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Dou Z, He J, Han C, Wu X, Wan L, Yang J, Zheng Y, Gong B, Wang L. qProtein: Exploring Physical Features of Protein Thermostability Based on Structural Proteomics. J Chem Inf Model 2024. [PMID: 39375829 DOI: 10.1021/acs.jcim.4c01303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
Thermostability, which is essential for the functional performance of enzymes, is largely determined by intramolecular physical interactions. Although many tools have been developed, existing computational methods have struggled to find the universal principles of protein thermostability. Recent advancements in structural proteomics have been driven by the introduction of deep neural networks such as AlphaFold2 and ESMFold. These innovations have enabled the characterization of protein structures with unprecedented speed and accuracy. Here, we introduce qProtein, a Python-implemented workflow designed for the quantitative analysis of physical interactions on the scale of structural proteomics. This platform accepts protein sequences as input and produces four structural features, including hydrophobic clusters, hydrogen bonds, electrostatic interactions, and disulfide bonds. To demonstrate the use of qProtein, we investigate the structural features related to protein thermostability in six glycoside hydrolase (GH) families, comprising a total of 3,811 protein structures. Our results indicate that in five enzyme families (GH11, GH12, GH5_2, GH10, and GH48), the thermophilic enzymes have a larger average area of hydrophobic clusters compared to the nonthermophilic enzymes within each family. Furthermore, our analysis of the local-structure regions reveals that the hydrophobic clusters are predominantly distributed in the distal regions of the GH11 enzymes. In addition, the average hydrophobic cluster area of the thermophilic enzymes is significantly higher than that of the nonthermophilic enzymes in the distal regions of the GH11 enzymes. Therefore, qProtein is a well-suited platform for analyzing the structural features of thermal stability at the level of structural proteomics. We provide the source code for qProtein at https://github.com/bj600800/qProtein, and the web server is available at http://qProtein.sdu.edu.cn:8888.
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Affiliation(s)
- Zhixin Dou
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
| | - Jiaxin He
- School of Computer Science and Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
| | - Chao Han
- Shandong Key Laboratory of Agricultural Microbiology, Shandong Agricultural University, Tai'an 271018, China
| | - Xiuyun Wu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
| | - Lin Wan
- School of Software, Shandong University, Shunhua Road, Jinan 250101, P.R. China
| | - Jian Yang
- School of Computer Science and Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
| | - Yanwei Zheng
- School of Computer Science and Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
| | - Bin Gong
- School of Software, Shandong University, Shunhua Road, Jinan 250101, P.R. China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P.R. China
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Kataoka M, Kim HW, Ishikawa K. Recognition mechanism of endocellulase for β-glucan containing β(1 → 3),(1 → 4) mixed-linkages. Carbohydr Res 2022; 522:108682. [DOI: 10.1016/j.carres.2022.108682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/02/2022] [Accepted: 09/18/2022] [Indexed: 11/02/2022]
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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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Zhou HY, Yi XN, Chen Q, Zhou JB, Li SF, Cai X, Chen DS, Cheng XP, Li M, Wang HY, Chen KQ, Liu ZQ, Zheng YG. Improvement of catalytic performance of endoglucanase CgEndo from Colletotrichum graminicola by site-directed mutagenesis. Enzyme Microb Technol 2021; 154:109963. [PMID: 34971884 DOI: 10.1016/j.enzmictec.2021.109963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/22/2021] [Accepted: 12/06/2021] [Indexed: 11/03/2022]
Abstract
In order to improve the catalytic efficiency of cellulase for more effective utilization of lignocellulose, a novel endoglucanase (CgEndo) from Colletotrichum graminicola was expressed by Pichia pastoris X33 and modified by site-directed mutagenesis. Two mutants, Y63S and N20D/S113T, with 62.31% and 57.14% increased enzyme activities were obtained, respectively. On this basis, their biochemical properties, kinetic parameters, structural information as well as the application in biomass degradation were investigated and compared with the wild-type CgEngo. The results indicated that the mutation Y63S and N20D/S113T resulted in an improvement of proximity between enzyme and substrate through conformational changes of the catalytic region, which might contribute to the higher enzyme activities and catalysis efficiency (Kcat/Km) of Y63S and N20D/S113T. These findings laid important foundation for the further engineering of this endoglucanase and practical application in efficient degradation of cellulosic biomass in nature.
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Affiliation(s)
- Hai-Yan Zhou
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Xiao-Nan Yi
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Qi Chen
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Jian-Bao Zhou
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Shu-Fang Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Xue Cai
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - De-Shui Chen
- Zhejiang Huakang Pharmaceutical Co., LTD., 18 Huagong Road, Huabu Town, Kaihua 324302, People's Republic of China
| | - Xin-Ping Cheng
- Zhejiang Huakang Pharmaceutical Co., LTD., 18 Huagong Road, Huabu Town, Kaihua 324302, People's Republic of China
| | - Mian Li
- Zhejiang Huakang Pharmaceutical Co., LTD., 18 Huagong Road, Huabu Town, Kaihua 324302, People's Republic of China
| | - Hong-Yan Wang
- Zhejiang Huakang Pharmaceutical Co., LTD., 18 Huagong Road, Huabu Town, Kaihua 324302, People's Republic of China
| | - Kai-Qian Chen
- Zhejiang Huakang Pharmaceutical Co., LTD., 18 Huagong Road, Huabu Town, Kaihua 324302, People's Republic of China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
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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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Li L, Liu C, Qu M, Zhang W, Pan K, OuYang K, Song X, Zhao X. Characteristics of a recombinant Lentinula edodes endoglucanase and its potential for application in silage of rape straw. Int J Biol Macromol 2019; 139:49-56. [PMID: 31374269 DOI: 10.1016/j.ijbiomac.2019.07.199] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/29/2019] [Accepted: 07/29/2019] [Indexed: 12/12/2022]
Abstract
An experiment was conducted to determine the characteristics of recombinant endoglucanase and its effects on rape straw silage. The endoglucanase from Lentinula edodes (LeCel12A) was produced in Pichia pastoris and shown maximum activity at 40 °C and pH 3.0. The LeCel12A exhibited preferential hydrolysis of carboxymethylcellulose. The activity of LeCel12A could be enhanced by MnCl2 in dose-dependent manners. Trp22 was a key amino acid affecting LeCel12A activity. The LeCel12A enhanced the hydrolysis of rape straw, rice straw, wheat straw, and corn straw. Supplemental LeCel12A increased lactic acid concentration and reduced lignocellulosic content of the rape straw silage. Though an increase in the saccharification efficiency of LeCel12A-treated rape straw silage was observed when the fibrolytic enzyme loading of hydrolysis system was enough, supplemental LeCel12A did not dramatically enhance the saccharification of rape straw silage in the current study. This study demonstrates that LeCel12A may be useful for improving the utilization of rape straw silage as an additive, but its supplemental dose, cost benefit, and consequent application possibility in biofuel production require careful consideration and further investigation.
