1
|
Tian W, Zhang Z, Yang C, Li P, Xiao J, Wang R, Du P, Li N, Wang J. Engineering mesophilic GH11 xylanase from Cellulomonas flavigena by rational design of N-terminus substitution. Front Bioeng Biotechnol 2022; 10:1044291. [DOI: 10.3389/fbioe.2022.1044291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Xylanase, a glycoside hydrolase, is widely used in the food, papermaking, and textile industries; however, most xylanases are inactive at high temperatures. In this study, a xylanase gene, CFXyl3, was cloned from Cellulomonas flavigena and expressed in Escherichia coli BL21 (DE3). To improve the thermostability of xylanase, four hybrid xylanases with enhanced thermostability (designated EcsXyl1–4) were engineered from CFXyl3, guided by primary and 3D structure analyses. The optimal temperature of CFXyl3 was improved by replacing its N-terminus with the corresponding area of SyXyn11P, a xylanase that belongs to the hyperthermostable GH11 family. The optimal temperatures of the hybrid xylanases EcsXyl1–4 were 60, 60, 65, and 85°C, respectively. The optimal temperature of EcsXyl4 was 30 C higher than that of CFXyl3 (55°C) and its melting temperature was 34.5°C higher than that of CFXyl3. After the hydrolysis of beechwood xylan, the main hydrolysates were xylotetraose, xylotriose, and xylobiose; thus, these hybrid xylanases could be applied to prebiotic xylooligosaccharide manufacturing.
Collapse
|
2
|
Wang L, Cao K, Pedroso MM, Wu B, Gao Z, He B, Schenk G. Sequence- and structure-guided improvement of the catalytic performance of a GH11 family xylanase from Bacillus subtilis. J Biol Chem 2021; 297:101262. [PMID: 34600889 PMCID: PMC8546418 DOI: 10.1016/j.jbc.2021.101262] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 12/02/2022] Open
Abstract
Xylanases produce xylooligosaccharides from xylan and have thus attracted increasing attention for their usefulness in industrial applications. Previously, we demonstrated that the GH11 xylanase XynLC9 from Bacillus subtilis formed xylobiose and xylotriose as the major products with negligible production of xylose when digesting corncob-extracted xylan. Here, we aimed to improve the catalytic performance of XynLC9 via protein engineering. Based on the sequence and structural comparisons of XynLC9 with the xylanases Xyn2 from Trichoderma reesei and Xyn11A from Thermobifida fusca, we identified the N-terminal residues 5-YWQN-8 in XynLC9 as engineering hotspots and subjected this sequence to site saturation and iterative mutagenesis. The mutants W6F/Q7H and N8Y possessed a 2.6- and 1.8-fold higher catalytic activity than XynLC9, respectively, and both mutants were also more thermostable. Kinetic measurements suggested that W6F/Q7H and N8Y had lower substrate affinity, but a higher turnover rate (kcat), which resulted in increased catalytic efficiency than WT XynLC9. Furthermore, the W6F/Q7H mutant displayed a 160% increase in the yield of xylooligosaccharides from corncob-extracted xylan. Molecular dynamics simulations revealed that the W6F/Q7H and N8Y mutations led to an enlarged volume and surface area of the active site cleft, which provided more space for substrate entry and product release and thus accelerated the catalytic activity of the enzyme. The molecular evolution approach adopted in this study provides the design of a library of sequences that captures functional diversity in a limited number of protein variants.
Collapse
Affiliation(s)
- Lijuan Wang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, China
| | - Kun Cao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, China
| | - Marcelo Monteiro Pedroso
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Bin Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, China.
| | - Zhen Gao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, China.
