] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/16/2015] [Indexed: 01/22/2023] Open
Abstract
The active site architecture of glycoside hydrolase (GH) is a contiguous subregion of the enzyme constituted by residues clustered in the three-dimensional space, recognizing the monomeric unit of ligand through hydrogen bonds and hydrophobic interactions. Mutations of the key residues in the active site architecture of the GH12 family exerted different impacts on catalytic efficiency. Binding affinities between the aromatic amino acids and carbohydrate rings were quantitatively determined by isothermal titration calorimetry (ITC) and the quantum mechanical (QM) method, showing that the binding capacity order of Tyr>Trp>His (and Phe) was determined by their side-chain properties. The results also revealed that the binding constant of a certain residue remained unchanged when altering its location, while the catalytic efficiency changed dramatically. Increased binding affinity at a relatively distant subsite, such as the mutant of W7Y at the -4 subsite, resulted in a marked increase in the intermediate product of cellotetraose and enhanced the reactivity of endoglucanase by 144%; while tighter binding near the catalytic center, i.e. W22Y at the -2 subsite, enabled the enzyme to bind and hydrolyze smaller oligosaccharides. Clarification of the specific roles of the aromatics at different subsites may pave the way for a more rational design of GHs.
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Affiliation(s)
- Xiaomei Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Shuai Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Xiuyun Wu
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Shijia Liu
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Dandan Li
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Hao Xu
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100, P.R. China
| | - Peiji Gao
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Guanjun Chen
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Lushan Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
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25
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Wang J, Gao G, Li Y, Yang L, Liang Y, Jin H, Han W, Feng Y, Zhang Z. Cloning, Expression, and Characterization of a Thermophilic Endoglucanase, AcCel12B from Acidothermus cellulolyticus 11B. Int J Mol Sci 2015; 16:25080-95. [PMID: 26506341 PMCID: PMC4632791 DOI: 10.3390/ijms161025080] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/29/2015] [Accepted: 10/13/2015] [Indexed: 12/23/2022] Open
Abstract
The gene ABK52392 from the thermophilic bacterium Acidothermus cellulolyticus 11B was predicted to be endoglucanase and classified into glycoside hydrolase family 12. ABK52392 encodes a protein containing a catalytic domain and a carbohydrate binding module. ABK52392 was cloned and functionally expressed in Escherichia coli. After purification by Ni-NTA agarose affinity chromatography and Q-Sepharose® Fast Flow chromatography, the properties of the recombinant protein (AcCel12B) were characterized. AcCel12B exhibited optimal activity at pH 4.5 and 75 °C. The half-lives of AcCel12B at 60 and 70 °C were about 90 and 2 h, respectively, under acidic conditions. The specific hydrolytic activities of AcCel12B at 70 °C and pH 4.5 for sodium carboxymethylcellulose (CMC) and regenerated amorphous cellulose (RAC) were 118.3 and 104.0 U·mg−1, respectively. The Km and Vmax of AcCel12B for CMC were 25.47 mg·mL−1 and 131.75 U·mg−1, respectively. The time course of hydrolysis for RAC was investigated by measuring reducing ends in the soluble and insoluble phases. The total hydrolysis rate rapidly decreased after the early stage of incubation and the generation of insoluble reducing ends decreased earlier than that of soluble reducing ends. High thermostability of the cellulase indicates its potential commercial significance and it could be exploited for industrial application in the future.
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Affiliation(s)
- Junling Wang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
- Department of Biotechnology, Jilin Agricultural Science and Technology College, Jilin 132101, China.
| | - Gui Gao
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yuwei Li
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
| | - Liangzhen Yang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yanli Liang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Hanyong Jin
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Weiwei Han
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yan Feng
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Zuoming Zhang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
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Zhang J, Shi H, Xu L, Zhu X, Li X. Site-Directed Mutagenesis of a Hyperthermophilic Endoglucanase Cel12B from Thermotoga maritima Based on Rational Design. PLoS One 2015. [PMID: 26218520 PMCID: PMC4517919 DOI: 10.1371/journal.pone.0133824] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
To meet the demand for the application of high activity and thermostable cellulases in the production of new-generation bioethanol from nongrain-cellulose sources, a hyperthermostable β-1,4-endoglucase Cel12B from Thermotoga maritima was selected for further modification by gene site-directed mutagenesis method in the present study, based on homology modeling and rational design. As a result, two recombinant enzymes showed significant improvement in enzyme activity by 77% and 87%, respectively, higher than the parental enzyme TmCel12B. Furthermore, the two mutants could retain 80% and 90.5% of their initial activity after incubation at 80°C for 8 h, while only 45% for 5 h to TmCel12B. The Km and Vmax of the two recombinant enzymes were 1.97±0.05 mM, 4.23±0.15 μmol·mg(-1)·min(-1) of TmCel12B-E225H-K207G-D37V, and 2.97±0.12 mM, 3.15±0.21 μmol·mg(-1)·min(-1) of TmCel12B-E225H-K207G, respectively, when using CMC-Na as the substrate. The roles of the mutation sites were also analyzed and evaluated in terms of electron density, hydrophobicity of the modeled protein structures. The recombinant enzymes may be used in the hydrolysis of cellulose at higher temperature in the future. It was concluded that the gene mutagenesis approach of a certain active residues may effectively improve the performance of cellulases for the industrial applications and contribute to the study the thermostable mechanism of thermophilic enzymes.