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Affiliation(s)
- Lizhi Li
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China; College of Life science and Resources and Environment, Yichun University, Yichun, 336000, China
| | - Chanjuan Liu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Mingren Qu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Wenjing Zhang
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Ke Pan
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Kehui OuYang
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xiaozhen Song
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xianghui Zhao
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China.
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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: 11] [Impact Index Per Article: 2.2] [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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9
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Improving the specific activity and thermo-stability of alkaline pectate lyase from Bacillus subtilis 168 for bioscouring. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2017.11.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Druzhinina IS, Kubicek CP. Genetic engineering of Trichoderma reesei cellulases and their production. Microb Biotechnol 2017; 10:1485-1499. [PMID: 28557371 PMCID: PMC5658622 DOI: 10.1111/1751-7915.12726] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 11/26/2022] Open
Abstract
Lignocellulosic biomass, which mainly consists of cellulose, hemicellulose and lignin, is the most abundant renewable source for production of biofuel and biorefinery products. The industrial use of plant biomass involves mechanical milling or chipping, followed by chemical or physicochemical pretreatment steps to make the material more susceptible to enzymatic hydrolysis. Thereby the cost of enzyme production still presents the major bottleneck, mostly because some of the produced enzymes have low catalytic activity under industrial conditions and/or because the rate of hydrolysis of some enzymes in the secreted enzyme mixture is limiting. Almost all of the lignocellulolytic enzyme cocktails needed for the hydrolysis step are produced by fermentation of the ascomycete Trichoderma reesei (Hypocreales). For this reason, the structure and mechanism of the enzymes involved, the regulation of their expression and the pathways of their formation and secretion have been investigated in T. reesei in considerable details. Several of the findings thereby obtained have been used to improve the formation of the T. reesei cellulases and their properties. In this article, we will review the achievements that have already been made and also show promising fields for further progress.
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Affiliation(s)
- Irina S. Druzhinina
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
| | - Christian P. Kubicek
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
- Present address:
Steinschötelgasse 7Wien1100Austria
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11
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Chwastyk M, Vera AM, Galera-Prat A, Gunnoo M, Thompson D, Carrión-Vázquez M, Cieplak M. Non-local effects of point mutations on the stability of a protein module. J Chem Phys 2017; 147:105101. [DOI: 10.1063/1.4999703] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mateusz Chwastyk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, PL-02668 Warsaw, Poland
| | - Andrés M. Vera
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, (CSIC), Ave. Doctor Arce, 37, 28002 Madrid, Spain
| | - Albert Galera-Prat
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, (CSIC), Ave. Doctor Arce, 37, 28002 Madrid, Spain
| | - Melissabye Gunnoo
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Mariano Carrión-Vázquez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, (CSIC), Ave. Doctor Arce, 37, 28002 Madrid, Spain
| | - Marek Cieplak
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, PL-02668 Warsaw, Poland
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12
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Goedegebuur F, Dankmeyer L, Gualfetti P, Karkehabadi S, Hansson H, Jana S, Huynh V, Kelemen BR, Kruithof P, Larenas EA, Teunissen PJM, Ståhlberg J, Payne CM, Mitchinson C, Sandgren M. Improving the thermal stability of cellobiohydrolase Cel7A from Hypocrea jecorina by directed evolution. J Biol Chem 2017; 292:17418-17430. [PMID: 28860192 DOI: 10.1074/jbc.m117.803270] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/24/2017] [Indexed: 11/06/2022] Open
Abstract
Secreted mixtures of Hypocrea jecorina cellulases are able to efficiently degrade cellulosic biomass to fermentable sugars at large, commercially relevant scales. H. jecorina Cel7A, cellobiohydrolase I, from glycoside hydrolase family 7, is the workhorse enzyme of the process. However, the thermal stability of Cel7A limits its use to processes where temperatures are no higher than 50 °C. Enhanced thermal stability is desirable to enable the use of higher processing temperatures and to improve the economic feasibility of industrial biomass conversion. Here, we enhanced the thermal stability of Cel7A through directed evolution. Sites with increased thermal stability properties were combined, and a Cel7A variant (FCA398) was obtained, which exhibited a 10.4 °C increase in Tm and a 44-fold greater half-life compared with the wild-type enzyme. This Cel7A variant contains 18 mutated sites and is active under application conditions up to at least 75 °C. The X-ray crystal structure of the catalytic domain was determined at 2.1 Å resolution and showed that the effects of the mutations are local and do not introduce major backbone conformational changes. Molecular dynamics simulations revealed that the catalytic domain of wild-type Cel7A and the FCA398 variant exhibit similar behavior at 300 K, whereas at elevated temperature (475 and 525 K), the FCA398 variant fluctuates less and maintains more native contacts over time. Combining the structural and dynamic investigations, rationales were developed for the stabilizing effect at many of the mutated sites.
