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Chen C, Li X, Lu C, Zhou X, Chen L, Qiu C, Jin Z, Long J. Advances in alginate lyases and the potential application of enzymatic prepared alginate oligosaccharides: A mini review. Int J Biol Macromol 2024; 260:129506. [PMID: 38244735 DOI: 10.1016/j.ijbiomac.2024.129506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 01/22/2024]
Abstract
Alginate is mainly a linear polysaccharide composed of randomly arranged β-D-mannuronic acid and α-L-guluronic acid linked by α, β-(1,4)-glycosidic bonds. Alginate lyases degrade alginate mainly adopting a β-elimination mechanism, breaking the glycosidic bonds between the monomers and forming a double bond between the C4 and C5 sugar rings to produce alginate oligosaccharides consisting of 2-25 monomers, which have various physiological functions. Thus, it can be used for the continuous industrial production of alginate oligosaccharides with a specific degree of polymerization, in accordance with the requirements of green exploitation of marine resources. With the development of structural analysis, the quantity of characterized alginate lyase structures is progressively growing, leading to a concomitant improvement in understanding the catalytic mechanism. Additionally, the use of molecular modification methods including rational design, truncated expression of non-catalytic domains, and recombination of conserved domains can improve the catalytic properties of the original enzyme, enabling researchers to screen out the enzyme with the expected excellent performance with high success rate and less workload. This review presents the latest findings on the catalytic mechanism of alginate lyases and outlines the methods for molecular modifications. Moreover, it explores the connection between the degree of polymerization and the physiological functions of alginate oligosaccharides, providing a reference for enzymatic preparation development and utilization.
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Affiliation(s)
- Chen Chen
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, China
| | - Xingfei Li
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, China
| | - Cheng Lu
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Bioengineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Xing Zhou
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Long Chen
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Chao Qiu
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Zhengyu Jin
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, China
| | - Jie Long
- The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, China.
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Gu X, Fu L, Wang Z, Cao Z, Zhao L, Seswita-Zilda D, Zhang A, Zhang Q, Li J. A Novel Bifunctional Alginate Lyase and Antioxidant Activity of the Enzymatic Hydrolysates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:4116-4126. [PMID: 38372665 DOI: 10.1021/acs.jafc.3c08638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Alginate lyase Aly448, a potential new member of the polysaccharide lyase (PL) 7 family, which was cloned and identified from the macroalgae-associated bacterial metagenomic library, showed bifunctionality. The molecular docking results revealed that Aly448 has two completely different binding sites for alginate (polyMG), poly-α-l-guluronic acid (polyG), and poly-β-d-mannuronic acid (polyM) substrates, respectively, which might be the molecular basis for the enzyme's bifunctionality. Truncational results confirmed that predicted key residues affected the bifunctionality of Aly448, but did not wholly explain. Besides, Aly448 presented excellent biochemical characteristics, such as higher thermal stability and pH tolerance. Degradation of polyMG, polyM, and polyG substrates by Aly448 produced tetrasaccharide (DP4), disaccharide (DP2), and galactose (DP1), which exhibited excellent antioxidant activity. These findings provide novel insights into the substrate recognition mechanism of bifunctional alginate lyases and pave a new path for the exploitation of natural antioxidant agents.
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Affiliation(s)
- Xiaoqian Gu
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Liping Fu
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Zhiyan Wang
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Zhe Cao
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Luying Zhao
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Dewi Seswita-Zilda
- Research Center for Deep Sea, Earth Sciences and Maritime Research Organization, National Research and Innovation Agency (BRIN), Jl. Pasir Putih Raya, Pademangan, North Jakarta City, Jakarta 14430, Indonesia
| | - Ao Zhang
- Chemical Engineering Institute, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Qian Zhang
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Jiang Li
- Key Lab of Ecological Environment Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
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Ochiai A. Discovery of new functions of food proteins and their structural development for multifunctional applications. Biosci Biotechnol Biochem 2023; 87:1102-1110. [PMID: 37480241 DOI: 10.1093/bbb/zbad098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 07/11/2023] [Indexed: 07/23/2023]
Abstract
Proteins and peptides derived from various food sources are used in a variety of applications, including functional foods, pharmaceuticals, and cosmetics. The three-dimensional structure of proteins provides useful insights into their functions and essential information for the creation of proteins with new functions. In this review, a series of functional conversion technologies based on protein structural information derived from foods traditionally consumed in Japan, such as natto (fermented soybeans) and rice, are introduced. For natto, we first identified 2 types of Bacillus subtilis-derived endolytic and exolytic enzymes with different modes of action on soybean cell wall polysaccharides and then focused on the technology used to create an endolytic enzyme from an exolytic enzyme. By applying this technology, a method for creating novel bioactive peptides from rice seed proteins was established. The modified peptides created could provide diverse options for the production of substances such as pharmaceuticals and cosmetic materials.
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Affiliation(s)
- Akihito Ochiai
- Department of Materials Science and Technology, Faculty of Engineering, Niigata University, Niigata, Japan
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
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Pandey S, Berger BW, Acharya R. Structural Analyses of Substrate-pH Activity Pairing Observed across Diverse Polysaccharide Lyases. Biochemistry 2023; 62:2775-2790. [PMID: 37620757 DOI: 10.1021/acs.biochem.3c00321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Anionic polysaccharides found in nature are functionally and structurally diverse, and so are the polysaccharide lyases (PLs) that catalyze their degradation. Atomic superposition of various PL folds according to their cleavable substrate structure confirms the occurrence of structural convergence at PL active sites. This suggests that various PL folds have emerged to cleave a particular class of anionic polysaccharide during the course of evolution. Whereas the structural and mechanistic similarity of PL active site has been highlighted in earlier studies, a detailed understanding regarding functional properties of this catalytic convergence remains an open question, especially the role of extrinsic factors such as pH in the context of substrate binding and catalysis. Our earlier structural and functional work on pH directed multisubstrate specificity of Smlt1473 inspired us to regroup PLs according to substrate type to analyze the pH dependence of their catalytic activity. Interestingly, we find that particular groups of substrates are cleaved in a particular pH range (acidic/neutral/basic) irrespective of PL fold, boosting the idea of functional convergence as well. On the basis of this observation, we set out to define structurally and computationally the key constituents of an active site among PL families. This study delineates the structural determinants of conserved "substrate-pH activity pairing" within and between PL families.
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Affiliation(s)
- Shubhant Pandey
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, 752050 Odisha, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094 Maharashtra, India
| | - Bryan W Berger
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Rudresh Acharya
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, 752050 Odisha, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094 Maharashtra, India
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Wang HY, Chen ZF, Zheng ZH, Lei HW, Cong HH, Zhou HX. A Novel Cold-Adapted and High-Alkaline Alginate Lyase with Potential for Alginate Oligosaccharides Preparation. Molecules 2023; 28:6190. [PMID: 37687019 PMCID: PMC10488352 DOI: 10.3390/molecules28176190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 09/10/2023] Open
Abstract
Alginate oligosaccharides (AOs) prepared through enzymatic reaction by diverse alginate lyases under relatively controllable and moderate conditions possess versatile biological activities. But widely used commercial alginate lyases are still rather rare due to their poor properties (e.g., lower activity, worse thermostability, ion tolerance, etc.). In this work, the alginate lyase Alyw208, derived from Vibrio sp. W2, was expressed in Yarrowia lipolytica of food grade and characterized in order to obtain an enzyme with excellent properties adapted to industrial requirements. Alyw208 classified into the polysaccharide lyase (PL) 7 family showed maximum activity at 35 °C and pH 10.0, indicating its cold-adapted and high-alkaline properties. Furthermore, Alyw208 preserved over 70% of the relative activity within the range of 10-55 °C, with a broader temperature range for the activity compared to other alginate-degrading enzymes with cold adaptation. Recombinant Alyw208 was significantly activated with 1.5 M NaCl to around 2.1 times relative activity. In addition, the endolytic Alyw208 was polyG-preferred, but identified as a bifunctional alginate lyase that could degrade both polyM and polyG effectively, releasing AOs with degrees of polymerization (DPs) of 2-6 and alginate monomers as the final products (that is, DPs 1-6). Alyw208 has been suggested with favorable properties to be a potent candidate for biotechnological and industrial applications.
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Affiliation(s)
- Hai-Ying Wang
- Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (H.-Y.W.); (Z.-F.C.); (Z.-H.Z.); (H.-W.L.)
| | - Zhi-Fang Chen
- Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (H.-Y.W.); (Z.-F.C.); (Z.-H.Z.); (H.-W.L.)
- Shandong Peanut Research Institute, Qingdao 266100, China
- College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China
| | - Zhi-Hong Zheng
- Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (H.-Y.W.); (Z.-F.C.); (Z.-H.Z.); (H.-W.L.)
- College of Food Science and Engineering, Dalian Ocean University, Dalian 116023, China
| | - Hui-Wen Lei
- Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (H.-Y.W.); (Z.-F.C.); (Z.-H.Z.); (H.-W.L.)