| | - Bingfang He
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, China
| | - Gerhard Schenk
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| |
Collapse
|
3
|
Li G, Zhou X, Li Z, Liu Y, Liu D, Miao Y, Wan Q, Zhang R. Significantly improving the thermostability of a hyperthermophilic GH10 family xylanase XynAF1 by semi-rational design. Appl Microbiol Biotechnol 2021; 105:4561-4576. [PMID: 34014347 DOI: 10.1007/s00253-021-11340-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/16/2021] [Accepted: 05/09/2021] [Indexed: 11/28/2022]
Abstract
Xylanases have a broad range of applications in industrial biotechnologies, which require the enzymes to resist the high-temperature environments. The majority of xylanases have maximum activity at moderate temperatures, which limited their potential applications in industries. In this study, a thermophilic GH10 family xylanase XynAF1 from the high-temperature composting strain Aspergillus fumigatus Z5 was characterized and engineered to further improve its thermostability. XynAF1 has the optimal reaction temperature of 90 °C. The crystal structure of XynAF1 was obtained by X-ray diffraction after heterologous expression, purification, and crystallization. The high-resolution X-ray crystallographic structure of the protein-product complex was obtained by soaking the apo-state crystal with xylotetraose. Structure analysis indicated that XynAF1 has a rigid skeleton, which helps to maintain the hyperthermophilic characteristic. The homologous structure analysis and the catalytic center mutant construction of XynAF1 indicated the conserved catalytic center contributed to the high optimum catalytic temperature. The amino acids in the surface of xylanase XynAF1 which might influence the enzyme thermostability were identified by the structure analysis. Combining the rational design with the saturation mutation at the high B-value regions, the integrative mutant XynAF1-AC with a 6-fold increase of thermostability was finally obtained. This study efficiently improved the thermostability of a GH10 family xylanase by semi-rational design, which provided a new biocatalyst for high-temperature biotechnological applications. KEY POINTS: • Obtained the crystal structure of GH10 family hyperthermophilic xylanase XynAF1. • Shed light on the understanding of the GH10 family xylanase thermophilic mechanism. • Constructed a 6-fold increased thermostability recombinant xylanase.
Collapse
Affiliation(s)
- Guangqi Li
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.,Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Xuan Zhou
- National Agricultural Technology Extension and Service Center, Beijing, 100125, People's Republic of China
| | - Zhihong Li
- College of Science, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Dongyang Liu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Youzhi Miao
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Qun Wan
- College of Science, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. .,The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China. .,Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
| |
Collapse
|
4
|
Cui H, Eltoukhy L, Zhang L, Markel U, Jaeger K, Davari MD, Schwaneberg U. Less Unfavorable Salt Bridges on the Enzyme Surface Result in More Organic Cosolvent Resistance. Angew Chem Int Ed Engl 2021; 60:11448-11456. [PMID: 33687787 PMCID: PMC8252522 DOI: 10.1002/anie.202101642] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Indexed: 11/06/2022]
Abstract
Biocatalysis for the synthesis of fine chemicals is highly attractive but usually requires organic (co-)solvents (OSs). However, native enzymes often have low activity and resistance in OSs and at elevated temperatures. Herein, we report a smart salt bridge design strategy for simultaneously improving OS resistance and thermostability of the model enzyme, Bacillus subtilits Lipase A (BSLA). We combined comprehensive experimental studies of 3450 BSLA variants and molecular dynamics simulations of 36 systems. Iterative recombination of four beneficial substitutions yielded superior resistant variants with up to 7.6-fold (D64K/D144K) improved resistance toward three OSs while exhibiting significant thermostability (thermal resistance up to 137-fold, and half-life up to 3.3-fold). Molecular dynamics simulations revealed that locally refined flexibility and strengthened hydration jointly govern the highly increased resistance in OSs and at 50-100 °C. The salt bridge redesign provides protein engineers with a powerful and likely general approach to design OSs- and/or thermal-resistant lipases and other α/β-hydrolases.