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Affiliation(s)
- Jinfeng Zhang
- Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- School of Life Science and Chemical Engineering, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
| | - Hao Shi
- Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
| | - Linyu Xu
- Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- School of Life Science and Chemical Engineering, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
| | - Xiaoyan Zhu
- Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- School of Life Science and Chemical Engineering, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huaian, Jiangsu 223300, P. R. China
| | - Xiangqian Li
- Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- School of Life Science and Chemical Engineering, Huaiyin Institute of Technology, Huaian, Jiangsu 223003, P. R. China
- * E-mail:
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27
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Recombinant Trichoderma harzianum endoglucanase I (Cel7B) is a highly acidic and promiscuous carbohydrate-active enzyme. Appl Microbiol Biotechnol 2015; 99:9591-604. [DOI: 10.1007/s00253-015-6772-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/09/2015] [Accepted: 06/12/2015] [Indexed: 12/11/2022]
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28
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Yu M, Qiu Y, Chen W, Zhao F, Shao J. Action modes of recombinant endocellulase, EGA, and its domains on cotton fabrics. Biotechnol Lett 2015; 37:1615-22. [PMID: 25975370 DOI: 10.1007/s10529-015-1832-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES The action modes of an endocellulase, EGA, and its domains (CD9 and CBM3) during enzymatic treatment of cotton fabrics were investigated. RESULTS EGA, CD9 and CBM3 had the binding capacity to cellulose substrates, of which the filter paper was the substrate with the strongest binding capacity. Analyses of scanning electronic microscopy indicated that EGA and its catalytic domain CD9 etched the surface of cotton fabrics and broke the fibers of long chains. On the other hand, the binding domain CBM3 only resulted in swelling of cotton fibers. Both EGA and its catalytic domain CD9 had minimal effect on the weight loss of cotton fabrics, whereas the effect of EGA and CD9 on the degree of polymerization and breaking strength was significant. After 12 h enzymatic action, the values of weight loss ratio for EGA and CD9 were 2.07 and 2.21 %, respectively, meanwhile the reductions in fabric strength were 27.04 % for EGA and 17.23 % for CD9. CONCLUSIONS In contrast to the action of EGA and CD9, CBM3 showed no significant changes in terms of the weight loss ratio, degree of polymerization, and fabric strength.
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Affiliation(s)
- Meilan Yu
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, China
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29
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Tian F, Xie ZL, Zhao LZ, Guo J, Han XB, Xie LF, Wang Y, Chang XY. Comparative secretome analysis of Fusarium sp. Q7-31T during liquid fermentation using oat straw as a carbon source. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1051-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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Okano H, Ozaki M, Kanaya E, Kim JJ, Angkawidjaja C, Koga Y, Kanaya S. Structure and stability of metagenome-derived glycoside hydrolase family 12 cellulase (LC-CelA) a homolog of Cel12A from Rhodothermus marinus. FEBS Open Bio 2014; 4:936-46. [PMID: 25426413 PMCID: PMC4239480 DOI: 10.1016/j.fob.2014.10.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 10/27/2014] [Accepted: 10/27/2014] [Indexed: 11/24/2022] Open
Abstract
Ten novel cellulases, LC-CelA–J, were isolated from leaf–branch compost by a metagenomic approach. LC-CelA was characterized. The structure, activity, and stability of LC-CelA were similar to those of Cel12A from Rhodothermus marinus. Glu34-mediated hydrogen bonds and two disulfide bonds contribute to the stabilization of LC-CelA.