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Affiliation(s)
- Frits Goedegebuur
- From DuPont Industrial Biosciences, Archimedesweg 30, Leiden 2333CN, The Netherlands,
| | - Lydia Dankmeyer
- From DuPont Industrial Biosciences, Archimedesweg 30, Leiden 2333CN, The Netherlands
| | | | - Saeid Karkehabadi
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, Uppsala SE-75007, Sweden, and
| | - Henrik Hansson
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, Uppsala SE-75007, Sweden, and
| | - Suvamay Jana
- the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506
| | - Vicky Huynh
- DuPont Industrial Biosciences, Palo Alto, California 94304
| | | | - Paulien Kruithof
- From DuPont Industrial Biosciences, Archimedesweg 30, Leiden 2333CN, The Netherlands
| | | | | | - Jerry Ståhlberg
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, Uppsala SE-75007, Sweden, and
| | - Christina M Payne
- the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506
| | | | - Mats Sandgren
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, Uppsala SE-75007, Sweden, and
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13
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Geertz-Hansen HM, Kiemer L, Nielsen M, Stanchev K, Blom N, Brunak S, Petersen TN. Protein features as determinants of wild-type glycoside hydrolase thermostability. Proteins 2017; 85:2036-2044. [DOI: 10.1002/prot.25357] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/26/2017] [Accepted: 07/21/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Henrik Marcus Geertz-Hansen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark; DK-2800 Lyngby Denmark
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
- Novozymes A/S; DK-2880 Bagsvaerd Denmark
| | | | - Morten Nielsen
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
- Instituto de Investigaciones Biotecnologicas, Universidad Nacional de San Martin, San Martin, B 1650 HMP; Buenos Aires Argentina
| | - Kiril Stanchev
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
| | - Nikolaj Blom
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark; DK-2800 Lyngby Denmark
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
| | - Søren Brunak
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
- Faculty of Health and Medical Sciences; Novo Nordisk Foundation Center for Protein Research, University of Copenhagen; DK-2200 Copenhagen N Denmark
| | - Thomas Nordahl Petersen
- Department of Bio and Health Informatics; Technical University of Denmark, Kemitorvet; DK-2800 Lyngby Denmark
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14
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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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15
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Fraga KJ, Joo H, Tsai J. An amino acid code to define a protein's tertiary packing surface. Proteins 2015; 84:201-16. [PMID: 26575337 DOI: 10.1002/prot.24966] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 09/24/2015] [Accepted: 11/09/2015] [Indexed: 01/28/2023]
Abstract
One difficult aspect of the protein-folding problem is characterizing the nonspecific interactions that define packing in protein tertiary structure. To better understand tertiary structure, this work extends the knob-socket model by classifying the interactions of a single knob residue packed into a set of contiguous sockets, or a pocket made up of 4 or more residues. The knob-socket construct allows for a symbolic two-dimensional mapping of pockets. The two-dimensional mapping of pockets provides a simple method to investigate the variety of pocket shapes to understand the geometry of protein tertiary surfaces. The diversity of pocket geometries can be organized into groups of pockets that share a common core, which suggests that some interactions in pockets are ancillary to packing. Further analysis of pocket geometries displays a preferred configuration that is right-handed in α-helices and left-handed in β-sheets. The amino acid composition of pockets illustrates the importance of nonpolar amino acids in packing as well as position specificity. As expected, all pocket shapes prefer to pack with hydrophobic knobs; however, knobs are not selective for the pockets they pack. Investigating side-chain rotamer preferences for certain pocket shapes uncovers no strong correlations. These findings allow a simple vocabulary based on knobs and sockets to describe protein tertiary packing that supports improved analysis, design, and prediction of protein structure.
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Affiliation(s)
- Keith J Fraga
- Department of Chemistry, University of the Pacific, Stockton, California, 95211
| | - Hyun Joo
- Department of Chemistry, University of the Pacific, Stockton, California, 95211
| | - Jerry Tsai
- Department of Chemistry, University of the Pacific, Stockton, California, 95211
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16
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Pierre B, Labonte JW, Xiong T, Aoraha E, Williams A, Shah V, Chau E, Helal KY, Gray JJ, Kim JR. Molecular Determinants for Protein Stabilization by Insertional Fusion to a Thermophilic Host Protein. Chembiochem 2015; 16:2392-402. [DOI: 10.1002/cbic.201500310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Brennal Pierre
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Jason W. Labonte
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Tina Xiong
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Edwin Aoraha
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Asher Williams
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Vandan Shah
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Edward Chau
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Kazi Yasin Helal
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Jeffrey J. Gray
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
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17
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Abstract
SUMMARY Biomass is constructed of dense recalcitrant polymeric materials: proteins, lignin, and holocellulose, a fraction constituting fibrous cellulose wrapped in hemicellulose-pectin. Bacteria and fungi are abundant in soil and forest floors, actively recycling biomass mainly by extracting sugars from holocellulose degradation. Here we review the genome-wide contents of seven Aspergillus species and unravel hundreds of gene models encoding holocellulose-degrading enzymes. Numerous apparent gene duplications followed functional evolution, grouping similar genes into smaller coherent functional families according to specialized structural features, domain organization, biochemical activity, and genus genome distribution. Aspergilli contain about 37 cellulase gene models, clustered in two mechanistic categories: 27 hydrolyze and 10 oxidize glycosidic bonds. Within the oxidative enzymes, we found two cellobiose dehydrogenases that produce oxygen radicals utilized by eight lytic polysaccharide monooxygenases that oxidize glycosidic linkages, breaking crystalline cellulose chains and making them accessible to hydrolytic enzymes. Among the hydrolases, six cellobiohydrolases with a tunnel-like structural fold embrace single crystalline cellulose chains and cooperate at nonreducing or reducing end termini, splitting off cellobiose. Five endoglucanases group into four structural families and interact randomly and internally with cellulose through an open cleft catalytic domain, and finally, seven extracellular β-glucosidases cleave cellobiose and related oligomers into glucose. Aspergilli contain, on average, 30 hemicellulase and 7 accessory gene models, distributed among 9 distinct functional categories: the backbone-attacking enzymes xylanase, mannosidase, arabinase, and xyloglucanase, the short-side-chain-removing enzymes xylan α-1,2-glucuronidase, arabinofuranosidase, and xylosidase, and the accessory enzymes acetyl xylan and feruloyl esterases.
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18
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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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19
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20
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Lee CW, Wang HJ, Hwang JK, Tseng CP. Protein thermal stability enhancement by designing salt bridges: a combined computational and experimental study. PLoS One 2014; 9:e112751. [PMID: 25393107 PMCID: PMC4231051 DOI: 10.1371/journal.pone.0112751] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 10/18/2014] [Indexed: 11/21/2022] Open
Abstract
Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, a novel method for salt-bridge design was proposed based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures. These salt bridges were first categorized based on pairing residues, secondary structure locations, and Cα–Cα distances. Pairing preferences generalized from statistical analysis were used to construct a salt-bridge pair index and utilized in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number, relative solvent accessibility, and conservation prescreening to determine the residues appropriate for the thermal adaptive design of salt bridges. According to our method, eight putative salt-bridges were designed on a mesophilic β-glucosidase and 24 variants were constructed to verify the predictions. Six putative salt-bridges leaded to the increase of the enzyme thermal stability. A significant increase in melting temperature of 8.8, 4.8, 3.7, 1.3, 1.2, and 0.7°C of the putative salt-bridges N437K–D49, E96R–D28, E96K–D28, S440K–E70, T231K–D388, and Q277E–D282 was detected, respectively. Reversing the polarity of T231K–D388 to T231D–D388K resulted in a further increase in melting temperatures by 3.6°C, which may be caused by the transformation of an intra-subunit electrostatic interaction into an inter-subunit one depending on the local environment. The combination of the thermostable variants (N437K, E96R, T231D and D388K) generated a melting temperature increase of 15.7°C. Thus, this study demonstrated a novel method for the thermal adaptive design of salt bridges through inference of suitable positions and substitutions.