- College of Food Science and Engineering, Dalian Ocean University, Dalian 116023, China
| | - Hai-Hua Cong
- College of Food Science and Technology, Suzhou Polytechnic Institute of Agriculture, Suzhou 215008, China
| | - Hai-Xiang Zhou
- Shandong Peanut Research Institute, Qingdao 266100, China
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Li H, Huang X, Yao S, Zhang C, Hong X, Wu T, Jiang Z, Ni H, Zhu Y. Characterization of a bifunctional and endolytic alginate lyase from Microbulbifer sp. ALW1 and its application in alginate oligosaccharides production from Laminaria japonica. Protein Expr Purif 2022; 200:106171. [PMID: 36103937 DOI: 10.1016/j.pep.2022.106171] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 11/27/2022]
Abstract
The diverse biological activities of alginate oligosaccharides attracted extensive exploration of alginate lyases with various substrate specificity and enzymatic properties. In this study, an alginate lyase from Microbulbifer sp. ALW1, namely AlgL7, was phylogenetically classified into the polysaccharide lyase family 7 (PL7). The conserved amino acid residues Tyr606 and His499 in AlgL7 were predicted to act as the general acid/base catalysts. The enzyme was enzymatically characterized after heterologous expression and purification in E. coli. AlgL7 displayed optimal activity at 40 °C and pH 7.0. It had good stability at temperature below 35 °C and within a pH range of 5.0-10.0. AlgL7 exhibited good stability against the reducing reagent β-ME and the surfactants of Tween-20 and Triton X-100. The degradation profiles of alginate indicated AlgL7 was a bifunctional endolytic alginate lyase generating alginate oligosaccharides with the degrees of polymerization 2-4. The degradation products of sodium alginate exhibited stronger antioxidant activities than the untreated polysaccharide. In addition, AlgL7 could directly digest Laminaria japonica to produce alginate oligosaccharides. These characteristics of AlgL7 offer a great potential of its application in high-value utilization of brown algae resources.
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Affiliation(s)
- Hebin Li
- Department of Pharmacy, Xiamen Medical College, Xiamen, 361008, China
| | - Xiaoyi Huang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, China
| | - Shuxiang Yao
- Xiamen Institute of Software Technology, Xiamen, 361024, China
| | - Chenghao Zhang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, China
| | - Xuan Hong
- Department of Pharmacy, Xiamen Medical College, Xiamen, 361008, China
| | - Ting Wu
- Department of Pharmacy, Xiamen Medical College, Xiamen, 361008, China
| | - Zedong Jiang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, China
| | - Hui Ni
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, China
| | - Yanbing Zhu
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, China.
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7
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Dobruchowska JM, Bjornsdottir B, Fridjonsson OH, Altenbuchner J, Watzlawick H, Gerwig GJ, Dijkhuizen L, Kamerling JP, Hreggvidsson GO. Enzymatic depolymerization of alginate by two novel thermostable alginate lyases from Rhodothermus marinus. FRONTIERS IN PLANT SCIENCE 2022; 13:981602. [PMID: 36204061 PMCID: PMC9530828 DOI: 10.3389/fpls.2022.981602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/17/2022] [Indexed: 06/16/2023]
Abstract
Alginate (alginic acid) is a linear polysaccharide, wherein (1→4)-linked β-D-mannuronic acid and its C5 epimer, α-L-guluronic acid, are arranged in varying sequences. Alginate lyases catalyze the depolymerization of alginate, thereby cleaving the (1→4) glycosidic linkages between the monomers by a β-elimination mechanism, to yield unsaturated 4-deoxy-L-erythro-hex-4-enopyranosyluronic acid (Δ) at the non-reducing end of resulting oligosaccharides (α-L-erythro configuration) or, depending on the enzyme, the unsaturated monosaccharide itself. In solution, the released free unsaturated monomer product is further hydrated in a spontaneous (keto-enol tautomerization) process to form two cyclic stereoisomers. In this study, two alginate lyase genes, designated alyRm3 and alyRm4, from the marine thermophilic bacterium Rhodothermus marinus (strain MAT378), were cloned and expressed in Escherichia coli. The recombinant enzymes were characterized, and their substrate specificity and product structures determined. AlyRm3 (PL39) and AlyRm4 (PL17) are among the most thermophilic and thermostable alginate lyases described to date with temperature optimum of activity at ∼75 and 81°C, respectively. The pH optimum of activity of AlyRm3 is ∼5.5 and AlyRm4 at pH 6.5. Detailed NMR analysis of the incubation products demonstrated that AlyRm3 is an endolytic lyase, while AlyRm4 is an exolytic lyase, cleaving monomers from the non-reducing end of oligo/poly-alginates.
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Affiliation(s)
- Justyna M. Dobruchowska
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, Netherlands
| | | | | | - Josef Altenbuchner
- Institute for Industrial Genetics, University of Stuttgart, Stuttgart, Germany
| | | | - Gerrit J. Gerwig
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, Netherlands
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, Netherlands
| | - Johannis P. Kamerling
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, Netherlands
| | - Gudmundur O. Hreggvidsson
- Matís Ltd., Reykjavík, Iceland
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
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Cao S, Li Q, Xu Y, Tang T, Ning L, Zhu B. Evolving strategies for marine enzyme engineering: recent advances on the molecular modification of alginate lyase. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:106-116. [PMID: 37073348 PMCID: PMC10077200 DOI: 10.1007/s42995-021-00122-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/14/2021] [Indexed: 05/03/2023]
Abstract
Alginate, an acidic polysaccharide, is formed by β-d-mannuronate (M) and α-l-guluronate (G). As a type of polysaccharide lyase, alginate lyase can efficiently degrade alginate into alginate oligosaccharides, having potential applications in the food, medicine, and agriculture fields. However, the application of alginate lyase has been limited due to its low catalytic efficiency and poor temperature stability. In recent years, various structural features of alginate lyase have been determined, resulting in modification strategies that can increase the applicability of alginate lyase, making it important to summarize and discuss the current evidence. In this review, we summarized the structural features and catalytic mechanisms of alginate lyase. Molecular modification strategies, such as rational design, directed evolution, conserved domain recombination, and non-catalytic domain truncation, are also described in detail. Lastly, the application of alginate lyase is discussed. This comprehensive summary can inform future applications of alginate lyases.
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Affiliation(s)
- Shengsheng Cao
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816 China
| | - Qian Li
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816 China
| | - Yinxiao Xu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816 China
| | - Tiancheng Tang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816 China
| | - Limin Ning
- School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Benwei Zhu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816 China
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Abstract
Microbes are hardly seen as planktonic species and are most commonly found as biofilm communities in cases of chronic infections. Biofilms are regarded as a biological condition, where a large group of microorganisms gets adhered to a biotic or abiotic surface. In this context, Pseudomonas aeruginosa, a Gram-negative nosocomial pathogen is the main causative organism responsible for life-threatening and persistent infections in individuals affected with cystic fibrosis and other lung ailments. The bacteria can form a strong biofilm structure when it adheres to a surface suitable for the development of a biofilm matrix. These bacterial biofilms pose higher natural resistance to conventional antibiotic therapy due to their multiple tolerance mechanisms. This prevailing condition has led to an increasing rate of treatment failures associated with P. aeruginosa biofilm infections. A better understanding of the effect of a diverse group of antibiotics on established biofilms would be necessary to avoid inappropriate treatment strategies. Hence, the search for other alternative strategies as effective biofilm treatment options has become a growing area of research. The current review aims to give an overview of the mechanisms governing biofilm formation and the different strategies employed so far in the control of biofilm infections caused by P. aeruginosa. Moreover, this review can also help researchers to search for new antibiofilm agents to tackle the effect of biofilm infections that are currently imprudent to conventional antibiotics.
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Violot S, Galisson F, Carrique L, Jugnarain V, Conchou L, Robert X, Thureau A, Helbert W, Aghajari N, Ballut L. Exploring molecular determinants of polysaccharide Lyase family 6-1 enzyme activity. Glycobiology 2021; 31:1557-1570. [PMID: 34245266 DOI: 10.1093/glycob/cwab073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/24/2021] [Accepted: 07/07/2021] [Indexed: 11/14/2022] Open
Abstract
The Polysaccharide Lyase Family 6 (PL6) represents one of the 41 polysaccharide lyase families classified in the CAZy database with the vast majority of its members being alginate lyases grouped into three subfamilies, PL6_1-3. To decipher the mode of recognition and action of the enzymes belonging to subfamily PL6_1, we solved the crystal structures of Pedsa0632, Patl3640, Pedsa3628 and Pedsa3807, which all show different substrate specificities and mode of action (endo-/exo-lyase). Thorough exploration of the structures of Pedsa0632 and Patl3640 in complex with their substrates as well as docking experiments confirm that the conserved residues in subsites -1 to +3 of the catalytic site form a common platform which can accommodate various types of alginate in a very similar manner but with a series of original adaptations bringing them their specificities of action. From comparative studies with existing structures of PL6_1 alginate lyases, we observe that in the right-handed parallel β-helix fold shared by all these enzymes, the substrate binding site harbors the same overall conserved structures and organization. Despite this apparent similarity, it appears that members of the PL6_1 subfamily specifically accommodate and catalyze the degradation of different alginates suggesting that this common platform is actually a highly adaptable and specific tool.