Ten genes encoding novel cellulases with putative signal peptides at the N-terminus, termed pre-LC-CelA–J, were isolated from a fosmid library of a leaf–branch compost metagenome by functional screening using agar plates containing carboxymethyl cellulose and trypan blue. All the cellulases except pre-LC-CelG have a 14–29 residue long flexible linker (FL) between the signal peptide and the catalytic domain. LC-CelA without a signal peptide (residues 20–261), which shows 76% amino acid sequence identity to Cel12A from Rhodothermus marinus (RmCel12A), was overproduced in Escherichiacoli, purified and characterized. LC-CelA exhibited its highest activity across a broad pH range (pH 5–9) and at 90 °C, indicating that LC-CelA is a highly thermostable cellulase, like RmCel12A. The crystal structure of LC-CelA was determined at 1.85 Å resolution and is nearly identical to that of RmCel12A determined in a form without the FL. Both proteins contain two disulfide bonds. LC-CelA has a 16-residue FL (residues 20–35), most of which is not visible in the electron density map, probably due to structural disorder. However, Glu34 and Pro35 form hydrogen bonds with the central region of the protein. ΔFL-LC-CelA (residues 36–261) and E34A-LC-CelA with a single Glu34 → Ala mutation were therefore constructed and characterized. ΔFL-LC-CelA and E34A-LC-CelA had lower melting temperatures (Tm) than LC-CelA by 14.7 and 12.0 °C respectively. The Tm of LC-CelA was also decreased by 28.0 °C in the presence of dithiothreitol. These results suggest that Glu34-mediated hydrogen bonds and the two disulfide bonds contribute to the stabilization of LC-CelA.
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Affiliation(s)
- Hiroyuki Okano
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masashi Ozaki
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Eiko Kanaya
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Joong-Jae Kim
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Clement Angkawidjaja
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan ; International College, Osaka University, 1-30 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
| | - Yuichi Koga
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shigenori Kanaya
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Rawat R, Kumar S, Chadha BS, Kumar D, Oberoi HS. An acidothermophilic functionally active novel GH12 family endoglucanase from Aspergillus niger HO: purification, characterization and molecular interaction studies. Antonie van Leeuwenhoek 2014; 107:103-17. [DOI: 10.1007/s10482-014-0308-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 10/15/2014] [Indexed: 11/29/2022]
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33
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Mitrovic A, Flicker K, Steinkellner G, Gruber K, Reisinger C, Schirrmacher G, Camattari A, Glieder A. Thermostability improvement of endoglucanase Cel7B from Hypocrea pseudokoningii. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2013.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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34
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Damásio ARL, Rubio MV, Oliveira LC, Segato F, Dias BA, Citadini AP, Paixão DA, Squina FM. Understanding the function of conserved variations in the catalytic loops of fungal glycoside hydrolase family 12. Biotechnol Bioeng 2014; 111:1494-505. [PMID: 24578305 DOI: 10.1002/bit.25209] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 11/11/2022]
Abstract
Enzymes that cleave the xyloglucan backbone at unbranched glucose residues have been identified in GH families 5, 7, 12, 16, 44, and 74. Fungi produce enzymes that populate 20 of 22 families that are considered critical for plant biomass deconstruction. We searched for GH12-encoding genes in 27 Eurotiomycetes genomes. After analyzing 50 GH12-related sequences, the conserved variations of the amino acid sequences were examined. Compared to the endoglucanases, the endo-xyloglucanase-associated YSG deletion at the negative subsites of the catalytic cleft with a SST insertion at the reducing end of the substrate-binding crevice is highly conserved. In addition, a highly conserved alanine residue was identified in all xyloglucan-specific enzymes, and this residue is substituted by arginine in more promiscuous glucanases. To understand the basis for the xyloglucan specificity displayed by certain GH12 enzymes, two fungal GH12 endoglucanases were chosen for mutagenesis and functional studies: an endo-xyloglucanase from Aspergillus clavatus (AclaXegA) and an endoglucanase from A. terreus (AtEglD). Comprehensive molecular docking studies and biochemical analyses were performed, revealing that mutations at the entrance of the catalytic cleft in AtEglD result in a wider binding cleft and the alteration of the substrate-cleavage pattern, implying that a trio of residues coordinates the interactions and binding to linear glycans. The loop insertion at the crevice-reducing end of AclaXegA is critical for catalytic efficiency to hydrolyze xyloglucan. The understanding of the structural elements governing endo-xyloglucanase activity on linear and branched glucans will facilitate future enzyme modifications with potential applications in industrial biotechnology.