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Affiliation(s)
- Chi-Wen Lee
- Institute of Bioinformatics and Systems Biology, College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Hsiu-Jung Wang
- Department of Biological Science and Technology, College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Jenn-Kang Hwang
- Institute of Bioinformatics and Systems Biology, College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
- * E-mail: (JKH); (CPT)
| | - Ching-Ping Tseng
- Department of Biological Science and Technology, College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
- * E-mail: (JKH); (CPT)
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21
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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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22
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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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23
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SAXS Studies of the Endoglucanase Cel12A from Gloeophyllum trabeum Show Its Monomeric Structure and Reveal the Influence of Temperature on the Structural Stability of the Enzyme. MATERIALS 2014; 7:5202-5211. [PMID: 28788125 PMCID: PMC5455812 DOI: 10.3390/ma7075202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/10/2014] [Accepted: 06/24/2014] [Indexed: 11/21/2022]
Abstract
Endoglucanases are key enzymes applied to the conversion of biomass aiming for second generation biofuel production. In the present study we obtained the small angle X-ray scattering (SAXS) structure of the G. trabeumendo-1,4-β-glucanase Cel12A and investigated the influence of an important parameter, temperature, on both secondary and tertiary structure of the enzyme and its activity. The CD analysis for GtCel12A revealed that changes in the CD spectra starts at 55 °C and the Tm calculated from the experimental CD sigmoid curve using the Boltzmann function was 60.2 ± 0.6 °C. SAXS data showed that GtCel12A forms monomers in solution and has an elongated form with a maximum diameter of 60 ± 5 Å and a gyration radius of 19.4 ± 0.1 Å as calculated from the distance distribution function. Kratky analysis revealed that 60 °C is the critical temperature above which we observed clear indications of denaturation. Our results showed the influence of temperature on the stability and activity of enzymes and revealed novel structural features of GtCel12A.
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24
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Lehmann C, Bocola M, Streit WR, Martinez R, Schwaneberg U. Ionic liquid and deep eutectic solvent-activated CelA2 variants generated by directed evolution. Appl Microbiol Biotechnol 2014; 98:5775-85. [DOI: 10.1007/s00253-014-5771-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 10/25/2022]
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25
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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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26
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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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Yennamalli RM, Rader AJ, Kenny AJ, Wolt JD, Sen TZ. Endoglucanases: insights into thermostability for biofuel applications. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:136. [PMID: 24070146 PMCID: PMC3856469 DOI: 10.1186/1754-6834-6-136] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/24/2013] [Indexed: 05/03/2023]
Abstract
Obtaining bioethanol from cellulosic biomass involves numerous steps, among which the enzymatic conversion of the polymer to individual sugar units has been a main focus of the biotechnology industry. Among the cellulases that break down the polymeric cellulose are endoglucanases that act synergistically for subsequent hydrolytic reactions. The endoglucanases that have garnered relatively more attention are those that can withstand high temperatures, i.e., are thermostable. Although our understanding of thermostability in endoglucanases is incomplete, some molecular features that are responsible for increased thermostability have been recently identified. This review focuses on the investigations of endoglucanases and their implications for biofuel applications.
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Affiliation(s)
- Ragothaman M Yennamalli
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames 50011, IA, USA
- Present Address: Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Andrew J Rader
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis 46202, IN, USA
- Present Address: State Farm Insurance, Indianapolis 46240, IN, USA
| | - Adam J Kenny
- Biosafety Institute for Genetically Modified Agricultural Products and Department of Agronomy, Iowa State University, Ames 50011, IA, USA
- Present Address: Brownells, Inc, Montezuma, IA 50171, USA
| | - Jeffrey D Wolt
- Biosafety Institute for Genetically Modified Agricultural Products and Department of Agronomy, Iowa State University, Ames 50011, IA, USA
| | - Taner Z Sen
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames 50011, IA, USA
- Bioinformatics and Computational Biology Program, Iowa State University, Ames 50011, IA, USA
- 1025 Crop Genome Informatics Lab, Iowa State University, Ames 50011, IA, USA
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28
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Singh RK, Tiwari MK, Singh R, Lee JK. From protein engineering to immobilization: promising strategies for the upgrade of industrial enzymes. Int J Mol Sci 2013; 14:1232-77. [PMID: 23306150 PMCID: PMC3565319 DOI: 10.3390/ijms14011232] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 11/14/2012] [Accepted: 12/24/2012] [Indexed: 11/16/2022] Open
Abstract
Enzymes found in nature have been exploited in industry due to their inherent catalytic properties in complex chemical processes under mild experimental and environmental conditions. The desired industrial goal is often difficult to achieve using the native form of the enzyme. Recent developments in protein engineering have revolutionized the development of commercially available enzymes into better industrial catalysts. Protein engineering aims at modifying the sequence of a protein, and hence its structure, to create enzymes with improved functional properties such as stability, specific activity, inhibition by reaction products, and selectivity towards non-natural substrates. Soluble enzymes are often immobilized onto solid insoluble supports to be reused in continuous processes and to facilitate the economical recovery of the enzyme after the reaction without any significant loss to its biochemical properties. Immobilization confers considerable stability towards temperature variations and organic solvents. Multipoint and multisubunit covalent attachments of enzymes on appropriately functionalized supports via linkers provide rigidity to the immobilized enzyme structure, ultimately resulting in improved enzyme stability. Protein engineering and immobilization techniques are sequential and compatible approaches for the improvement of enzyme properties. The present review highlights and summarizes various studies that have aimed to improve the biochemical properties of industrially significant enzymes.
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Affiliation(s)
- Raushan Kumar Singh
- Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul 143-701, Korea.
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29
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Amore A, Pepe O, Ventorino V, Birolo L, Giangrande C, Faraco V. Cloning and recombinant expression of a cellulase from the cellulolytic strain Streptomyces sp. G12 isolated from compost. Microb Cell Fact 2012; 11:164. [PMID: 23267666 PMCID: PMC3549853 DOI: 10.1186/1475-2859-11-164] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 12/16/2012] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The use of lignocellulosic materials for second generation ethanol production would give several advantages such as minimizing the conflict between land use for food and fuel production, providing less expensive raw materials than conventional agricultural feedstock, allowing lower greenhouse gas emissions than those of first generation ethanol. However, cellulosic biofuels are not produced at a competitive level yet, mainly because of the high production costs of the cellulolytic enzymes. Therefore, this study was aimed at discovering new cellulolytic microorganisms and enzymes. RESULTS Different bacteria isolated from raw composting materials obtained from vegetable processing industry wastes were screened for their cellulolytic activity on solid medium containing carboxymethylcellulose. Four strains belonging to the actinomycetes group were selected on the basis of their phenotypic traits and cellulolytic activity on solid medium containing carboxymethylcellulose. The strain showing the highest cellulolytic activity was identified by 16S rRNA sequencing as belonging to Streptomyces genus and it was designated as Streptomyces sp. strain G12. Investigating the enzymes responsible for cellulase activity produced by Streptomyces G12 by proteomic analyses, two endoglucanases were identified. Gene coding for one of these enzymes, named CelStrep, was cloned and sequenced. Molecular analysis showed that the celstrep gene has an open reading frame encoding a protein of 379 amino acid residues, including a signal peptide of 37 amino acid residues. Comparison of deduced aminoacidic sequence to the other cellulases indicated that the enzyme CelStrep can be classified as a family 12 glycoside hydrolase. Heterologous recombinant expression of CelStrep was carried out in Escherichia coli, and the active recombinant enzyme was purified from culture supernatant and characterized. It catalyzes the hydrolysis of carboxymethylcellulose following a Michaelis-Menten kinetics with a KM of 9.13 mg/ml and a vmax of 3469 μM min-1. The enzyme exhibits a half life of around 24 h and 96 h at 60°C and 50°C, respectively and shows a retention of around 80% of activity after 96 h at 40°C. CONCLUSIONS In this manuscript, we describe the isolation of a new cellulolytic strain, Streptomyces sp. G12, from industrial waste based compost, the identification of the enzymes putatively responsible for its cellulolytic activity, the cloning and the recombinant expression of the gene coding for the Streptomyces sp. G12 cellulase CelStrep, that was characterized showing to exhibit a relevant thermoresistance increasing its potential for cellulose conversion.