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Affiliation(s)
- Sébastien Violot
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Frédéric Galisson
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Loïc Carrique
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Vinesh Jugnarain
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Léa Conchou
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Xavier Robert
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | | | - William Helbert
- Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Grenoble Alpes, CNRS, 38000 Grenoble, France
| | - Nushin Aghajari
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - Lionel Ballut
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
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11
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Dharani SR, Srinivasan R, Sarath R, Ramya M. Recent progress on engineering microbial alginate lyases towards their versatile role in biotechnological applications. Folia Microbiol (Praha) 2020; 65:937-954. [DOI: 10.1007/s12223-020-00802-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/16/2020] [Indexed: 11/30/2022]
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12
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Zhu B, Li K, Wang W, Ning L, Tan H, Zhao X, Yin H. Preparation of trisaccharides from alginate by a novel alginate lyase Alg7A from marine bacterium Vibrio sp. W13. Int J Biol Macromol 2019; 139:879-885. [DOI: 10.1016/j.ijbiomac.2019.08.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/24/2019] [Accepted: 08/01/2019] [Indexed: 01/18/2023]
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13
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Liu J, Yang S, Li X, Yan Q, Reaney MJT, Jiang Z. Alginate Oligosaccharides: Production, Biological Activities, and Potential Applications. Compr Rev Food Sci Food Saf 2019; 18:1859-1881. [DOI: 10.1111/1541-4337.12494] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/09/2019] [Accepted: 07/29/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Jun Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural Univ. Beijing 100083 China
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthBeijing Technology and Business Univ. Beijing 100048 China
| | - Shaoqing Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural Univ. Beijing 100083 China
| | - Xiuting Li
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthBeijing Technology and Business Univ. Beijing 100048 China
| | - Qiaojuan Yan
- Bioresource Utilization LaboratoryCollege of EngineeringChina Agricultural Univ. Beijing 100083 China
| | - Martin J. T. Reaney
- Dept. of Plant SciencesUniv. of Saskatchewan Saskatoon SK S7N 5A8 Canada
- Guangdong Saskatchewan Oilseed Joint Laboratory (GUSTO)Dept. of Food Science and EngineeringJinan Univ. Guangzhou 510632 China
| | - Zhengqiang Jiang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural Univ. Beijing 100083 China
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14
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Wong S, Eckersley EL, Berger B, Klauda JB. Probing the pH Effects on Sugar Binding to a Polysaccharide Lyase. J Phys Chem B 2019; 123:7123-7136. [DOI: 10.1021/acs.jpcb.9b04672] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Evan L. Eckersley
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Bryan Berger
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904, United States
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15
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Wang D, Aarstad OA, Li J, McKee LS, Sætrom GI, Vyas A, Srivastava V, Aachmann FL, Bulone V, Hsieh YS. Preparation of 4-Deoxy-L-erythro-5-hexoseulose Uronic Acid (DEH) and Guluronic Acid Rich Alginate Using a Unique exo-Alginate Lyase from Thalassotalea crassostreae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:1435-1443. [PMID: 29363310 DOI: 10.1021/acs.jafc.7b05751] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Marine multicellular algae are considered promising crops for the production of sustainable biofuels and commodity chemicals. However, their commercial exploitation is currently limited by a lack of appropriate and efficient enzymes for converting alginate into metabolizable building blocks, such as 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEH). Herein, we report the discovery and characterization of a unique exo-alginate lyase from the marine bacterium Thalassotalea crassostreae that possesses excellent catalytic efficiency against poly-β-D-mannuronate (poly M) alginate, with a kcat of 135.8 s-1, and a 5-fold lower kcat of 25 s-1 against poly-α-L-guluronate (poly G alginate). We propose that this preference for poly M is due to a structural feature of the protein's active site. The mode of action and specificity of this enzyme has made it possible to design an effective and environmentally friendly process for the production of DEH and low molecular weight guluronate-enriched alginate.
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Affiliation(s)
- Damao Wang
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
- Wallenberg Wood Science Centre, Royal Institute of Technology (KTH) , SE-100 44, Stockholm, Sweden
| | - Olav A Aarstad
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology , N-7491 Trondheim, Norway
| | - Jing Li
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
| | - Lauren S McKee
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
- Wallenberg Wood Science Centre, Royal Institute of Technology (KTH) , SE-100 44, Stockholm, Sweden
| | - Gerd Inger Sætrom
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology , N-7491 Trondheim, Norway
| | - Anisha Vyas
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
| | - Vaibhav Srivastava
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
| | - Finn L Aachmann
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology , N-7491 Trondheim, Norway
| | - Vincent Bulone
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
- Wallenberg Wood Science Centre, Royal Institute of Technology (KTH) , SE-100 44, Stockholm, Sweden
| | - Yves Sy Hsieh
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center , Stockholm, SE-106 91, Sweden
- Wallenberg Wood Science Centre, Royal Institute of Technology (KTH) , SE-100 44, Stockholm, Sweden
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16
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Xu F, Wang P, Zhang YZ, Chen XL. Diversity of Three-Dimensional Structures and Catalytic Mechanisms of Alginate Lyases. Appl Environ Microbiol 2018; 84:e02040-17. [PMID: 29150496 PMCID: PMC5772247 DOI: 10.1128/aem.02040-17] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alginate is a linear polysaccharide produced mainly by brown algae in marine environments. Alginate consists of a linear block copolymer made up of two monomeric units, β-d-mannuronate (M) and its C-5 epimer α-l-guluronate (G). Alginate lyases are polysaccharide lyases (PL) that degrade alginate via a β-elimination reaction. These enzymes play an important role in marine carbon recycling and also have widespread industrial applications. So far, more than 1,774 alginate lyase sequences have been identified and are distributed into 7 PL families. In this review, the folds, conformational changes during catalysis, and catalytic mechanisms of alginate lyases are described. Thus far, structures for 15 alginate lyases have been solved and are divided into 3 fold classes: the β-jelly roll class (PL7, -14, and -18), the (α/α)n toroid class (PL5, -15, and -17), and the β-helix fold (PL6). These enzymes adopt two different mechanisms for catalysis, and three kinds of conformational changes occur during this process. Moreover, common features in the structures, conformational changes, and catalytic mechanisms are summarized, providing a comprehensive understanding on alginate lyases.
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Affiliation(s)
- Fei Xu
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Peng Wang
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Yu-Zhong Zhang
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xiu-Lan Chen
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
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17
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Richardson JS, Videau LL, Williams CJ, Richardson DC. Broad Analysis of Vicinal Disulfides: Occurrences, Conformations with Cis or with Trans Peptides, and Functional Roles Including Sugar Binding. J Mol Biol 2017; 429:1321-1335. [PMID: 28336403 DOI: 10.1016/j.jmb.2017.03.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/12/2017] [Accepted: 03/13/2017] [Indexed: 10/19/2022]
Abstract
Vicinal disulfides between sequence-adjacent cysteine residues are very rare and rather startling structural features which play a variety of functional roles. Typically discussed as an isolated curiosity, they have never received a general treatment covering both cis and trans forms. Enabled by the growing database of high-resolution structures, required deposition of diffraction data, and improved methods for discriminating reliable from dubious cases, we identify and describe distinct protein families with reliably genuine examples of cis or trans vicinal disulfides and discuss their conformations, conservation, and functions. No cis-trans interconversions and only one case of catalytic redox function are seen. Some vicinal disulfides are essential to large, functionally coupled motions, whereas most form the centers of tightly packed internal regions. Their most widespread biological role is providing a rigid hydrophobic contact surface under the undecorated side of a sugar or multiring ligand, contributing an important aspect of binding specificity.
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Affiliation(s)
- Jane S Richardson
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA.
| | - Lizbeth L Videau
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA
| | | | - David C Richardson
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA
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18
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Xu F, Dong F, Wang P, Cao HY, Li CY, Li PY, Pang XH, Zhang YZ, Chen XL. Novel Molecular Insights into the Catalytic Mechanism of Marine Bacterial Alginate Lyase AlyGC from Polysaccharide Lyase Family 6. J Biol Chem 2017; 292:4457-4468. [PMID: 28154171 DOI: 10.1074/jbc.m116.766030] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/15/2017] [Indexed: 01/27/2023] Open
Abstract
Alginate lyases that degrade alginate via a β-elimination reaction fall into seven polysaccharide lyase (PL) families. Although the structures and catalytic mechanisms of alginate lyases in the other PL families have been clarified, those in family PL6 have yet to be revealed. Here, the crystal structure of AlyGC, a PL6 alginate lyase from marine bacterium Glaciecola chathamensis S18K6T, was solved, and its catalytic mechanism was illustrated. AlyGC is a homodimeric enzyme and adopts a structure distinct from other alginate lyases. Each monomer contains a catalytic N-terminal domain and a functionally unknown C-terminal domain. A combined structural and mutational analysis using the structures of AlyGC and of an inactive mutant R241A in complex with an alginate tetrasaccharide indicates that conformational changes occur in AlyGC when a substrate is bound and that the two active centers in AlyGC may not bind substrates simultaneously. The C-terminal domain is shown to be essential for the dimerization and the catalytic activity of AlyGC. Residues Tyr130, Arg187, His242, Arg265, and Tyr304 in the active center are also important for the activity of AlyGC. In catalysis, Lys220 and Arg241 function as the Brønsted base and acid, respectively, and a Ca2+ in the active center neutralizes the negative charge of the C5 carboxyl group of the substrate. Finally, based on our data, we propose a metal ion-assisted catalytic mechanism of AlyGC for alginate cleavage with a state change mode, which provides a better understanding for polysaccharide lyases and alginate degradation.