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Affiliation(s)
- André R L Damásio
- 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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He J, Wu AM, Chen D, Yu B, Mao X, Zheng P, Yu J, Tian G. Cost-effective lignocellulolytic enzyme production by Trichoderma reesei on a cane molasses medium. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:43. [PMID: 24655817 PMCID: PMC3997213 DOI: 10.1186/1754-6834-7-43] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 03/11/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND Cane molasses, an important residue of the sugar industry, have the potential as a cost-effective carbon source that could serve as nutrients for industrial enzyme-producing microorganisms, especially filamentous fungi. However, the enzyme mixtures produced in such a complex medium are poorly characterized. In this study, the secretome of Trichoderma reesei grown on a cane molasses medium (CMM) as well as on a lactose-based conventional medium (LCM) were compared and analyzed by using proteomics. RESULTS In this study we show that both the CMM and LCM can serve as excellent growth media for T. reesei. The enzyme expression patterns in the two media were similar and a considerable number of the identified proteins on two-dimensional gel electrophoresis (2-DE) gels were those involved in biomass degradation. The most abundant cellulolytic enzymes identified in both media were cellobiohydrolases (Cel7A/Cel6A) and endoglucanases (Cel7A/Cel5A) and were found to be more abundant in CMM. We also found that both media can serve as an inducer of xylanolytic enzymes. The main xylanases (XYNI/XYNIV) and xyloglucanase (Cel74A) were found at higher concentrations in the CMM than LCM. CONCLUSIONS We analyzed the prevalent proteins secreted by T. reesei in the CMM and LCM. Here, we show that hydrolytic enzymes are cost-effective and can be produced on cane molasses as a carbon source which can be used to digest lignocellulolytic biomass.
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Affiliation(s)
- Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Ai-min Wu
- College of Forestry, South China Agricultural University, Guangzhou 510642, People’s Republic of China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Xiangbing Mao
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
| | - Gang Tian
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya’an, Sichuan 625014, People’s Republic of China
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36
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Cunha ES, Hatem CL, Barrick D. Insertion of endocellulase catalytic domains into thermostable consensus ankyrin scaffolds: effects on stability and cellulolytic activity. Appl Environ Microbiol 2013; 79:6684-96. [PMID: 23974146 PMCID: PMC3811507 DOI: 10.1128/aem.02121-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/21/2013] [Indexed: 11/20/2022] Open
Abstract
Degradation of cellulose for biofuels production holds promise in solving important environmental and economic problems. However, the low activities (and thus high enzyme-to-substrate ratios needed) of hydrolytic cellulase enzymes, which convert cellulose into simple sugars, remain a major barrier. As a potential strategy to stabilize cellulases and enhance their activities, we have embedded cellulases of extremophiles into hyperstable α-helical consensus ankyrin domain scaffolds. We found the catalytic domains CelA (CA, GH8; Clostridium thermocellum) and Cel12A (C12A, GH12; Thermotoga maritima) to be stable in the context of the ankyrin scaffold and to be active against both soluble and insoluble substrates. The ankyrin repeats in each fusion are folded, although it appears that for the C12A catalytic domain (CD; where the N and C termini are distant in the crystal structure), the two flanking ankyrin domains are independent, whereas for CA (where termini are close), the flanking ankyrin domains stabilize each other. Although the activity of CA is unchanged in the context of the ankyrin scaffold, the activity of C12A is increased between 2- and 6-fold (for regenerated amorphous cellulose and carboxymethyl cellulose substrates) at high temperatures. For C12A, activity increases with the number of flanking ankyrin repeats. These results showed ankyrin arrays to be a promising scaffold for constructing designer cellulosomes, preserving or enhancing enzymatic activity and retaining thermostability. This modular architecture will make it possible to arrange multiple cellulase domains at a precise spacing within a single polypeptide, allowing us to search for spacings that may optimize reactivity toward the repetitive cellulose lattice.
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Affiliation(s)
- Eva S. Cunha
- Institute for Multiscale Modeling of Biological Interactions, Johns Hopkins University, Baltimore, Maryland, USA
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Christine L. Hatem
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Doug Barrick
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
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Li Y, Peng X, Chen H. Comparative characterization of proteins secreted by Neurospora sitophila in solid-state and submerged fermentation. J Biosci Bioeng 2013; 116:493-8. [DOI: 10.1016/j.jbiosc.2013.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 03/05/2013] [Accepted: 04/01/2013] [Indexed: 10/26/2022]
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38
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Hori C, Gaskell J, Igarashi K, Samejima M, Hibbett D, Henrissat B, Cullen D. Genomewide analysis of polysaccharides degrading enzymes in 11 white- and brown-rot Polyporales provides insight into mechanisms of wood decay. Mycologia 2013; 105:1412-27. [PMID: 23935027 DOI: 10.3852/13-072] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To degrade the polysaccharides, wood-decay fungi secrete a variety of glycoside hydrolases (GHs) and carbohydrate esterases (CEs) classified into various sequence-based families of carbohydrate-active enzymes (CAZys) and their appended carbohydrate-binding modules (CBM). Oxidative enzymes, such as cellobiose dehydrogenase (CDH) and lytic polysaccharide monooxygenase (LPMO, formerly GH61), also have been implicated in cellulose degradation. To examine polysaccharide-degrading potential between white- and brown-rot fungi, we performed genomewide analysis of CAZys and these oxidative enzymes in 11 Polyporales, including recently sequenced monokaryotic strains of Bjerkandera adusta, Ganoderma sp. and Phlebia brevispora. Furthermore, we conducted comparative secretome analysis of seven Polyporales grown on wood culture. As a result, it was found that genes encoding cellulases belonging to families GH6, GH7, GH9 and carbohydrate-binding module family CBM1 are lacking in genomes of brown-rot polyporales. In addition, the presence of CDH and the expansion of LPMO were observed only in white-rot genomes. Indeed, GH6, GH7, CDH and LPMO peptides were identified only in white-rot polypores. Genes encoding aldose 1-epimerase (ALE), previously detected with CDH and cellulases in the culture filtrates, also were identified in white-rot genomes, suggesting a physiological connection between ALE, CDH, cellulase and possibly LPMO. For hemicellulose degradation, genes and peptides corresponding to GH74 xyloglucanase, GH10 endo-xylanase, GH79 β-glucuronidase, CE1 acetyl xylan esterase and CE15 glucuronoyl methylesterase were significantly increased in white-rot genomes compared to brown-rot genomes. Overall, relative to brown-rot Polyporales, white-rot Polyporales maintain greater enzymatic diversity supporting lignocellulose attack.