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Affiliation(s)
- Antonella Amore
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S, Angelo, via Cintia, 4, 80126, Naples, Italy
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Yennamalli RM, Wolt JD, Sen TZ. Dynamics of endoglucanase catalytic domains: implications towards thermostability. J Biomol Struct Dyn 2012; 29:509-26. [PMID: 22066537 DOI: 10.1080/07391102.2011.10507402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Thermostable endoglucanases play a crucial role in the production of biofuels to breakdown plant cellulose. Analyzing their structure-dynamics relationship can inform about the origins of their thermostability. Although tertiary structures of many endoglucanase proteins are available, the relationship between thermostability, structure, and dynamics is not explored fully. We have generated elastic network models for thermostable and mesostable endoglucanases with the (αβ)₈ fold in substrate bound and unbound states. The comparative analyses shed light on the relation between protein dynamics, thermostability, and substrate binding. We observed specific differences in the dynamic behavior of catalytic residues in slow modes: while both the nucleophile and the acid/base donor residues show positively correlated motions in the thermophile, their dynamics is uncoupled in the mesophile. Our proof-of-concept comparison study suggests that global dynamics can be harnessed to further our understanding of thermostability.
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Affiliation(s)
- Ragothaman M Yennamalli
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
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31
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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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32
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Harnessing glycosylation to improve cellulase activity. Curr Opin Biotechnol 2012; 23:338-45. [DOI: 10.1016/j.copbio.2011.11.030] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/24/2011] [Accepted: 11/26/2011] [Indexed: 11/17/2022]
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33
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Vizoná Liberato M, Cardoso Generoso W, Malagó W, Henrique-Silva F, Polikarpov I. Crystallization and preliminary X-ray diffraction analysis of endoglucanase III from Trichoderma harzianum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:306-9. [PMID: 22442229 PMCID: PMC3310537 DOI: 10.1107/s1744309112000838] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 01/09/2012] [Indexed: 11/06/2023]
Abstract
Endoglucanases are enzymes that hydrolyze cellulose and are important components of the cellulolytic complex. In contrast to other members of the complex, they cleave internal β-1,4-glycosidic bonds in the cellulose polymer, allowing cellulose to be used as an energy source. Since biomass is an important renewable source of energy, the structural and functional characterization of these enzymes is of interest. In this study, endoglucanase III from Trichoderma harzianum was produced in Pichia pastoris and purified. Crystals belonging to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 47.54, b = 55.57, c = 157.3 Å, were obtained by the sitting-drop vapour-diffusion method and an X-ray diffraction data set was collected to 2.07 Å resolution.
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Affiliation(s)
- Marcelo Vizoná Liberato
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, 13566-590 São Carlos-SP, Brazil
| | - Wesley Cardoso Generoso
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Wilson Malagó
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Flávio Henrique-Silva
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luís, km. 235, 13565-905 São Carlos-SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, 13566-590 São Carlos-SP, Brazil
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34
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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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35
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Cheng YS, Ko TP, Huang JW, Wu TH, Lin CY, Luo W, Li Q, Ma Y, Huang CH, Wang AHJ, Liu JR, Guo RT. Enhanced activity of Thermotoga maritima cellulase 12A by mutating a unique surface loop. Appl Microbiol Biotechnol 2011; 95:661-9. [PMID: 22170108 DOI: 10.1007/s00253-011-3791-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 11/20/2011] [Accepted: 11/23/2011] [Indexed: 11/24/2022]
Abstract
Cellulase 12A from Thermotoga maritima (TmCel12A) is a hyperthermostable β-1,4-endoglucanase. We recently determined the crystal structures of TmCel12A and its complexes with oligosaccharides. Here, by using site-directed mutagenesis, the role played by Arg60 and Tyr61 in a unique surface loop of TmCel12A was investigated. The results are consistent with the previously observed hydrogen bonding and stacking interactions between these two residues and the substrate. Interestingly, the mutant Y61G had the highest activity when compared with the wild-type enzyme and the other mutants. It also shows a wider range of working temperatures than does the wild type, along with retention of the hyperthermostability. The k (cat) and K (m) values of Y61G are both higher than those of the wild type. In conjunction with the crystal structure of Y61G-substrate complex, the kinetic data suggest that the higher endoglucanase activity is probably due to facile dissociation of the cleaved sugar moiety at the reducing end. Additional crystallographic analyses indicate that the insertion and deletion mutations at the Tyr61 site did not affect the overall protein structure, but local perturbations might diminish the substrate-binding strength. It is likely that the catalytic efficiency of TmCel12A is a subtle balance between substrate binding and product release. The activity enhancement by the single mutation of Y61G provides a good example of engineered enzyme for industrial application.