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Affiliation(s)
- Fei Xu
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Fang Dong
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Peng Wang
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Hai-Yan Cao
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Chun-Yang Li
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Ping-Yi Li
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Xiu-Hua Pang
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
| | - Yu-Zhong Zhang
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and.,the Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China
| | - Xiu-Lan Chen
- From the State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100 and
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19
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Dong S, Wei TD, Chen XL, Li CY, Wang P, Xie BB, Qin QL, Zhang XY, Pang XH, Zhou BC, Zhang YZ. Molecular insight into the role of the N-terminal extension in the maturation, substrate recognition, and catalysis of a bacterial alginate lyase from polysaccharide lyase family 18. J Biol Chem 2014; 289:29558-69. [PMID: 25210041 DOI: 10.1074/jbc.m114.584573] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacterial alginate lyases, which are members of several polysaccharide lyase (PL) families, have important biological roles and biotechnological applications. The mechanisms for maturation, substrate recognition, and catalysis of PL18 alginate lyases are still largely unknown. A PL18 alginate lyase, aly-SJ02, from Pseudoalteromonas sp. 0524 displays a β-jelly roll scaffold. Structural and biochemical analyses indicated that the N-terminal extension in the aly-SJ02 precursor may act as an intramolecular chaperone to mediate the correct folding of the catalytic domain. Molecular dynamics simulations and mutational assays suggested that the lid loops over the aly-SJ02 active center serve as a gate for substrate entry. Molecular docking and site-directed mutations revealed that certain conserved residues at the active center, especially those at subsites +1 and +2, are crucial for substrate recognition. Tyr(353) may function as both a catalytic base and acid. Based on our results, a model for the catalysis of aly-SJ02 in alginate depolymerization is proposed. Moreover, although bacterial alginate lyases from families PL5, 7, 15, and 18 adopt distinct scaffolds, they share the same conformation of catalytic residues, reflecting their convergent evolution. Our results provide the foremost insight into the mechanisms of maturation, substrate recognition, and catalysis of a PL18 alginate lyase.
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Affiliation(s)
- Sheng Dong
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Tian-Di Wei
- From the State Key Laboratory of Microbial Technology and
| | - Xiu-Lan Chen
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Chun-Yang Li
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Peng Wang
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Bin-Bin Xie
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Qi-Long Qin
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Xi-Ying Zhang
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Xiu-Hua Pang
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Bai-Cheng Zhou
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Yu-Zhong Zhang
- From the State Key Laboratory of Microbial Technology and the Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
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20
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MacDonald LC, Berger BW. Insight into the role of substrate-binding residues in conferring substrate specificity for the multifunctional polysaccharide lyase Smlt1473. J Biol Chem 2014; 289:18022-32. [PMID: 24808176 DOI: 10.1074/jbc.m114.571299] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Anionic polysaccharides are of growing interest in the biotechnology industry due to their potential pharmaceutical applications in drug delivery and wound treatment. Chemical composition and polymer length strongly influence the physical and biological properties of the polysaccharide and thus its potential industrial and medical applications. One promising approach to determining monomer composition and controlling the degree of polymerization involves the use of polysaccharide lyases, which catalyze the depolymerization of anionic polysaccharides via a β-elimination mechanism. Utilization of these enzymes for the production of custom-made oligosaccharides requires a high degree of control over substrate specificity. Previously, we characterized a polysaccharide lyase (Smlt1473) from Stenotrophomonas maltophilia k279a, which exhibited significant activity against hyaluronan (HA), poly-β-d-glucuronic acid (poly-GlcUA), and poly-β-d-mannuronic acid (poly-ManA) in a pH-regulated manner. Here, we utilize a sequence structure guided approach based on a homology model of Smlt1473 to identify nine putative substrate-binding residues and examine their effect on substrate specificity via site-directed mutagenesis. Interestingly, single point mutations H221F and R312L resulted in increased activity and specificity toward poly-ManA and poly-GlcUA, respectively. Furthermore, a W171A mutant nearly eliminated HA activity, while increasing poly-ManA and poly-GlcUA activity by at least 35%. The effect of these mutations was analyzed by comparison with the high resolution structure of Sphingomonas sp. A1-III alginate lyase in complex with poly-ManA tetrasaccharide and by taking into account the structural differences between HA, poly-GlcUA, and poly-ManA. Overall, our results demonstrate that even minor changes in active site architecture have a significant effect on the substrate specificity of Smlt1473, whose structural plasticity could be applied to the design of highly active and specific polysaccharide lyases.
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Affiliation(s)
| | - Bryan W Berger
- From the Program in Bioengineering and Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
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21
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MacDonald LC, Berger BW. A polysaccharide lyase from Stenotrophomonas maltophilia with a unique, pH-regulated substrate specificity. J Biol Chem 2013; 289:312-25. [PMID: 24257754 DOI: 10.1074/jbc.m113.489195] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polysaccharide lyases (PLs) catalyze the depolymerization of anionic polysaccharides via a β-elimination mechanism. PLs also play important roles in microbial pathogenesis, participating in bacterial invasion and toxin spread into the host tissue via degradation of the host extracellular matrix, or in microbial biofilm formation often associated with enhanced drug resistance. Stenotrophomonas maltophilia is a Gram-negative bacterium that is among the emerging multidrug-resistant organisms associated with chronic lung infections as well as with cystic fibrosis patients. A putative alginate lyase (Smlt1473) from S. maltophilia was heterologously expressed in Escherichia coli, purified in a one-step fashion via affinity chromatography, and activity as well as specificity determined for a range of polysaccharides. Interestingly, Smlt1473 catalyzed the degradation of not only alginate, but poly-β-D-glucuronic acid and hyaluronic acid as well. Furthermore, the pH optimum for enzymatic activity is substrate-dependent, with optimal hyaluronic acid degradation at pH 5, poly-β-D-glucuronic acid degradation at pH 7, and alginate degradation at pH 9. Analysis of the degradation products revealed that each substrate was cleaved endolytically into oligomers comprised predominantly of even numbers of sugar groups, with lower accumulation of trimers and pentamers. Collectively, these results imply that Smlt1473 is a multifunctional PL that exhibits broad substrate specificity, but utilizes pH as a mechanism to achieve selectivity.
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22
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Mikami B, Ban M, Suzuki S, Yoon HJ, Miyake O, Yamasaki M, Ogura K, Maruyama Y, Hashimoto W, Murata K. Induced-fit motion of a lid loop involved in catalysis in alginate lyase A1-III. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:1207-16. [PMID: 22948922 DOI: 10.1107/s090744491202495x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 05/31/2012] [Indexed: 11/11/2022]
Abstract
The structures of two mutants (H192A and Y246F) of a mannuronate-specific alginate lyase, A1-III, from Sphingomonas species A1 complexed with a tetrasaccharide substrate [4-deoxy-L-erythro-hex-4-ene-pyranosyluronate-(mannuronate)(2)-mannuronic acid] were determined by X-ray crystallography at around 2.2 Å resolution together with the apo form of the H192A mutant. The final models of the complex forms, which comprised two monomers (of 353 amino-acid residues each), 268-287 water molecules and two tetrasaccharide substrates, had R factors of around 0.17. A large conformational change occurred in the position of the lid loop (residues 64-85) in holo H192A and Y246F compared with that in apo H192A. The lid loop migrated about 14 Å from an open form to a closed form to interact with the bound tetrasaccharide and a catalytic residue. The tetrasaccharide was bound in the active cleft at subsites -3 to +1 as a substrate form in which the glycosidic linkage to be cleaved existed between subsites -1 and +1. In particular, the O(η) atom of Tyr68 in the closed lid loop forms a hydrogen bond to the side chain of a presumed catalytic residue, O(η) of Tyr246, which acts both as an acid and a base catalyst in a syn mechanism.
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Affiliation(s)
- Bunzo Mikami
- Department of Applied Life Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan.
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23
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Wolfram F, Arora K, Robinson H, Neculai AM, Yip P, Howell PL. Expression, purification, crystallization and preliminary X-ray analysis of Pseudomonas aeruginosa AlgL. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:584-7. [PMID: 22691793 PMCID: PMC3374518 DOI: 10.1107/s1744309112012808] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/23/2012] [Indexed: 11/10/2022]
Abstract
The periplasmic alginate lyase AlgL is essential for the synthesis and export of the exopolysaccharide alginate in Pseudomonas sp. and also plays a role in its depolymerization. P. aeruginosa PAO1 AlgL has been overexpressed and purified and diffraction-quality crystals were grown using the hanging-drop vapour-diffusion method. The crystals grew as thin plates, with unit-cell parameters a = 56.4, b = 59.6, c = 102.1 Å, α = β = γ = 90°. The AlgL crystals exhibited the symmetry of space group P2(1)2(1)2(1) and diffracted to a minimum d-spacing of 1.64 Å. Based on the Matthews coefficient (V(M) = 2.20 Å(3) Da(-1)), one molecule is estimated to be present in the asymmetric unit.