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Affiliation(s)
- Chiaki Hori
- Department of Biomaterials Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, l-l-l, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan, and Institute for Microbial and Biochemical Technology, Forest Products Laboratory, 1 Gifford Pinchot Drive, Madison, Wisconsin 53726
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C-terminal flanking peptide stabilized the catalytic domain of a recombinant Bacillus subtilis endo-β-1, 4-glucanase. Protein J 2013; 32:246-52. [PMID: 23543074 DOI: 10.1007/s10930-013-9483-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Three proteins, Egl330, Egl326 and Egl325, which covered the catalytic domain of a Bacillus subtilis endo-β-l, 4-glucanase were expressed in Escherichia coli and purified. Egl325 was a mutant of Egl330 with the peptide sequence Arg-Glu-Asn-Ile-Arg deleted in the C-terminus and Egl326 was another mutant of Egl330 with the peptide sequence Glu-Asn-Ile-Arg deleted in the C-terminus. These three proteins displayed same optimal reaction pH and temperature. However, the thermal stability and pH stability of Egl326 and Egl325 were diminished compared to Egl330. Results of ultra violet scanning, circular dichroism and Trp fluorescence spectrometry showed that the absence of the short peptide at the C-terminus of Egl330 resulted in the destabilization of the catalytic domain through affecting the folding of the protein.
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Prates ÉT, Stankovic I, Silveira RL, Liberato MV, Henrique-Silva F, Pereira N, Polikarpov I, Skaf MS. X-ray structure and molecular dynamics simulations of endoglucanase 3 from Trichoderma harzianum: structural organization and substrate recognition by endoglucanases that lack cellulose binding module. PLoS One 2013; 8:e59069. [PMID: 23516599 PMCID: PMC3597598 DOI: 10.1371/journal.pone.0059069] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 02/11/2013] [Indexed: 11/18/2022] Open
Abstract
Plant biomass holds a promise for the production of second-generation ethanol via enzymatic hydrolysis, but its utilization as a biofuel resource is currently limited to a large extent by the cost and low efficiency of the cellulolytic enzymes. Considerable efforts have been dedicated to elucidate the mechanisms of the enzymatic process. It is well known that most cellulases possess a catalytic core domain and a carbohydrate binding module (CBM), without which the enzymatic activity can be drastically reduced. However, Cel12A members of the glycosyl hydrolases family 12 (GHF12) do not bear a CBM and yet are able to hydrolyze amorphous cellulose quite efficiently. Here, we use X-ray crystallography and molecular dynamics simulations to unravel the molecular basis underlying the catalytic capability of endoglucanase 3 from Trichoderma harzianum (ThEG3), a member of the GHF12 enzymes that lacks a CBM. A comparative analysis with the Cellulomonas fimi CBM identifies important residues mediating interactions of EG3s with amorphous regions of the cellulose. For instance, three aromatic residues constitute a harboring wall of hydrophobic contacts with the substrate in both ThEG3 and CfCBM structures. Moreover, residues at the entrance of the active site cleft of ThEG3 are identified, which might hydrogen bond to the substrate. We advocate that the ThEG3 residues Asn152 and Glu201 interact with the substrate similarly to the corresponding CfCBM residues Asn81 and Arg75. Altogether, these results show that CBM motifs are incorporated within the ThEG3 catalytic domain and suggest that the enzymatic efficiency is associated with the length and position of the substrate chain, being higher when the substrate interact with the aromatic residues at the entrance of the cleft and the catalytic triad. Our results provide guidelines for rational protein engineering aiming to improve interactions of GHF12 enzymes with cellulosic substrates.