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Affiliation(s)
- Ya-Shan Cheng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
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36
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Cloning and bioinformatics analysis of an endoglucanase gene (Aucel12A) from Aspergillus usamii and its functional expression in Pichia pastoris. J Ind Microbiol Biotechnol 2011; 39:347-57. [PMID: 21935697 DOI: 10.1007/s10295-011-1039-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 09/05/2011] [Indexed: 10/17/2022]
Abstract
Using 3' and 5' rapid amplification of cDNA ends methods, the full-length cDNA sequence encoding an endo-1,4-β-glucanase of Aspergillus usamii E001 (abbreviated as AuCel12A) was amplified from the total RNA. The clone cDNA sequence of the gene encoding the AuCel12A, named as Aucel12A, is 1,027 bp in length harboring 5' and 3' non-coding regions, as well as a 720 bp of open reading frame that encodes a 16-aa signal peptide, and a 223-aa mature AuCel12A with a theoretical M.W. of 24,294 Da, a calculated pI of 4.15, and one putative N-glycosylation site. The complete DNA sequence of the gene Aucel12A was amplified from the genomic DNA of A. usamii E001 by using the conventional PCR and pUCm-T vector-mediated PCR initially developed in our lab. The clone DNA sequence is 1,576 bp in length, consisting of a 5' flanking regulatory region, three exons, and two introns with sizes of 50 and 66 bp. The cDNA fragment encoding the mature AuCel12A was expressed in a fully active form in Pichia pastoris. One P. pastoris transformant expressing the highest recombinant AuCel12A (rAuCel12A) activity, labeled as P. pastoris GSCel2-1, was chosen for subsequent studies. Integration of the Aucel12A into P. pastoris genome was confirmed by PCR analysis using 5'- and 3'-AOX1 primers. SDS-PAGE and enzyme activity assays demonstrated that the rAuCel12A, a glycosylated protein with an apparent M.W. of 27.0 kDa and a carbohydrate content of 4.82%, was secreted into the culture medium. The purified rAuCel12A displayed the highest activity at pH 5.0 and 60°C. It was highly stable at a pH range of 3.5-7.0, and at a temperature of 55°C or below. Its activity was not significantly affected by an array of metal ions and EDTA, but inhibited by Ag⁺, Hg²⁺ and Fe²⁺. The K(m) and V(max) of the rAuCel12A, towards carboxymethylcellulose-Na (CMC-Na) at pH 5.0 and 50°C were 4.85 mg/ml and 160.5 U/mg, respectively.
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37
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Badieyan S, Bevan DR, Zhang C. Study and design of stability in GH5 cellulases. Biotechnol Bioeng 2011; 109:31-44. [PMID: 21809329 DOI: 10.1002/bit.23280] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/30/2011] [Accepted: 07/11/2011] [Indexed: 11/07/2022]
Abstract
Thermostable enzymes that hydrolyze lignocellulosic materials provide potential advantages in process configuration and enhancement of production efficiency over their mesophilic counterparts in the bioethanol industry. In this study, the dynamics of β-1,4-endoglucanases (EC: 3.2.1.4) from family 5 of glycoside hydrolases (GH5) were investigated computationally. The conformational flexibility of 12 GH5 cellulases, ranging from psychrophilic to hyperthermophilic, was investigated by molecular dynamics (MD) simulations at elevated temperatures. The results indicated that the protein flexibility and optimum activity temperatures are appreciably correlated. Intra-protein interactions, packing density and solvent accessible area were further examined in crystal structures to investigate factors that are possibly involved in higher rigidity of thermostable cellulases. The MD simulations and the rules learned from analyses of stabilizing factors were used in design of mutations toward the thermostabilization of cellulase C, one of the GH5 endoglucanases. This enzyme was successfully stabilized both chemically and thermally by introduction of a new disulfide cross-link to its highly mobile 56-amino acid subdomain.
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Affiliation(s)
- Somayesadat Badieyan
- Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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38
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Yennamalli RM, Rader AJ, Wolt JD, Sen TZ. Thermostability in endoglucanases is fold-specific. BMC STRUCTURAL BIOLOGY 2011; 11:10. [PMID: 21291533 PMCID: PMC3047435 DOI: 10.1186/1472-6807-11-10] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 02/03/2011] [Indexed: 12/03/2022]
Abstract
Background Endoglucanases are usually considered to be synergistically involved in the initial stages of cellulose breakdown-an essential step in the bioprocessing of lignocellulosic plant materials into bioethanol. Despite their economic importance, we currently lack a basic understanding of how some endoglucanases can sustain their ability to function at elevated temperatures required for bioprocessing, while others cannot. In this study, we present a detailed comparative analysis of both thermophilic and mesophilic endoglucanases in order to gain insights into origins of thermostability. We analyzed the sequences and structures for sets of endoglucanase proteins drawn from the Carbohydrate-Active enZymes (CAZy) database. Results Our results demonstrate that thermophilic endoglucanases and their mesophilic counterparts differ significantly in their amino acid compositions. Strikingly, these compositional differences are specific to protein folds and enzyme families, and lead to differences in intramolecular interactions in a fold-dependent fashion. Conclusions Here, we provide fold-specific guidelines to control thermostability in endoglucanases that will aid in making production of biofuels from plant biomass more efficient.
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Affiliation(s)
- Ragothaman M Yennamalli
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
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39
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Cheng YS, Ko TP, Wu TH, Ma Y, Huang CH, Lai HL, Wang AHJ, Liu JR, Guo RT. Crystal structure and substrate-binding mode of cellulase 12A from Thermotoga maritima. Proteins 2011; 79:1193-204. [PMID: 21268113 DOI: 10.1002/prot.22953] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/10/2010] [Accepted: 11/17/2010] [Indexed: 11/12/2022]
Abstract
Cellulases have been used in many applications to treat various carbohydrate-containing materials. Thermotoga maritima cellulase 12A (TmCel12A) belongs to the GH12 family of glycoside hydrolases. It is a β-1,4-endoglucanase that degrades cellulose molecules into smaller fragments, facilitating further utilization of the carbohydrate. Because of its hyperthermophilic nature, the enzyme is especially suitable for industrial applications. Here the crystal structure of TmCel12A was determined by using an active-site mutant E134C and its mercury-containing derivatives. It adopts a β-jellyroll protein fold typical of the GH12-family enzymes, with two curved β-sheets A and B and a central active-site cleft. Structural comparison with other GH12 enzymes shows significant differences, as found in two longer and highly twisted β-strands B8 and B9 and several loops. A unique Loop A3-B3 that contains Arg60 and Tyr61 stabilizes the substrate by hydrogen bonding and stacking, as observed in the complex crystals with cellotetraose and cellobiose. The high-resolution structures allow clear elucidation of the network of interactions between the enzyme and its substrate. The sugar residues bound to the enzyme appear to be more ordered in the -2 and -1 subsites than in the +1, +2 and -3 subsites. In the E134C crystals the bound -1 sugar at the cleavage site consistently show the α-anomeric configuration, implicating an intermediate-like structure.