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Affiliation(s)
- Francis Wolfram
- Program in Molecular Structure and Function, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Kritica Arora
- Program in Molecular Structure and Function, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Howard Robinson
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA
| | - Ana Mirela Neculai
- Program in Molecular Structure and Function, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Patrick Yip
- Program in Molecular Structure and Function, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - P. Lynne Howell
- Program in Molecular Structure and Function, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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24
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Lundqvist LC, Jam M, Barbeyron T, Czjzek M, Sandström C. Substrate specificity of the recombinant alginate lyase from the marine bacteria Pseudomonas alginovora. Carbohydr Res 2012; 352:44-50. [DOI: 10.1016/j.carres.2012.02.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/07/2012] [Accepted: 02/10/2012] [Indexed: 11/17/2022]
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26
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Franklin MJ, Nivens DE, Weadge JT, Howell PL. Biosynthesis of the Pseudomonas aeruginosa Extracellular Polysaccharides, Alginate, Pel, and Psl. Front Microbiol 2011; 2:167. [PMID: 21991261 PMCID: PMC3159412 DOI: 10.3389/fmicb.2011.00167] [Citation(s) in RCA: 327] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 07/19/2011] [Indexed: 12/30/2022] Open
Abstract
Pseudomonas aeruginosa thrives in many aqueous environments and is an opportunistic pathogen that can cause both acute and chronic infections. Environmental conditions and host defenses cause differing stresses on the bacteria, and to survive in vastly different environments, P. aeruginosa must be able to adapt to its surroundings. One strategy for bacterial adaptation is to self-encapsulate with matrix material, primarily composed of secreted extracellular polysaccharides. P. aeruginosa has the genetic capacity to produce at least three secreted polysaccharides; alginate, Psl, and Pel. These polysaccharides differ in chemical structure and in their biosynthetic mechanisms. Since alginate is often associated with chronic pulmonary infections, its biosynthetic pathway is the best characterized. However, alginate is only produced by a subset of P. aeruginosa strains. Most environmental and other clinical isolates secrete either Pel or Psl. Little information is available on the biosynthesis of these polysaccharides. Here, we review the literature on the alginate biosynthetic pathway, with emphasis on recent findings describing the structure of alginate biosynthetic proteins. This information combined with the characterization of the domain architecture of proteins encoded on the Psl and Pel operons allowed us to make predictive models for the biosynthesis of these two polysaccharides. The results indicate that alginate and Pel share certain features, including some biosynthetic proteins with structurally or functionally similar properties. In contrast, Psl biosynthesis resembles the EPS/CPS capsular biosynthesis pathway of Escherichia coli, where the Psl pentameric subunits are assembled in association with an isoprenoid lipid carrier. These models and the environmental cues that cause the cells to produce predominantly one polysaccharide over the others are subjects of current investigation.
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27
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Hashimoto W, Kawai S, Murata K. Bacterial supersystem for alginate import/metabolism and its environmental and bioenergy applications. Bioeng Bugs 2009; 1:97-109. [PMID: 21326935 DOI: 10.4161/bbug.1.2.10322] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 10/13/2009] [Accepted: 10/14/2009] [Indexed: 11/19/2022] Open
Abstract
Distinct from most alginate-assimilating bacteria that secrete polysaccharide lyases extracellularly, a gram-negative bacterium, Sphingomonas sp. A1 (strain A1), can directly incorporate alginate into its cytoplasm, without degradation, through a "superchannel" consisting of a mouth-like pit on the cell surface, periplasmic binding proteins, and a cytoplasmic membrane-bound ATP-binding cassette transporter. Flagellin homologues function as cell surface alginate receptors essential for expressing the superchannel. Cytoplasmic alginate lyases with different substrate specificities and action modes degrade the polysaccharide to its constituent monosaccharides. The resultant monosaccharides, α-keto acids, are converted to a reduced form by NADPH-dependent reductase, and are finally metabolized in the TCA cycle. Transplantation of the strain A1 superchannel to xenobiotic-degrading sphingomonads enhances bioremediation through the propagation of bacteria with an elevated transport activity. Furthermore, strain A1 cells transformed with Zymomonas mobilis genes for pyruvate decarboxylase and alcohol dehydrogenase II produce considerable amounts of biofuel ethanol from alginate when grown statically.
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Affiliation(s)
- Wataru Hashimoto
- Laboratory of Basic and Applied Molecular Biotechnology,; Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
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Catalytically important amino-acid residues of abalone alginate lyase HdAly assessed by site-directed mutagenesis. Enzyme Microb Technol 2008. [DOI: 10.1016/j.enzmictec.2008.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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30
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Michaud P, Da Costa A, Courtois B, Courtois J. Polysaccharide Lyases: Recent Developments as Biotechnological Tools. Crit Rev Biotechnol 2008; 23:233-66. [PMID: 15224891 DOI: 10.1080/07388550390447043] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Polysaccharide lyases, which are polysaccharide cleavage enzymes, act mainly on anionic polysaccharides. Produced by prokaryote and eukaryote organisms, these enzymes degrade (1,4) glycosidic bond by a beta elimination mechanism and have unsaturated oligosaccharides as major products. New polysaccharides are cleaved only by their specific polysaccharide lyases. From anionic polysaccharides controlled degradations, various biotechnological applications were investigated. This review catalogues the degradation of bacterial, plant and animal polysaccharides (neutral and anionic) by this family of carbohydrate acting enzymes.
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Affiliation(s)
- P Michaud
- Laboratoire des Glucides--LPMV, IUT/Génie Biologique, Université de Picardie Jules Verne, Avenue des Facultés, Le Bailly, 80025 Amiens Cedex, France.
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31
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Ogura K, Yamasaki M, Mikami B, Hashimoto W, Murata K. Substrate recognition by family 7 alginate lyase from Sphingomonas sp. A1. J Mol Biol 2008; 380:373-85. [DOI: 10.1016/j.jmb.2008.05.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 05/02/2008] [Accepted: 05/07/2008] [Indexed: 11/24/2022]
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32
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Rozeboom HJ, Bjerkan TM, Kalk KH, Ertesvåg H, Holtan S, Aachmann FL, Valla S, Dijkstra BW. Structural and mutational characterization of the catalytic A-module of the mannuronan C-5-epimerase AlgE4 from Azotobacter vinelandii. J Biol Chem 2008; 283:23819-28. [PMID: 18574239 DOI: 10.1074/jbc.m804119200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alginate is a family of linear copolymers of (1-->4)-linked beta-d-mannuronic acid and its C-5 epimer alpha-l-guluronic acid. The polymer is first produced as polymannuronic acid and the guluronic acid residues are then introduced at the polymer level by mannuronan C-5-epimerases. The structure of the catalytic A-module of the Azotobacter vinelandii mannuronan C-5-epimerase AlgE4 has been determined by x-ray crystallography at 2.1-A resolution. AlgE4A folds into a right-handed parallel beta-helix structure originally found in pectate lyase C and subsequently in several polysaccharide lyases and hydrolases. The beta-helix is composed of four parallel beta-sheets, comprising 12 complete turns, and has an amphipathic alpha-helix near the N terminus. The catalytic site is positioned in a positively charged cleft formed by loops extending from the surface encompassing Asp(152), an amino acid previously shown to be important for the reaction. Site-directed mutagenesis further implicates Tyr(149), His(154), and Asp(178) as being essential for activity. Tyr(149) probably acts as the proton acceptor, whereas His(154) is the proton donor in the epimerization reaction.
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Affiliation(s)
- Henriëtte J Rozeboom
- Laboratory of Biophysical Chemistry, GBB, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
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33
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Crystal Structure of YihS in Complex with d-Mannose: Structural Annotation of Escherichia coli and Salmonella enterica yihS-encoded Proteins to an Aldose–Ketose Isomerase. J Mol Biol 2008; 377:1443-59. [DOI: 10.1016/j.jmb.2008.01.090] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 01/18/2008] [Accepted: 01/22/2008] [Indexed: 11/20/2022]
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34
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Shaya D, Hahn BS, Bjerkan TM, Kim WS, Park NY, Sim JS, Kim YS, Cygler M. Composite active site of chondroitin lyase ABC accepting both epimers of uronic acid. Glycobiology 2008; 18:270-7. [PMID: 18227125 DOI: 10.1093/glycob/cwn002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Enzymes have evolved as catalysts with high degrees of stereospecificity. When both enantiomers are biologically important, enzymes with two different folds usually catalyze reactions with the individual enantiomers. In rare cases a single enzyme can process both enantiomers efficiently, but no molecular basis for such catalysis has been established. The family of bacterial chondroitin lyases ABC comprises such enzymes. They can degrade both chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans at the nonreducing end of either glucuronic acid (CS) or its epimer iduronic acid (DS) by a beta-elimination mechanism, which commences with the removal of the C-5 proton from the uronic acid. Two other structural folds evolved to perform these reactions in an epimer-specific fashion: (alpha/alpha)(5) for CS (chondroitin lyases AC) and beta-helix for DS (chondroitin lyases B); their catalytic mechanisms have been established at the molecular level. The structure of chondroitinase ABC from Proteus vulgaris showed surprising similarity to chondroitinase AC, including the presence of a Tyr-His-Glu-Arg catalytic tetrad, which provided a possible mechanism for CS degradation but not for DS degradation. We determined the structure of a distantly related Bacteroides thetaiotaomicron chondroitinase ABC to identify additional structurally conserved residues potentially involved in catalysis. We found a conserved cluster located approximately 12 A from the catalytic tetrad. We demonstrate that a histidine in this cluster is essential for catalysis of DS but not CS. The enzyme utilizes a single substrate-binding site while having two partially overlapping active sites catalyzing the respective reactions. The spatial separation of the two sets of residues suggests a substrate-induced conformational change that brings all catalytically essential residues close together.