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Affiliation(s)
- Érica T. Prates
- Institute of Chemistry, State University of Campinas–UNICAMP. Cx.P. 6154, Campinas, São Paulo, Brazil
| | - Ivana Stankovic
- Institute of Chemistry, State University of Campinas–UNICAMP. Cx.P. 6154, Campinas, São Paulo, Brazil
| | - Rodrigo L. Silveira
- Institute of Chemistry, State University of Campinas–UNICAMP. Cx.P. 6154, Campinas, São Paulo, Brazil
| | - Marcelo V. Liberato
- Institute of Physics of São Carlos, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Flávio Henrique-Silva
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Nei Pereira
- Centro de Tecnologia, Escola de Química, Laboratório de Desenvolvimento de Bioprocessos (LaDeBio), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Igor Polikarpov
- Institute of Physics of São Carlos, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Munir S. Skaf
- Institute of Chemistry, State University of Campinas–UNICAMP. Cx.P. 6154, Campinas, São Paulo, Brazil
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Thompson AJ, Heu T, Shaghasi T, Benyamino R, Jones A, Friis EP, Wilson KS, Davies GJ. Structure of the catalytic core module of theChaetomium thermophilumfamily GH6 cellobiohydrolase Cel6A. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:875-82. [DOI: 10.1107/s0907444912016496] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 04/16/2012] [Indexed: 11/11/2022]
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Rader AJ, Yennamalli RM, Harter AK, Sen TZ. A rigid network of long-range contacts increases thermostability in a mutant endoglucanase. J Biomol Struct Dyn 2012; 30:628-37. [PMID: 22731517 DOI: 10.1080/07391102.2012.689696] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Thermodynamic stability of a protein at elevated temperatures is a key factor for thermostable enzymes to catalyze their specific reactions. Yet our understanding of biological determinants of thermostability is far from complete. Many different atomistic factors have been suggested as possible means for such proteins to preserve their activity at high temperatures. Among these factors are specific local interatomic interactions or enrichment of specific amino acid types. The case of glycosyl hydrolase family endoglucanase of Trichoderma reesei defies current hypotheses for thermostability because a single mutation far from the active site (A35 V) converts this mesostable protein into a thermostable protein without significant change in the protein structure. This substantial change in enzymatic activity cannot be explained on the basis of local intramolecular interactions alone. Here we present a more global view of the induced thermostability and show that the A35 V mutation affects the underlying structural rigidity of the whole protein via a number of long-range, non-local interactions. Our analysis of this structure reveals a precisely tuned, rigid network of atomic interactions. This cooperative, allosteric effect promotes the transformation of this mesostable protein into a thermostable one.
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Affiliation(s)
- A J Rader
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA.
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Bayram Akcapinar G, Gul O, Sezerman UO. From in silico to in vitro: Modelling and production of Trichoderma reesei endoglucanase 1 and its mutant in Pichia pastoris. J Biotechnol 2012; 159:61-8. [DOI: 10.1016/j.jbiotec.2012.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 01/02/2012] [Accepted: 01/04/2012] [Indexed: 10/28/2022]
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Yoshizawa T, Shimizu T, Hirano H, Sato M, Hashimoto H. Structural basis for inhibition of xyloglucan-specific endo-β-1,4-glucanase (XEG) by XEG-protein inhibitor. J Biol Chem 2012; 287:18710-6. [PMID: 22496365 DOI: 10.1074/jbc.m112.350520] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microorganisms such as plant pathogens secrete glycoside hydrolases (GHs) to digest the polysaccharide chains of plant cell walls. The degradation of cell walls by these enzymes is a crucial step for nutrition and invasion. To protect the cell wall from these enzymes, plants secrete glycoside hydrolase inhibitor proteins (GHIPs). Xyloglucan-specific endo-β-1,4-glucanase (XEG), a member of GH family 12 (GH12), could be a great threat to many plants because xyloglucan is a major component of the cell wall in most plants. Understanding the inhibition mechanism of XEG by GHIP is therefore of great importance in the field of plant defense, but to date the mechanism and specificity of GHIPs remain unclear. We have determined the crystal structure of XEG in complex with extracellular dermal glycoprotein (EDGP), a carrot GHIP that inhibits XEG. The structure reveals that the conserved arginines of EDGP intrude into the active site of XEG and interact with the catalytic glutamates of the enzyme. We have also determined the crystal structure of the XEG-xyloglucan complex. These structures show that EDGP closely mimics the XEG-xyloglucan interaction. Although EDGP shares structural similarity to a wheat GHIP (Triticum aestivum xylanase inhibitor-IA (TAXI-IA)) that inhibits GH11 family xylanases, the arrangement of GH and GHIP in the XEG-EDGP complex is distinct from that in the xylanase-TAXI-IA complex. Our findings imply that plants have evolved structures of GHIPs to inhibit different GH family members that attack their cell walls.