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Affiliation(s)
- Ya-Shan Cheng
- Institute of Biotechnology, National Taiwan University, Taiwan
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40
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Anbar M, Lamed R, Bayer E. Thermostability Enhancement of Clostridium thermocellum Cellulosomal Endoglucanase Cel8A by a Single Glycine Substitution. ChemCatChem 2010. [DOI: 10.1002/cctc.201000112] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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41
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Gallardo O, Pastor FIJ, Polaina J, Diaz P, Łysek R, Vogel P, Isorna P, González B, Sanz-Aparicio J. Structural insights into the specificity of Xyn10B from Paenibacillus barcinonensis and its improved stability by forced protein evolution. J Biol Chem 2009; 285:2721-33. [PMID: 19940147 DOI: 10.1074/jbc.m109.064394] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Paenibacillus barcinonensis is a soil bacterium bearing a complex set of enzymes for xylan degradation, including several secreted enzymes and Xyn10B, one of the few intracellular xylanases reported to date. The crystal structure of Xyn10B has been determined by x-ray analysis. The enzyme folds into the typical (beta/alpha)(8) barrel of family 10 glycosyl hydrolases (GH10), with additional secondary structure elements within the beta/alpha motifs. One of these loops -L7- located at the beta7 C terminus, was essential for xylanase activity as its partial deletion yielded an inactive enzyme. The loop contains residues His(249)-Glu(250), which shape a pocket opened to solvent in close proximity to the +2 subsite, which has not been described in other GH10 enzymes. This wide cavity at the +2 subsite, where methyl-2,4-pentanediol from the crystallization medium was found, is a noteworthy feature of Xyn10B, as compared with the narrow crevice described for other GH10 xylanases. Docking analysis showed that this open cavity can accommodate glucuronic acid decorations of xylo-oligosaccharides. Co-crystallization experiments with conduramine derivative inhibitors supported the importance of this open cavity at the +2 subsite for Xyn10B activity. Several mutant derivatives of Xyn10B with improved thermal stability were obtained by forced evolution. Among them, mutant xylanases S15L and M93V showed increased half-life, whereas the double mutant S15L/M93V exhibited a further increase in stability, showing a 20-fold higher heat resistance than the wild type xylanase. All the mutations obtained were located on the surface of Xyn10B. Replacement of a Ser by a Leu residue in mutant xylanase S15L can increase hydrophobic packing efficiency and fill a superficial indentation of the protein, giving rise to a more compact structure of the enzyme.
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Affiliation(s)
- Oscar Gallardo
- Department of Microbiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain
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Directed evolution of endoglucanase III (Cel12A) from Trichoderma reesei. Appl Microbiol Biotechnol 2009; 83:649-57. [DOI: 10.1007/s00253-009-1901-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 01/22/2009] [Accepted: 01/25/2009] [Indexed: 12/01/2022]
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Nakazawa H, Okada K, Kobayashi R, Kubota T, Onodera T, Ochiai N, Omata N, Ogasawara W, Okada H, Morikawa Y. Characterization of the catalytic domains of Trichoderma reesei endoglucanase I, II, and III, expressed in Escherichia coli. Appl Microbiol Biotechnol 2008; 81:681-9. [DOI: 10.1007/s00253-008-1667-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 08/11/2008] [Accepted: 08/12/2008] [Indexed: 11/30/2022]
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44
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Replacement of the active surface of a thermophile protein by that of a homologous mesophile protein through structure-guided ‘protein surface grafting’. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1771-6. [DOI: 10.1016/j.bbapap.2008.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 05/10/2008] [Accepted: 05/13/2008] [Indexed: 11/19/2022]
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45
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LeMaster DM, Hernández G. Additivity of Differential Conformational Dynamics in Hyperthermophile/Mesophile Rubredoxin Chimeras as Monitored by Hydrogen Exchange. Chembiochem 2006; 7:1886-9. [PMID: 17068837 DOI: 10.1002/cbic.200600276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David M LeMaster
- Wadsworth Center, New York State Department of Health, University at Albany-SUNY, Empire State Plaza, Albany, NY 12201-0509, USA
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Huang Y, Krauss G, Cottaz S, Driguez H, Lipps G. A highly acid-stable and thermostable endo-beta-glucanase from the thermoacidophilic archaeon Sulfolobus solfataricus. Biochem J 2005; 385:581-8. [PMID: 15456402 PMCID: PMC1134732 DOI: 10.1042/bj20041388] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The thermoacidophilic archaeon Sulfolobus solfataricus P2 encodes three hypothetic endo-beta-glucanases, SSO1354, SSO1949 and SSO2534. We cloned and expressed the gene sso1949 encoding the 334 amino acids containing protein SSO1949, which can be classified as a member of glycoside hydrolase family 12. The purified recombinant enzyme hydrolyses carboxymethylcellulose as well as cello-oligomers, with cellobiose and cellotriose as main reaction products. By following the hydrolysis of a fluorescently labelled cellohexaoside under a wide variety of conditions, we show that SSO1949 is a unique extremophilic enzyme. This archaeal enzyme has a pH optimum of approx. pH 1.8 and a temperature optimum of approx. 80 degrees C. Furthermore, the enzyme is thermostable, with a half-life of approx. 8 h at 80 degrees C and pH 1.8. The thermostability is strongly pH-dependent. At neutral pH, the thermal inactivation rate is nearly two orders of magnitude higher than at pH 1.8. Homology modelling suggests that the catalytic domain of SSO1949 has a similar fold to other mesophilic, acidophilic and neutral cellulases. The presence of a signal peptide indicates that SSO1949 is a secreted protein, which enables S. solfataricus to use cellulose as an external carbon source. It appears that SSO1949 is perfectly adapted to the extreme environment in solfataric pools. A cellulolytic enzyme with such a combination of stability and activity at high temperatures and low pH has not been described so far and could be a valuable tool for the large-scale hydrolysis of cellulose under acidic conditions.
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Affiliation(s)
- Yiwei Huang
- *Institute of Biochemistry, University of Bayreuth, Universitätstrasse 30, 95447 Bayreuth, Germany
| | - Gerhard Krauss
- *Institute of Biochemistry, University of Bayreuth, Universitätstrasse 30, 95447 Bayreuth, Germany
| | - Sylvain Cottaz
- †Centre de Recherches sur les Macromolécules Végétales, FR CNRS 2607, BP 53, 38041 Grenoble cedex 9, France
| | - Hugues Driguez
- †Centre de Recherches sur les Macromolécules Végétales, FR CNRS 2607, BP 53, 38041 Grenoble cedex 9, France
| | - Georg Lipps
- *Institute of Biochemistry, University of Bayreuth, Universitätstrasse 30, 95447 Bayreuth, Germany
- To whom correspondence should be addressed (email )
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Sandgren M, Ståhlberg J, Mitchinson C. Structural and biochemical studies of GH family 12 cellulases: improved thermal stability, and ligand complexes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2004; 89:246-91. [PMID: 15950056 DOI: 10.1016/j.pbiomolbio.2004.11.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this review we will describe how we have gathered structural and biochemical information from several homologous cellulases from one class of glycoside hydrolases (GH family 12), and used this information within the framework of a protein-engineering program for the design of new variants of these enzymes. These variants have been characterized to identify some of the positions and the types of mutations in the enzymes that are responsible for some of the biochemical differences in thermal stability and activity between the homologous enzymes. In this process we have solved the three-dimensional structure of four of these homologous GH 12 cellulases: Three fungal enzymes, Humicola grisea Cel12A, Hypocrea jecorina Cel12A and Hypocrea schweinitzii Cel12A, and one bacterial, Streptomyces sp. 11AG8 Cel12A. We have also determined the three-dimensional structures of the two most stable H. jecorina Cel12A variants. In addition, four ligand-complex structures of the wild-type H. grisea Cel12A enzyme have been solved and have made it possible to characterize some of the interactions between substrate and enzyme. The structural and biochemical studies of these related GH 12 enzymes, and their variants, have provided insight on how specific residues contribute to protein thermal stability and enzyme activity. This knowledge can serve as a structural toolbox for the design of Cel12A enzymes with specific properties and features suited to existing or new applications.