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Affiliation(s)
- D Shaya
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
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35
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Ochiai A, Itoh T, Maruyama Y, Kawamata A, Mikami B, Hashimoto W, Murata K. A novel structural fold in polysaccharide lyases: Bacillus subtilis family 11 rhamnogalacturonan lyase YesW with an eight-bladed beta-propeller. J Biol Chem 2007; 282:37134-45. [PMID: 17947240 DOI: 10.1074/jbc.m704663200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rhamnogalacturonan (RG) lyase produced by plant pathogenic and saprophytic microbes plays an important role in degrading plant cell walls. An extracellular RG lyase YesW from saprophytic Bacillus subtilis is a member of polysaccharide lyase family 11 and cleaves glycoside bonds in polygalacturonan as well as RG type-I through a beta-elimination reaction. Crystal structures of YesW and its complex with galacturonan disaccharide, a reaction product analogue, were determined at 1.4 and 2.5 A resolutions with final R-factors of 16.4% and 16.6%, respectively. The enzyme is composed of an eight-bladed beta-propeller with a deep cleft in the center as a basic scaffold, and its structural fold has not been seen in polysaccharide lyases analyzed thus far. Structural analysis of the disaccharide-bound YesW and a site-directed mutagenesis study suggested that Arg-452 and Lys-535 stabilize the carboxyl group of the acidic polysaccharide molecule and Tyr-595 makes a stack interaction with the sugar pyranose ring. In addition to amino acid residues binding to the disaccharide, one calcium ion, which is coordinated by Asp-401, Glu-422, His-363, and His-399, may mediate the enzyme activity. This is, to our knowledge, the first report of a new structural category with a beta-propeller fold in polysaccharide lyases and provides structural insights into substrate binding by RG lyase.
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Affiliation(s)
- Akihito Ochiai
- Laboratory of Basic and Applied Molecular Biotechnology, Graduate School of Agriculture, Kyoto University, Japan
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36
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Itoh T, Ochiai A, Mikami B, Hashimoto W, Murata K. Structure of unsaturated rhamnogalacturonyl hydrolase complexed with substrate. Biochem Biophys Res Commun 2006; 347:1021-9. [PMID: 16870154 DOI: 10.1016/j.bbrc.2006.07.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 07/05/2006] [Indexed: 11/30/2022]
Abstract
Bacillus subtilis strain 168 YteR has been identified as a novel enzyme "unsaturated rhamnogalacturonyl hydrolase" classified in glycoside hydrolase family 105. This enzyme acts specifically on unsaturated rhamnogalacturonan (RG) produced from plant cell wall RG type-I treated with RG lyases, releasing unsaturated galacturonic acid (DeltaGalA) from the substrate. The most likely candidate catalytic residue is Asp-143. Here, we show the structure of D143N in complex with unsaturated RG disaccharide (substrate) determined at 1.9A resolution by X-ray crystallography. This structural feature directly contributes to the postulation of the enzyme reaction mechanism. YteR triggers the hydration of vinyl ether group in DeltaGalA, but not of glycoside bond, by using Asp-143 as a general acid and base catalyst. Asp-143 donates proton to the double bond of DeltaGalA as an acid catalyst and also deprotonates a water molecule as a base catalyst. Deprotonated water molecule attacks the C5 atom of DeltaGalA.
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Affiliation(s)
- Takafumi Itoh
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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37
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Rye CS, Matte A, Cygler M, Withers SG. An atypical approach identifies TYR234 as the key base catalyst in chondroitin AC lyase. Chembiochem 2006; 7:631-7. [PMID: 16521140 DOI: 10.1002/cbic.200500428] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chondroitin AC lyase from Flavobacterium heparinum catalyses the degradation of chondroitin by an anionic E1cb elimination mechanism that involves proton abstraction from C5 of glucuronic acid. The lyase also carries out efficient proton transfer to a sugar nitronate anion, which was designed originally as an inhibitor of the enzyme, with a second-order rate constant of kcat/Km=2.7x10(6) M(-1) s(-); this is very similar to that of the natural chondroitin substrate (kcat/Km=1.3x10(6) M(-1) s(-1)). Studies with this nitronate should therefore provide insight into the proton-transfer step (general base catalysis) within this mechanism. Indeed, the Tyr234Phe mutant of the enzyme was essentially inactive with the natural substrate and correspondingly did not catalyse proton transfer to the nitronate, thereby implicating this residue as the general base catalyst. Parallel studies designed to identify the acid catalyst were carried out by using a substrate with a 2,4-dinitrophenol leaving group that needs no acid assistance for departure. These results are consistent with Tyr234 also playing the role of acid catalyst. Not only do these studies confirm the suspected role of Tyr234, but also they validate a new methodology for identification of acid/base catalysts in lyases and epimerases of this type. In addition a structural and mechanistic rationale is provided for different active-site acid/base configurations in syn and anti lyases.
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Affiliation(s)
- Carl S Rye
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada
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38
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Suzuki H, Suzuki KI, Inoue A, Ojima T. A novel oligoalginate lyase from abalone, Haliotis discus hannai, that releases disaccharide from alginate polymer in an exolytic manner. Carbohydr Res 2006; 341:1809-19. [PMID: 16697989 DOI: 10.1016/j.carres.2006.04.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 04/05/2006] [Accepted: 04/13/2006] [Indexed: 11/22/2022]
Abstract
We previously reported the isolation and cDNA cloning of an endolytic alginate lyase, HdAly, from abalone Haliotis discus hannai [Carbohydr. Res.2003, 338, 2841-2852]. Although HdAly preferentially degraded mannuronate-rich substrates, it was incapable of degrading unsaturated oligomannuronates smaller than tetrasaccharide. In the present study, we used conventional chromatographic techniques to isolate a novel unsaturated-trisaccharide-degrading enzyme, named HdAlex, from the digestive fluid of the abalone. The HdAlex showed a molecular weight of 32,000 on SDS-PAGE and could degrade not only unsaturated trisaccharide but also alginate and mannuronate-rich polymers at an optimal pH and temperature of 7.1 and 42 degrees C, respectively. Upon digestion of alginate polymer, HdAlex decreased the viscosity of the alginate at a slower rate than did HdAly, producing only unsaturated disaccharide without any intermediate oligosaccharides. These results indicate that HdAlex degrades the alginate polymer in an exolytic manner. Because HdAlex split saturated trisaccharide producing unsaturated disaccharide, we considered that this enzyme cleaved the alginate at the second glycoside linkage from the reducing terminus. The primary structure of HdAlex was deduced with cDNAs amplified from an abalone hepatopancreas cDNA library by the polymerase chain reaction. The translational region of 822 bp in the total 887-bp sequence of HdAlex cDNA encoded an amino-acid sequence of 273 residues. The N-terminal sequence of 16 residues, excluding the initiation methionine, was regarded as the signal peptide of this enzyme. The amino-acid sequence of the remaining 256 residues shared 62-67% identities with those of the polysaccharide lyase family-14 (PL14) enzymes such as HdAly and turban-shell alginate lyase SP2. To our knowledge, HdAlex is the first exolytic oligoalginate lyase belonging to PL14.
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Affiliation(s)
- Harumasa Suzuki
- Laboratory of Marine Biotechnology and Microbiology, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Japan
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39
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Shaya D, Tocilj A, Li Y, Myette J, Venkataraman G, Sasisekharan R, Cygler M. Crystal structure of heparinase II from Pedobacter heparinus and its complex with a disaccharide product. J Biol Chem 2006; 281:15525-35. [PMID: 16565082 DOI: 10.1074/jbc.m512055200] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparinase II depolymerizes heparin and heparan sulfate glycosaminoglycans, yielding unsaturated oligosaccharide products through an elimination degradation mechanism. This enzyme cleaves the oligosaccharide chain on the nonreducing end of either glucuronic or iduronic acid, sharing this characteristic with a chondroitin ABC lyase. We have determined the first structure of a heparin-degrading lyase, that of heparinase II from Pedobacter heparinus (formerly Flavobacterium heparinum), in a ligand-free state at 2.15 A resolution and in complex with a disaccharide product of heparin degradation at 2.30 A resolution. The protein is composed of three domains: an N-terminal alpha-helical domain, a central two-layered beta-sheet domain, and a C-terminal domain forming a two-layered beta-sheet. Heparinase II shows overall structural similarities to the polysaccharide lyase family 8 (PL8) enzymes chondroitin AC lyase and hyaluronate lyase. In contrast to PL8 enzymes, however, heparinase II forms stable dimers, with the two active sites formed independently within each monomer. The structure of the N-terminal domain of heparinase II is also similar to that of alginate lyases from the PL5 family. A Zn2+ ion is bound within the central domain and plays an essential structural role in the stabilization of a loop forming one wall of the substrate-binding site. The disaccharide binds in a long, deep canyon formed at the top of the N-terminal domain and by loops extending from the central domain. Based on structural comparison with the lyases from the PL5 and PL8 families having bound substrates or products, the disaccharide found in heparinase II occupies the "+1" and "+2" subsites. The structure of the enzyme-product complex, combined with data from previously characterized mutations, allows us to propose a putative chemical mechanism of heparin and heparan-sulfate degradation.