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Affiliation(s)
- Takuya Yoshizawa
- Graduate School of Nanobioscience, Yokohama City University, Tsurumi-ku, Yokohama, Kanagawa, Japan
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Park YB, Cosgrove DJ. A revised architecture of primary cell walls based on biomechanical changes induced by substrate-specific endoglucanases. PLANT PHYSIOLOGY 2012; 158:1933-43. [PMID: 22362871 PMCID: PMC3320196 DOI: 10.1104/pp.111.192880] [Citation(s) in RCA: 241] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 02/23/2012] [Indexed: 05/17/2023]
Abstract
Xyloglucan is widely believed to function as a tether between cellulose microfibrils in the primary cell wall, limiting cell enlargement by restricting the ability of microfibrils to separate laterally. To test the biomechanical predictions of this "tethered network" model, we assessed the ability of cucumber (Cucumis sativus) hypocotyl walls to undergo creep (long-term, irreversible extension) in response to three family-12 endo-β-1,4-glucanases that can specifically hydrolyze xyloglucan, cellulose, or both. Xyloglucan-specific endoglucanase (XEG from Aspergillus aculeatus) failed to induce cell wall creep, whereas an endoglucanase that hydrolyzes both xyloglucan and cellulose (Cel12A from Hypocrea jecorina) induced a high creep rate. A cellulose-specific endoglucanase (CEG from Aspergillus niger) did not cause cell wall creep, either by itself or in combination with XEG. Tests with additional enzymes, including a family-5 endoglucanase, confirmed the conclusion that to cause creep, endoglucanases must cut both xyloglucan and cellulose. Similar results were obtained with measurements of elastic and plastic compliance. Both XEG and Cel12A hydrolyzed xyloglucan in intact walls, but Cel12A could hydrolyze a minor xyloglucan compartment recalcitrant to XEG digestion. Xyloglucan involvement in these enzyme responses was confirmed by experiments with Arabidopsis (Arabidopsis thaliana) hypocotyls, where Cel12A induced creep in wild-type but not in xyloglucan-deficient (xxt1/xxt2) walls. Our results are incompatible with the common depiction of xyloglucan as a load-bearing tether spanning the 20- to 40-nm spacing between cellulose microfibrils, but they do implicate a minor xyloglucan component in wall mechanics. The structurally important xyloglucan may be located in limited regions of tight contact between microfibrils.
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Kim HW, Kataoka M, Ishikawa K. Atomic resolution of the crystal structure of the hyperthermophilic family 12 endocellulase and stabilizing role of the DxDxDG calcium-binding motif in Pyrococcus furiosus. FEBS Lett 2012; 586:1009-13. [PMID: 22569255 DOI: 10.1016/j.febslet.2012.02.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/30/2012] [Accepted: 02/20/2012] [Indexed: 10/28/2022]
Abstract
Hyperthermophilic glycoside hydrolase family 12 endocellulase (EGPf) from the archaeon Pyrococcus furiosus catalyzes the hydrolytic cleavage of β-1,4-glucosidic linkage in β-glucan cellulose. A truncated EGPf (EGPfΔN30) mutant lacking the proline and hydroxyl-residue rich region at the N terminus was constructed, and its crystal structure was resolved at an atomic resolution of 1.07 Å. Our results indicate that the structure of EGPf, which consists of a β-jelly roll, exhibits structural similarity with the endocellulase of Thermotoga maritima. Additionally, we further determined that the thermostability of EGPf is maintained in part by the binding of Ca²⁺ in a DxDxDG Ca²⁺-binding motif, atypical of most archaeal proteins.