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Affiliation(s)
- Mats Sandgren
- Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Husargatan 3, Box 596, SE-751 24 Uppsala, Sweden.
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Eijsink VGH, Bjørk A, Gåseidnes S, Sirevåg R, Synstad B, van den Burg B, Vriend G. Rational engineering of enzyme stability. J Biotechnol 2004; 113:105-20. [PMID: 15380651 DOI: 10.1016/j.jbiotec.2004.03.026] [Citation(s) in RCA: 326] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 02/16/2004] [Accepted: 03/04/2004] [Indexed: 11/19/2022]
Abstract
During the past 15 years there has been a continuous flow of reports describing proteins stabilized by the introduction of mutations. These reports span a period from pioneering rational design work on small enzymes such as T4 lysozyme and barnase to protein design, and directed evolution. Concomitantly, the purification and characterization of naturally occurring hyperstable proteins has added to our understanding of protein stability. Along the way, many strategies for rational protein stabilization have been proposed, some of which (e.g. entropic stabilization by introduction of prolines or disulfide bridges) have reasonable success rates. On the other hand, comparative studies and efforts in directed evolution have revealed that there are many mutational strategies that lead to high stability, some of which are not easy to define and rationalize. Recent developments in the field include increasing awareness of the importance of the protein surface for stability, as well as the notion that normally a very limited number of mutations can yield a large increase in stability. Another development concerns the notion that there is a fundamental difference between the "laboratory stability" of small pure proteins that unfold reversibly and completely at high temperatures and "industrial stability", which is usually governed by partial unfolding processes followed by some kind of irreversible inactivation process (e.g. aggregation). Provided that one has sufficient knowledge of the mechanism of thermal inactivation, successful and efficient rational stabilization of enzymes can be achieved.
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Affiliation(s)
- Vincent G H Eijsink
- Department of Chemistry, Biotechnology and Food Science, Agricultural University of Norway, PO Box 5040, N-1432 As.
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Bjørk A, Dalhus B, Mantzilas D, Sirevåg R, Eijsink VGH. Large improvement in the thermal stability of a tetrameric malate dehydrogenase by single point mutations at the dimer-dimer interface. J Mol Biol 2004; 341:1215-26. [PMID: 15321717 DOI: 10.1016/j.jmb.2004.06.079] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Revised: 06/06/2004] [Accepted: 06/22/2004] [Indexed: 10/26/2022]
Abstract
The stability of tetrameric malate dehydrogenase from the green phototrophic bacterium Chloroflexus aurantiacus (CaMDH) is at least in part determined by electrostatic interactions at the dimer-dimer interface. Since previous studies had indicated that the thermal stability of CaMDH becomes lower with increasing pH, attempts were made to increase the stability by removal of (excess) negative charge at the dimer-dimer interface. Mutation of Glu165 to Gln or Lys yielded a dramatic increase in thermal stability at pH 7.5 (+23.6 -- + 23.9 degrees C increase in apparent t(m)) and a more moderate increase at pH 4.4 (+4.6 -- + 5.4 degrees C). The drastically increased stability at neutral pH was achieved without forfeiture of catalytic performance at low temperatures. The crystal structures of the two mutants showed only minor structural changes close to the mutated residues, and indicated that the observed stability effects are solely due to subtle changes in the complex network of electrostatic interactions in the dimer-dimer interface. Both mutations reduced the concentration dependency of thermal stability, suggesting that the oligomeric structure had been reinforced. Interestingly, the two mutations had similar effects on stability, despite the charge difference between the introduced side-chains. Together with the loss of concentration dependency, this may indicate that both E165Q and E165K stabilize CaMDH to such an extent that disruption of the inter-dimer electrostatic network around residue 165 no longer limits kinetic thermal stability.
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Affiliation(s)
- Alexandra Bjørk
- Department of Molecular Biosciences, University of Oslo, P.O. Box 1041, Blindern, N-0316 Oslo, Norway.
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50
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Sandgren M, Berglund GI, Shaw A, Ståhlberg J, Kenne L, Desmet T, Mitchinson C. Crystal Complex Structures Reveal How Substrate is Bound in the −4 to the +2 Binding Sites of Humicola grisea Cel12A. J Mol Biol 2004; 342:1505-17. [PMID: 15364577 DOI: 10.1016/j.jmb.2004.07.098] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 07/19/2004] [Accepted: 07/30/2004] [Indexed: 11/27/2022]
Abstract
As part of an ongoing enzyme discovery program to investigate the properties and catalytic mechanism of glycoside hydrolase family 12 (GH 12) endoglucanases, a GH family that contains several cellulases that are of interest in industrial applications, we have solved four new crystal structures of wild-type Humicola grisea Cel12A in complexes formed by soaking with cellobiose, cellotetraose, cellopentaose, and a thio-linked cellotetraose derivative (G2SG2). These complex structures allow mapping of the non-covalent interactions between the enzyme and the glucosyl chain bound in subsites -4 to +2 of the enzyme, and shed light on the mechanism and function of GH 12 cellulases. The unhydrolysed cellopentaose and the G2SG2 cello-oligomers span the active site of the catalytically active H.grisea Cel12A enzyme, with the pyranoside bound in subsite -1 displaying a S31 skew boat conformation. After soaking in cellotetraose, the cello-oligomer that is found bound in site -4 to -1 contains a beta-1,3-linkage between the two cellobiose units in the oligomer, which is believed to have been formed by a transglycosylation reaction that has occurred during the ligand soak of the protein crystals. The close fit of this ligand and the binding sites occupied suggest a novel mixed beta-glucanase activity for this enzyme.
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Affiliation(s)
- Mats Sandgren
- Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Box 596, SE-751 24 Uppsala, Sweden.
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