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Affiliation(s)
- David Shaya
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
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40
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Ochiai A, Hashimoto W, Murata K. A biosystem for alginate metabolism in Agrobacterium tumefaciens strain C58: molecular identification of Atu3025 as an exotype family PL-15 alginate lyase. Res Microbiol 2006; 157:642-9. [PMID: 16545947 DOI: 10.1016/j.resmic.2006.02.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 02/01/2006] [Accepted: 02/09/2006] [Indexed: 11/30/2022]
Abstract
The Gram-negative bacterium Sphingomonas sp. strain A1 (strain A1) has a peculiar biosystem to directly import and depolymerize a macromolecule, alginate, which is encoded by a cluster of genes on the genome. We identified five clustered ORFs homologous to some genes of the strain A1 cluster in the genome of Agrobacterium tumefaciens strain C58 (strain C58). These ORFs are Atu3021, Atu3022, Atu3023, and Atu3024, encoding a putative sugar ABC transporter system and Atu3025, which encodes a putative alginate lyase. We analyzed the involvement of this gene cluster in alginate metabolism. Strain C58 cells grew significantly on low-molecular-weight (LMW) alginate (average molecular weight, 1000), and we detected specific alginate-induced expression of Atu3024 and Atu3025. This strain does not grow on alginate (average molecular weight, 25,600), suggesting that the strain C58 gene cluster is involved in importing and degrading LMW alginate. One protein, Atu3025, purified from strain C58, was identified as an alginate lyase, and the enzyme overexpressed in Escherichia coli was further characterized. Atu3025 released monosaccharides specifically from alginate most efficiently at pH 7.3 and 30 degrees C through a beta-elimination reaction, indicating that Atu3025 is an exotype alginate lyase potentially involved in the assimilation of LMW alginate in strain C58.
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Affiliation(s)
- Akihito Ochiai
- Laboratory of Basic and Applied Molecular Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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41
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Yamasaki M, Ogura K, Hashimoto W, Mikami B, Murata K. A Structural Basis for Depolymerization of Alginate by Polysaccharide Lyase Family-7. J Mol Biol 2005; 352:11-21. [PMID: 16081095 DOI: 10.1016/j.jmb.2005.06.075] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 06/25/2005] [Accepted: 06/29/2005] [Indexed: 11/21/2022]
Abstract
Alginate lyases depolymerize alginate, a heteropolysaccharide consisting of alpha-L-guluronate and beta-D-mannuronate, through a beta-elimination reaction. Their structure/function relationships are expected to provide information valuable to future industrial alginate processing and drug design for Pseudomonas aeruginosa alginate biofilm-dependent infection, but much remains unknown. Here, we present the crystal structure at 1.0 A resolution and the results of mutational analysis of Sphingomonas sp. A1 alginate lyase A1-II', which is grouped into the polysaccharide lyase (PL) family-7. The overall structure of A1-II' uses a beta-sandwich fold, and it has a large active cleft covered by two short flexible loops. Comparison with other family PL-7 structures indicated that loop opening is necessary for substrate binding when the catalytic reaction is initiated. In contrast to the disorder in many side-chains on the protein surface, the three adjacent beta-strands at the center of the active cleft are well ordered. This results from hydrogen bond networks and stacking-like associations identical with those in other family PL-7 structures. Disruption of these interactions by site-directed mutagenesis (R146A, E148A, R150A, Q189A, and K280A) makes the protein insoluble or greatly decreases its activity. The A1-II' structure includes two sulfate ions in the active cleft. Ammonium sulfate was a potent inhibitor with a Ki of 2.5 mM, indicating that our structure represents a model of the inhibitory state. Results of mutational analysis and continuous hydrogen bond networks suggest that Arg146, Gln189, His191, and Tyr284 form an active center. Tyr284OH appears particularly crucial to the catalytic reaction, which is supported by sulfate ion binding and the proximity to the C5 and O4 atoms of subsite +1 in the model obtained by energy minimization calculations using tri-mannuronate. The structural basis shown by this study is similar in many respects to that of the family PL-5 enzymes.
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Affiliation(s)
- Masayuki Yamasaki
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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42
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Maruyama Y, Hashimoto W, Mikami B, Murata K. Crystal Structure of Bacillus sp. GL1 Xanthan Lyase Complexed with a Substrate: Insights into the Enzyme Reaction Mechanism. J Mol Biol 2005; 350:974-86. [PMID: 15979090 DOI: 10.1016/j.jmb.2005.05.055] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2005] [Revised: 05/22/2005] [Accepted: 05/24/2005] [Indexed: 11/15/2022]
Abstract
Bacillus sp. GL1 xanthan lyase, a member of polysaccharide lyase family 8 (PL-8), acts exolytically on the side-chains of pentasaccharide-repeating polysaccharide xanthan and cleaves the glycosidic bond between glucuronic acid (GlcUA) and pyruvylated mannose (PyrMan) through a beta-elimination reaction. To clarify the enzyme reaction mechanism, i.e. its substrate recognition and catalytic reaction, we determined crystal structures of a mutant enzyme, N194A, in complexes with the product (PyrMan) and a substrate (pentasacharide) and in a ligand-free form at 1.8, 2.1, and 2.3A resolution. Based on the structures of the mutant in complexes with the product and substrate, we found that xanthan lyase recognized the PyrMan residue at subsite -1 and the GlcUA residue at +1 on the xanthan side-chain and underwent little interaction with the main chain of the polysaccharide. The structure of the mutant-substrate complex also showed that the hydroxyl group of Tyr255 was close to both the C-5 atom of the GlcUA residue and the oxygen atom of the glycosidic bond to be cleaved, suggesting that Tyr255 likely acts as a general base that extracts the proton from C-5 of the GlcUA residue and as a general acid that donates the proton to the glycosidic bond. A structural comparison of catalytic centers of PL-8 lyases indicated that the catalytic reaction mechanism is shared by all members of the family PL-8, while the substrate recognition mechanism differs.
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Affiliation(s)
- Yukie Maruyama
- Laboratory of Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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43
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Albrecht MT, Schiller NL. Alginate lyase (AlgL) activity is required for alginate biosynthesis in Pseudomonas aeruginosa. J Bacteriol 2005; 187:3869-72. [PMID: 15901714 PMCID: PMC1112040 DOI: 10.1128/jb.187.11.3869-3872.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To determine whether AlgL's lyase activity is required for alginate production in Pseudomonas aeruginosa, an algLdelta::Gm(r) mutant (FRD-MA7) was created. algL complementation of FRD-MA7 restored alginate production, but algL constructs containing mutations inactivating lyase activity did not, demonstrating that the enzymatic activity of AlgL is required for alginate production.
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Affiliation(s)
- Mark T Albrecht
- Division of Biomedical Sciences, University of California, Riverside, Riverside, California 92521-0121, USA
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44
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Yamasaki M, Ogura K, Moriwaki S, Hashimoto W, Murata K, Mikami B. Crystallization and preliminary X-ray analysis of alginate lyases A1-II and A1-II' from Sphingomonas sp. A1. Acta Crystallogr Sect F Struct Biol Cryst Commun 2005; 61:288-90. [PMID: 16511020 PMCID: PMC1952290 DOI: 10.1107/s174430910500299x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 01/27/2005] [Indexed: 11/10/2022]
Abstract
Alginate lyases depolymerize alginate, a heteropolysaccharide consisting of alpha-L-guluronate and beta-D-mannuronate, through a beta-elimination reaction. The alginate lyases A1-II (25 kDa) and A1-II' (25 kDa) from Sphingomonas sp. A1, which belong to polysaccharide lyase family PL-7, exhibit 68% homology in primary structure but have different substrate specificities. To determine clearly the structural basis for substrate recognition in the depolymerization mechanism by alginate lyases, both proteins were crystallized at 293 K using the vapour-diffusion method. A crystal of A1-II belonged to space group P2(1) and diffracted to 2.2 A resolution, with unit-cell parameters a = 51.3, b = 30.1, c = 101.6 A, beta = 100.2 degrees, while a crystal of A1-II' belonged to space group P2(1)2(1)2(1) and diffracted to 1.0 A resolution, with unit-cell parameters a = 34.6, b = 68.5, c = 80.3 A.
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Affiliation(s)
- Masayuki Yamasaki
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kohei Ogura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Satoko Moriwaki
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Wataru Hashimoto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kousaku Murata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Bunzo Mikami
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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45
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Osawa T, Matsubara Y, Muramatsu T, Kimura M, Kakuta Y. Crystal Structure of the Alginate (Poly α-l-guluronate) Lyase from Corynebacterium sp. at 1.2Å Resolution. J Mol Biol 2005; 345:1111-8. [PMID: 15644208 DOI: 10.1016/j.jmb.2004.10.081] [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] [Received: 06/29/2004] [Revised: 10/23/2004] [Accepted: 10/28/2004] [Indexed: 11/23/2022]
Abstract
The crystal structure of alginate (poly alpha-l-guluronate) lyase from Corynebacterium sp. (ALY-1) was determined at 1.2A resolution using the MAD method and bromide ions. The structure of ALY-1 is abundant in beta-strands and has a deep cleft, similar to the jellyroll beta-sandwich found in 1,3-1,4-beta-glucanase. The structure suggests that alginate molecules may penetrate into the cleft to interact with the catalytic site of ALY-1. The reported crystal structure of another type of alginate lyase, A1-III, differs from that of ALY-1 in that it consists almost entirely of alpha-helical structure. Nevertheless, the putative catalytic residues in both enzymes are positioned in space in nearly identical arrangements. This finding suggests that both alginate lyases may have evolved through convergent evolution.