Collapse
Affiliation(s)
- Haiyang Cui
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
- DWI Leibniz-Institute for Interactive MaterialsForckenbeckstrasse 5052074AachenGermany
| | - Lobna Eltoukhy
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
| | - Lingling Zhang
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
- Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesWest 7th Avenue 32, Tianjin Airport Economic Area300308TianjinChina
| | - Ulrich Markel
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
| | - Karl‐Erich Jaeger
- Institute of Molecular Enzyme TechnologyHeinrich Heine University DüsseldorfWilhelm Johnen Strasse52426JülichGermany
- Institute of Bio-and Geosciences IBG 1: BiotechnologyForschungszentrum Jülich GmbHWilhelm Johnen Strasse52426JülichGermany
| | - Mehdi D. Davari
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
| | - Ulrich Schwaneberg
- Institute of BiotechnologyRWTH Aachen UniversityWorringer Weg 352074AachenGermany
- DWI Leibniz-Institute for Interactive MaterialsForckenbeckstrasse 5052074AachenGermany
| |
Collapse
|
5
|
Cui H, Eltoukhy L, Zhang L, Markel U, Jaeger K, Davari MD, Schwaneberg U. Less Unfavorable Salt Bridges on the Enzyme Surface Result in More Organic Cosolvent Resistance. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101642] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Haiyang Cui
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
- DWI Leibniz-Institute for Interactive Materials Forckenbeckstrasse 50 52074 Aachen Germany
| | - Lobna Eltoukhy
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
| | - Lingling Zhang
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences West 7th Avenue 32, Tianjin Airport Economic Area 300308 Tianjin China
| | - Ulrich Markel
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
| | - Karl‐Erich Jaeger
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf Wilhelm Johnen Strasse 52426 Jülich Germany
- Institute of Bio-and Geosciences IBG 1: Biotechnology Forschungszentrum Jülich GmbH Wilhelm Johnen Strasse 52426 Jülich Germany
| | - Mehdi D. Davari
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology RWTH Aachen University Worringer Weg 3 52074 Aachen Germany
- DWI Leibniz-Institute for Interactive Materials Forckenbeckstrasse 50 52074 Aachen Germany
| |
Collapse
|
6
|
Liu W, Ma C, Liu W, Zheng Y, Chen CC, Liang A, Luo X, Li Z, Ma W, Song Y, Guo RT, Zhang T. Functional and structural investigation of a novel β-mannanase BaMan113A from Bacillus sp. N16-5. Int J Biol Macromol 2021; 182:899-909. [PMID: 33865894 DOI: 10.1016/j.ijbiomac.2021.04.075] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/30/2021] [Accepted: 04/13/2021] [Indexed: 10/21/2022]
Abstract
Mannan is an important renewable resource whose backbone can be hydrolyzed by β-mannanases to generate manno-oligosaccharides of various sizes. Only a few glycoside hydrolase (GH) 113 family β-mannanases have been functionally and structurally characterize. Here, we report the function and structure of a novel GH113 β-mannanase from Bacillus sp. N16-5 (BaMan113A). BaMan113A exhibits a substrate preference toward manno-oligosaccharides and releases mannose and mannobiose as main hydrolytic products. The crystal structure of BaMan113A suggest that the enzyme shows a semi-enclosed substrate-binding cleft and the amino acids surrounding the +2 subsite form a steric barrier to terminate the substrate-binding tunnel. Based on these structural features, we conducted mutagenesis to engineer BaMan113A to remove the steric hindrance of the substrate-binding tunnel. We found that F101E and N236Y variants exhibit increased specific activity toward mannans comparing to the wild-type enzyme. Meanwhile, the product profiles of these two variants toward polysaccharides changed from mannose to a series of manno-oligosaccharides. The crystal structure of variant N236Y was also determined to illustrate the molecular basis underlying the mutation. In conclusion, we report the functional and structural features of a novel GH113 β-mannanase, and successfully improved its endo-acting activity by using structure-based engineering.
Collapse
Affiliation(s)
- Wenting Liu
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Cuiping Ma
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Weidong Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yingying Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Chun-Chi Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Ailing Liang
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Xuegang Luo
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhongyuan Li
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Wenjian Ma
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yajian Song
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Rey-Ting Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Tongcun Zhang
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| |
Collapse
|
7
|
Yang J, Ma T, Shang-Guan F, Han Z. Improving the catalytic activity of thermostable xylanase from Thermotoga maritima via mutagenesis of non-catalytic residues at glycone subsites. Enzyme Microb Technol 2020; 139:109579. [PMID: 32732029 DOI: 10.1016/j.enzmictec.2020.109579] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/31/2020] [Accepted: 04/14/2020] [Indexed: 10/24/2022]
Abstract
Endo-β-1,4-xylanase from Thermotoga maritima, TmxB, is an industrially attractive enzyme due to its extreme thermostability. To improve its application value, four variants were designed on the basis of multiple sequence and three-dimensional structure alignments. Wild-type TmxB (wt-TmxB) and its mutants were produced via a Pichia pastoris expression system. Among four single-site mutants, the tyrosine substitution of a threonine residue (T74Y) at putative -3/-4 subsite led to a 1.3-fold increase in specific activity at 40 °C - 100 °C and pH 5 for 5 min, with beechwood xylan as the substrate. T74Y had an improved catalytic efficiency (kcat/Km), being 1.6 times that of wt-TmxB. Variants DY (two amino acid insertions) and N68Q displayed a slight increase (1.2 fold) and dramatic decline (1.7 fold) in catalytic efficiency, respectively. Mutant E67Y was totally inactive under all test conditions. Structural modeling and docking simulation elucidated structural insights into the molecular mechanism of activity changes for these TmxB variants. This study helps in further understanding the roles of the non-catalytic amino acids at the glycone subsites of xylanases from glycoside hydrolase family 10.