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Affiliation(s)
- Han-Woo Kim
- National Institute of Advanced Industrial Science and Technology, Biomass Technology Research Center, 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
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Expression of novel β-glucanase Cel12A from Stachybotrys atra in bacterial and fungal hosts. Fungal Biol 2012; 116:443-51. [PMID: 22385626 DOI: 10.1016/j.funbio.2012.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 01/12/2012] [Accepted: 01/17/2012] [Indexed: 11/23/2022]
Abstract
β-glucanase Cel12A from Stachybotrys atra has been cloned and expressed in Aspergillus niger. The purified enzyme showed high activity of β-1,3-1,4-mixed glucans, was also active on carboxymethylcellulose (CMC), while it did not hydrolyze crystalline cellulose or β-1,3 glucans as laminarin. Cel12A showed a marked substrate preference for β-1,3-1,4 glucans, showing maximum activity on barley β-glucans (27.69 U mg(-1)) while the activity on CMC was much lower (0.51 U mg(-1)). Analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF), and zymography showed the recombinant enzyme has apparent molecular weight of 24 kDa and a pI of 8.2. Optimal temperature and pH for enzyme activity were 50°C and pH 6.5. Thin layer chromatography analysis showed that major hydrolysis products from barley β-glucan and lichean were 3-O-β-cellotriosyl-D-glucose and 3-O-β-cellobiosyl-D-glucose, while glucose and cellobiose were released in smaller amounts. The amino acid sequence deduced from cel12A revealed that it is a single domain enzyme belonging to the GH12 family, a family that contains several endoglucanases with substrate preference for β-1,3-1,4 glucans. We believe that S. atra Cel12A should be considered as a lichenase-like or nontypical endoglucanase.
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Damásio ARL, Ribeiro LFC, Ribeiro LF, Furtado GP, Segato F, Almeida FBR, Crivellari AC, Buckeridge MS, Souza TACB, Murakami MT, Ward RJ, Prade RA, Polizeli MLTM. Functional characterization and oligomerization of a recombinant xyloglucan-specific endo-β-1,4-glucanase (GH12) from Aspergillus niveus. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:461-7. [PMID: 22230786 DOI: 10.1016/j.bbapap.2011.12.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 12/20/2011] [Accepted: 12/21/2011] [Indexed: 11/16/2022]
Abstract
Xyloglucan is a major structural polysaccharide of the primary (growing) cell wall of higher plants. It consists of a cellulosic backbone (beta-1,4-linked glucosyl residues) that is frequently substituted with side chains. This report describes Aspergillus nidulans strain A773 recombinant secretion of a dimeric xyloglucan-specific endo-β-1,4-glucanohydrolase (XegA) cloned from Aspergillus niveus. The ORF of the A. niveus xegA gene is comprised of 714 nucleotides, and encodes a 238 amino acid protein with a calculated molecular weight of 23.5kDa and isoelectric point of 4.38. The optimal pH and temperature were 6.0 and 60°C, respectively. XegA generated a xyloglucan-oligosaccharides (XGOs) pattern similar to that observed for cellulases from family GH12, i.e., demonstrating that its mode of action includes hydrolysis of the glycosidic linkages between glucosyl residues that are not branched with xylose. In contrast to commercial lichenase, mixed linkage beta-glucan (lichenan) was not digested by XegA, indicating that the enzyme did not cleave glucan β-1,3 or β-1,6 bonds. The far-UV CD spectrum of the purified enzyme indicated a protein rich in β-sheet structures as expected for GH12 xyloglucanases. Thermal unfolding studies displayed two transitions with mid-point temperatures of 51.3°C and 81.3°C respectively, and dynamic light scattering studies indicated that the first transition involves a change in oligomeric state from a dimeric to a monomeric form. Since the enzyme is a predominantly a monomer at 60°C, the enzymatic assays demonstrated that XegA is more active in its monomeric state.
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Affiliation(s)
- André R L Damásio
- Departamento de Bioquímica e Imunologia, Universidade de São Paulo, Ribeirão Preto, Brazil
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Processive and nonprocessive cellulases for biofuel production—lessons from bacterial genomes and structural analysis. Appl Microbiol Biotechnol 2011; 93:497-502. [DOI: 10.1007/s00253-011-3701-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 10/18/2011] [Accepted: 11/01/2011] [Indexed: 01/26/2023]
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50
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Li DC, Li AN, Papageorgiou AC. Cellulases from thermophilic fungi: recent insights and biotechnological potential. Enzyme Res 2011; 2011:308730. [PMID: 22145076 PMCID: PMC3226318 DOI: 10.4061/2011/308730] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/05/2011] [Accepted: 09/07/2011] [Indexed: 11/24/2022] Open
Abstract
Thermophilic fungal cellulases are promising enzymes in protein engineering efforts aimed at optimizing industrial processes, such as biomass degradation and biofuel production. The cloning and expression in recent years of new cellulase genes from thermophilic fungi have led to a better understanding of cellulose degradation in these species. Moreover, crystal structures of thermophilic fungal cellulases are now available, providing insights into their function and stability. The present paper is focused on recent progress in cloning, expression, regulation, and structure of thermophilic fungal cellulases and the current research efforts to improve their properties for better use in biotechnological applications.
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Affiliation(s)
- Duo-Chuan Li
- Department of Environmental Biology, Shandong Agricultural University, Taian, Shandong 271018, China
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