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Affiliation(s)
- Takuo Osawa
- Laboratory of Biochemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
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Abstract
Here, we report a novel protein sequence descriptor-based remote homology identification method, able to infer fold relationships without the explicit knowledge of structure. In a first phase, we have individually benchmarked 13 different descriptor types in fold identification experiments in a highly diverse set of protein sequences. The relevant descriptors were related to the fold class membership by using simple similarity measures in the descriptor spaces, such as the cosine angle. Our results revealed that the three best-performing sets of descriptors were the sequence-alignment-based descriptor using PSI-BLAST e-values, the descriptors based on the alignment of secondary structural elements (SSEA), and the descriptors based on the occurrence of PROSITE functional motifs. In a second phase, the three top-performing descriptors were combined to obtain a final method with improved performance, which we named DescFold. Class membership was predicted by Support Vector Machine (SVM) learning. In comparison with the individual PSI-BLAST-based descriptor, the rate of remote homology identification increased from 33.7% to 46.3%. We found out that the composite set of descriptors was able to identify the true remote homolog for nearly every sixth sequence at the 95% confidence level, or some 10% more than a single PSI-BLAST search. We have benchmarked the DescFold method against several other state-of-the-art fold recognition algorithms for the 172 LiveBench-8 targets, and we concluded that it was able to add value to the existing techniques by providing a confident hit for at least 10% of the sequences not identifiable by the previously known methods.
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Affiliation(s)
- Ziding Zhang
- Nestlé Research Center, BioAnalyti-cal Science, CH-1000 Lausanne 26, Switzerland. Ziding.
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Campa C, Holtan S, Nilsen N, Bjerkan T, Stokke B, SKJåK-BRæK G. Biochemical analysis of the processive mechanism for epimerization of alginate by mannuronan C-5 epimerase AlgE4. Biochem J 2004; 381:155-64. [PMID: 15032753 PMCID: PMC1133773 DOI: 10.1042/bj20031265] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2003] [Revised: 03/05/2004] [Accepted: 03/19/2004] [Indexed: 11/17/2022]
Abstract
The enzymes mannuronan C-5 epimerases catalyse the in-chain epimerisation of beta-D-mannuronic acid to alpha-L-guluronic acid in the last step of alginate biosynthesis. The recombinant C-5 epimerase AlgE4, encoded by the soil bacteria Azotobacter vinelandii and expressed in Escherichia coli, exhibits a non-random mode of action when acting on mannuronan and alginates of various monomeric compositions. The observed residue sequence has been suggested previously to be due to either a preferred attack or a processive mode of action. Based on methodologies involving specific degrading enzymes, NMR, electrospray ionisation mass spectrometry and capillary electrophoresis we show here that on average 10 residues are epimerised for each enzyme-substrate encounter. A subsite model for the enzyme is analysed by the same methodology using native and 13C-labelled mannuronan oligomers as substrate for the AlgE4 epimerase. A hexameric oligomer is the minimum size to accommodate activity. For hexa-, hepta- and octameric substrates the third M residue from the non-reducing end is epimerised first.
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Affiliation(s)
- Cristiana Campa
- *Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, Italy
| | - Synnøve Holtan
- †Norwegian Biopolymer Laboratory, Department of Biotechnology, The University of Science and Technology NTNU, Trondheim, Norway
| | - Nadra Nilsen
- †Norwegian Biopolymer Laboratory, Department of Biotechnology, The University of Science and Technology NTNU, Trondheim, Norway
| | - Tonje M. Bjerkan
- †Norwegian Biopolymer Laboratory, Department of Biotechnology, The University of Science and Technology NTNU, Trondheim, Norway
| | - Bjørn T. Stokke
- ‡Department of Physics, The University of Science and Technology NTNU, Trondheim, Norway
| | - Gudmund SKJåK-BRæK
- †Norwegian Biopolymer Laboratory, Department of Biotechnology, The University of Science and Technology NTNU, Trondheim, Norway
- To whom correspondence should be addressed (e-mail )
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Itoh T, Akao S, Hashimoto W, Mikami B, Murata K. Crystal Structure of Unsaturated Glucuronyl Hydrolase, Responsible for the Degradation of Glycosaminoglycan, from Bacillus sp. GL1 at 1.8 Å Resolution. J Biol Chem 2004; 279:31804-12. [PMID: 15148314 DOI: 10.1074/jbc.m403288200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Unsaturated glucuronyl hydrolase (UGL) is a novel glycosaminoglycan hydrolase that releases unsaturated d-glucuronic acid from oligosaccharides produced by polysaccharide lyases. The x-ray crystallographic structure of UGL from Bacillus sp. GL1 was first determined by multiple isomorphous replacement (mir) and refined at 1.8 A resolution with a final R-factor of 16.8% for 25 to 1.8 A resolution data. The refined UGL structure consists of 377 amino acid residues and 478 water molecules, four glycine molecules, two dithiothreitol (DTT) molecules, and one 2-methyl-2,4-pentanediol (MPD) molecule. UGL includes an alpha(6)/alpha(6)-barrel, whose structure is found in the six-hairpin enzyme superfamily of an alpha/alpha-toroidal fold. One side of the UGL alpha(6)/alpha(6)-barrel structure consists of long loops containing three short beta-sheets and contributes to the formation of a deep pocket. One glycine molecule and two DTT molecules surrounded by highly conserved amino acid residues in UGLs were found in the pocket, suggesting that catalytic and substrate-binding sites are located in this pocket. The overall UGL structure, with the exception of some loops, very much resembled that of the Bacillus subtilis hypothetical protein Yter, whose function is unknown and which exhibits little amino acid sequence identity with UGL. In the active pocket, residues possibly involved in substrate recognition and catalysis by UGL are conserved in UGLs and Yter. The most likely candidate catalytic residues for glycosyl hydrolysis are Asp(88) and Asp(149). This was supported by site-directed mutagenesis studies in Asp(88) and Asp(149).
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Affiliation(s)
- Takafumi Itoh
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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Yamasaki M, Moriwaki S, Miyake O, Hashimoto W, Murata K, Mikami B. Structure and Function of a Hypothetical Pseudomonas aeruginosa Protein PA1167 Classified into Family PL-7. J Biol Chem 2004; 279:31863-72. [PMID: 15136569 DOI: 10.1074/jbc.m402466200] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Structural and functional analyses of alginate lyases are important in the clarification of the biofilm-dependent ecosystem in Pseudomonas aeruginosa and in the development of therapeutic agents for bacterial disease. Most alginate lyases are classified into polysaccharide lyase (PL) family-5 and -7 based on their primary structures. Family PL-7 enzymes are still poorly characterized especially in structural properties. Among family PL-7, a gene coding for a hypothetical protein (PA1167) homologous to Sphingomonas alginate lyase A1-II was found to be present in the P. aeruginosa genome. PA1167 overexpressed in Escherichia coli cleaved glycosidic bonds in alginate and released unsaturated saccharides, indicating that PA1167 is an alginate lyase catalyzing a beta-elimination reaction. The enzyme acted preferably on heteropolymeric regions endolytically and worked most efficiently at pH 8.5 and 40 degrees C. The specific activity of PA1167, however, was much weaker than that of the known alginate lyase AlgL, suggesting that AlgL plays a main role in alginate depolymerization in P. aeruginosa. In addition to this specific activity, differences were found between PA1167 and AlgL in enzyme properties such as molecular mass, optimum pH, salt effect, and substrate specificity. The first crystal structure of the family PL-7 alginate lyase was determined at 2.0 A resolution. PA1167 was found to form a glove-like beta-sandwich composed of 15 beta-strands and 3 alpha-helices. The structural difference between the beta-sandwich PA1167 of family PL-7 and alpha/alpha-barrel AlgL of family PL-5 may be responsible for the enzyme characteristics. Crystal structures of polysaccharide lyases determined so far indicate that they can be assigned to three folding groups having parallel beta-helix, alpha/alpha-barrel, and alpha/alpha-barrel + antiparallel beta-sheet structures as basic frames. PA1167 is the fourth novel folding structure found among polysaccharide lyases.
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Affiliation(s)
- Masayuki Yamasaki
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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Hudáky I, Gáspári Z, Carugo O, Cemazar M, Pongor S, Perczel A. Vicinal disulfide bridge conformers by experimental methods and by ab initio and DFT molecular computations. Proteins 2004; 55:152-68. [PMID: 14997549 DOI: 10.1002/prot.10581] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A systematic comparison is made between experimental and computational data gained on vicinal disulfide bridges in proteins and peptides. Structural and stability data of ab initio and density functional theory (DFT) calculations on the model compound 4,5-ditiaheptano-7-lactam and the model peptide HCO-ox-[Cys-Cys]-NH2 at RHF/3-21G*, B3LYP/6-31+G(d), and B3LYP/6-311++G(d,p) levels of theory are presented. The data on Xxx-Cys-Cys-Yyy type amino acid sequence units retrieved from PDB SELECT, along with data on sequence units that have vicinal disulfide bridge, taken from the Brookhaven Protein Data Bank, are conformationally characterized. Amino acid backbone conformations, cis-trans isomerism of the amide bond between the two cysteine residues, and ring puckering are studied. Ring puckers are characterized by their relation to the conformers of the parent 4,5-ditiaheptano-7-lactam. Computational precision and accuracy are proved by frequency calculation and solvent model optimization on selected conformers. It is found that the ox-[Cys-Cys] unit is able to accept types I, II, VIa, VIb, and VIII beta-turn structures.
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Affiliation(s)
- Ilona Hudáky
- Department of Organic Chemistry, Eötvös Loránd University, Budapest, Hungary
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