Collapse
Affiliation(s)
- Jiangke Yang
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Tengfei Ma
- School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fang Shang-Guan
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Zhenggang Han
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
| |
Collapse
|
8
|
A thermophilic and thermostable xylanase from Caldicoprobacter algeriensis: Recombinant expression, characterization and application in paper biobleaching. Int J Biol Macromol 2020; 164:808-817. [PMID: 32698070 DOI: 10.1016/j.ijbiomac.2020.07.162] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/23/2020] [Accepted: 07/14/2020] [Indexed: 01/11/2023]
Abstract
A novel xylanase gene xynBCA, encoding a polypeptide of 439 residues (XynBCA), was cloned from Caldicoprobacter algeriensis genome and recombinantly expressed in Escherichia coli BL21(DE3). The amino acid sequence analysis showed that XynBCA belongs to the glycoside hydrolase family 10. The purified recombinant enzyme has a monomeric structure of 52 kDa. It is active and stable in a wide range of pH from 3 to 10 with a maximum activity at 6.5. Interestingly, XynBCA was highly thermoactive with an optimum temperature of 80 °C, thermostable with a half-life of 20 min at 80 °C. The specific activity was 117 U mg-1, while the Km and Vmax were 1.247 mg ml-1, and 114.7 μmol min-1 mg-1, respectively. The investigation of XynBCA in kraft pulp biobleaching experiments showed effectiveness in releasing reducing sugars and chromophores, with best achievements at 100 U g-1 of pulp and 1 h of incubation. The comparative molecular modeling studies with the less thermostable Xylanase B from Clostridium stercorarium, revealed extra charged residues at the surface of XynBCA potentially participating in the formation of intermolecular hydrogen bonds with solvent molecules or generating salt bridges, therefore contributing to the higher thermal stability.
Collapse
|
9
|
Li G, Chen X, Zhou X, Huang R, Li L, Miao Y, Liu D, Zhang R. Improvement of GH10 family xylanase thermostability by introducing of an extra α-helix at the C-terminal. Biochem Biophys Res Commun 2019; 515:417-422. [DOI: 10.1016/j.bbrc.2019.05.163] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 05/27/2019] [Indexed: 10/26/2022]
|
10
|
Salt bridges are pivotal for the kinetic stability of GH26 endo-mannanase (ManB-1601). Int J Biol Macromol 2019; 133:1236-1241. [DOI: 10.1016/j.ijbiomac.2019.04.175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/24/2019] [Accepted: 04/25/2019] [Indexed: 11/21/2022]
|
11
|
Kim HB, Lee KT, Kim MJ, Lee JS, Kim KS. Identification and characterization of a novel KG42 xylanase (GH10 family) isolated from the black goat rumen-derived metagenomic library. Carbohydr Res 2018; 469:1-9. [PMID: 30170217 DOI: 10.1016/j.carres.2018.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 11/18/2022]
Abstract
This study was conducted to isolate and functionally characterize a novel xylan-degrading enzyme from the microbial metagenomes of black goat rumens. A novel gene, KG42, was isolated from one of the 17 xylan-degrading metagenomic fosmid clones obtained from black goat rumens. The KG42 gene, comprising a 1107 bp open reading frame, encodes a protein composed of 368 amino acids (41 kDa) with a glycosyl hydrolase family 10 (GH10) domain, consisting of a "salad-bowl" shaped tertiary structure (a typical 8-fold α/β barrel (α/β)8) and two catalytic residues. KG42 xylanase protein has at best 40% sequence identity with other homologous GH10 xylanase proteins. The enzyme displayed its optimum activity at pH 5.0 and 50 °C. The enzyme was thermally stable at pH and temperature ranges of 5.0-10.0 and 20-60 °C, respectively. Substrate specificity and hydrolytic patterns implied that the KG42 xylanase functions as an endo-β-1,4-xylanase (EC 3.2.1.8). The KG42 xylanase was also used for the preparation of bifidogenic xylan hydrolysates, demonstrating its potential applications toward preparing prebiotic xylooligosaccharides.
Collapse
Affiliation(s)
- Hye-Bin Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea
| | - Kyung-Tai Lee
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju, 565-851, South Korea
| | - Min-Ju Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea
| | - Jin-Sung Lee
- Department of Biological Sciences, Kyonggi University, Suwon, 442-760, South Korea
| | - Keun-Sung Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea.
| |
Collapse
|