1
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Gao X, Bian T, Gao P, Ge X, Zhang Y, Han J, Guo X, Zhou L, Yang H. Fidelity Characterization of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and NADC30-like Strain. Viruses 2024; 16:797. [PMID: 38793678 PMCID: PMC11125636 DOI: 10.3390/v16050797] [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: 04/23/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) has significantly impacted the global pork industry for over three decades. Its high mutation rates and frequent recombination greatly intensifies its epidemic and threat. To explore the fidelity characterization of Chinese highly pathogenic PRRSV JXwn06 and the NADC30-like strain CHsx1401, self-recombination and mutation in PAMs, MARC-145 cells, and pigs were assessed. In vitro, CHsx1401 displayed a higher frequency of recombination junctions and a greater diversity of junction types than JXwn06. In vivo, CHsx1401 exhibited fewer junction types yet maintained a higher junction frequency. Notably, JXwn06 showed more accumulation of mutations. To pinpoint the genomic regions influencing their fidelity, chimeric viruses were constructed, with the exchanged nsp9-10 regions between JXwn06 and CHsx1401. The SJn9n10 strain, which incorporates JXwn06's nsp9-10 into the CHsx1401 genome, demonstrated reduced sensitivity to nucleotide analogs compared to CHsx1401. Conversely, compared with JXwn06, the JSn9n10 strain showed increased sensitivity to these inhibitors. The swapped nsp9-10 also influences the junction frequency and accumulated mutations as their donor strains. The results indicate a propensity for different types of genetic variations between these two strains and further highlight the nsp9-10 region as a critical determinant of their fidelity.
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Affiliation(s)
- Xiang Gao
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Ting Bian
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Peng Gao
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Xinna Ge
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Yongning Zhang
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Jun Han
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Xin Guo
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Lei Zhou
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Hanchun Yang
- National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; (X.G.)
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
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2
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Haase N, Holtkamp W, Christ S, Heinemann D, Rodnina MV, Rudorf S. Decomposing bulk signals to reveal hidden information in processive enzyme reactions: A case study in mRNA translation. PLoS Comput Biol 2024; 20:e1011918. [PMID: 38442108 PMCID: PMC10942256 DOI: 10.1371/journal.pcbi.1011918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 03/15/2024] [Accepted: 02/14/2024] [Indexed: 03/07/2024] Open
Abstract
Processive enzymes like polymerases or ribosomes are often studied in bulk experiments by monitoring time-dependent signals, such as fluorescence time traces. However, due to biomolecular process stochasticity, ensemble signals may lack the distinct features of single-molecule signals. Here, we demonstrate that, under certain conditions, bulk signals from processive reactions can be decomposed to unveil hidden information about individual reaction steps. Using mRNA translation as a case study, we show that decomposing a noisy ensemble signal generated by the translation of mRNAs with more than a few codons is an ill-posed problem, addressable through Tikhonov regularization. We apply our method to the fluorescence signatures of in-vitro translated LepB mRNA and determine codon-position dependent translation rates and corresponding state-specific fluorescence intensities. We find a significant change in fluorescence intensity after the fourth and the fifth peptide bond formation, and show that both codon position and encoded amino acid have an effect on the elongation rate. This demonstrates that our approach enhances the information content extracted from bulk experiments, thereby expanding the range of these time- and cost-efficient methods.
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Affiliation(s)
- Nadin Haase
- Leibniz University Hannover, Institute of Cell Biology and Biophysics, Hannover, Germany
| | - Wolf Holtkamp
- Max Planck Institute for Multidisciplinary Sciences, Department of Physical Biochemistry, Göttingen, Germany
- Paul-Ehrlich-Institut, Division of Allergology, Langen, Germany
| | - Simon Christ
- Leibniz University Hannover, Institute of Cell Biology and Biophysics, Hannover, Germany
| | - Dag Heinemann
- Leibniz University Hannover, Hannover Centre for Optical Technologies (HOT), Hannover, Germany
- Leibniz University Hannover, Institute of Horticultural Production Systems, Hannover, Germany
- Leibniz University Hannover, PhoenixD Cluster of Excellence, Hannover, Germany
| | - Marina V. Rodnina
- Max Planck Institute for Multidisciplinary Sciences, Department of Physical Biochemistry, Göttingen, Germany
| | - Sophia Rudorf
- Leibniz University Hannover, Institute of Cell Biology and Biophysics, Hannover, Germany
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3
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Simpson M, Harding CJ, Czekster RM, Remmel L, Bode BE, Czekster CM. Unveiling the Catalytic Mechanism of a Processive Metalloaminopeptidase. Biochemistry 2023; 62:3188-3205. [PMID: 37924287 PMCID: PMC10666288 DOI: 10.1021/acs.biochem.3c00420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 11/06/2023]
Abstract
Intracellular leucine aminopeptidases (PepA) are metalloproteases from the family M17. These enzymes catalyze peptide bond cleavage, removing N-terminal residues from peptide and protein substrates, with consequences for protein homeostasis and quality control. While general mechanistic studies using model substrates have been conducted on PepA enzymes from various organisms, specific information about their substrate preferences and promiscuity, choice of metal, activation mechanisms, and the steps that limit steady-state turnover remain unexplored. Here, we dissected the catalytic and chemical mechanisms of PaPepA: a leucine aminopeptidase from Pseudomonas aeruginosa. Cleavage assays using peptides and small-molecule substrate mimics allowed us to propose a mechanism for catalysis. Steady-state and pre-steady-state kinetics, pH rate profiles, solvent kinetic isotope effects, and biophysical techniques were used to evaluate metal binding and activation. This revealed that metal binding to a tight affinity site is insufficient for enzyme activity; binding to a weaker affinity site is essential for catalysis. Progress curves for peptide hydrolysis and crystal structures of free and inhibitor-bound PaPepA revealed that PaPepA cleaves peptide substrates in a processive manner. We propose three distinct modes for activity regulation: tight packing of PaPepA in a hexameric assembly controls substrate length and reaction processivity; the product leucine acts as an inhibitor, and the high concentration of metal ions required for activation limits catalytic turnover. Our work uncovers catalysis by a metalloaminopeptidase, revealing the intricacies of metal activation and substrate selection. This will pave the way for a deeper understanding of metalloenzymes and processive peptidases/proteases.
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Affiliation(s)
- Martha
Clementine Simpson
- School
of Biology, University of St Andrews, North Haugh, Biomolecular Sciences
Building, KY16 9ST, Saint Andrews, United Kingdom
| | - Christopher John Harding
- School
of Biology, University of St Andrews, North Haugh, Biomolecular Sciences
Building, KY16 9ST, Saint Andrews, United Kingdom
| | - Ricardo Melo Czekster
- School
of Computer Science and Digital Technologies, Department of Software
Engineering and Cybersecurity, Aston University, B4 7ET, Birmingham,United Kingdom
| | - Laura Remmel
- School
of Chemistry, University of St Andrews, North Haugh, Purdie Building, KY16 9ST, Saint Andrews , United Kingdom
| | - Bela E. Bode
- School
of Chemistry, University of St Andrews, North Haugh, Purdie Building, KY16 9ST, Saint Andrews , United Kingdom
| | - Clarissa Melo Czekster
- School
of Biology, University of St Andrews, North Haugh, Biomolecular Sciences
Building, KY16 9ST, Saint Andrews, United Kingdom
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4
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Kang Q, Chu M, Xu P, Wang X, Wang S, Cao M, Ivasenko O, Sham TK, Zhang Q, Sun Q, Chen J. Entropy Confinement Promotes Hydrogenolysis Activity for Polyethylene Upcycling. Angew Chem Int Ed Engl 2023; 62:e202313174. [PMID: 37799095 DOI: 10.1002/anie.202313174] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/26/2023] [Accepted: 10/05/2023] [Indexed: 10/07/2023]
Abstract
Chemical upcycling that catalyzes waste plastics back to high-purity chemicals holds great promise in end-of-life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilization of the transition state. This approach involves the synthesis of p-Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA-15 support, using a precise impregnation method. The unique design of the p-Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high-value liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g ⋅ gRu -1 ⋅ h-1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2 , and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics.
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Affiliation(s)
- Qingyun Kang
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Mingyu Chu
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, P. R. China
| | - Panpan Xu
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Xuchun Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
- Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Shiqi Wang
- Innovation Center for Chemical Sciences, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Muhan Cao
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Oleksandr Ivasenko
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Tsun-Kong Sham
- Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Qiao Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Qiming Sun
- Innovation Center for Chemical Sciences, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Jinxing Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
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5
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Harding CJ, Bischoff M, Bergkessel M, Czekster CM. An anti-biofilm cyclic peptide targets a secreted aminopeptidase from P. aeruginosa. Nat Chem Biol 2023; 19:1158-1166. [PMID: 37386135 PMCID: PMC10449631 DOI: 10.1038/s41589-023-01373-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 05/26/2023] [Indexed: 07/01/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes serious illness, especially in immunocompromised individuals. P. aeruginosa forms biofilms that contribute to growth and persistence in a wide range of environments. Here we investigated the aminopeptidase, P. aeruginosa aminopeptidase (PaAP) from P. aeruginosa, which is highly abundant in the biofilm matrix. PaAP is associated with biofilm development and contributes to nutrient recycling. We confirmed that post-translational processing was required for activation and PaAP is a promiscuous aminopeptidase acting on unstructured regions of peptides and proteins. Crystal structures of wild-type enzymes and variants revealed the mechanism of autoinhibition, whereby the C-terminal propeptide locks the protease-associated domain and the catalytic peptidase domain into a self-inhibited conformation. Inspired by this, we designed a highly potent small cyclic-peptide inhibitor that recapitulates the deleterious phenotype observed with a PaAP deletion variant in biofilm assays and present a path toward targeting secreted proteins in a biofilm context.
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Affiliation(s)
- Christopher John Harding
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, UK
| | - Marcus Bischoff
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, UK
- Centre of Biophotonics, University of St Andrews, St Andrews, UK
| | | | - Clarissa Melo Czekster
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, UK.
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6
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Tennakoon A, Wu X, Meirow M, Howell D, Willmon J, Yu J, Lamb JV, Delferro M, Luijten E, Huang W, Sadow AD. Two Mesoporous Domains Are Better Than One for Catalytic Deconstruction of Polyolefins. J Am Chem Soc 2023; 145:17936-17944. [PMID: 37540829 DOI: 10.1021/jacs.3c05447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2023]
Abstract
Catalytic hydrogenolysis of polyolefins into valuable liquid, oil, or wax-like hydrocarbon chains for second-life applications is typically accompanied by the hydrogen-wasting co-formation of low value volatiles, notably methane, that increase greenhouse gas emissions. Catalytic sites confined at the bottom of mesoporous wells, under conditions in which the pore exerts the greatest influence over the mechanism, are capable of producing less gases than unconfined sites. A new architecture was designed to emphasize this pore effect, with the active platinum nanoparticles embedded between linear, hexagonal mesoporous silica and gyroidal cubic MCM-48 silica (mSiO2/Pt/MCM-48). This catalyst deconstructs polyolefins selectively into ∼C20-C40 paraffins and cleaves C-C bonds at a rate (TOF = 4.2 ± 0.3 s-1) exceeding that of materials lacking these combined features while generating negligible volatile side products including methane. The time-independent product distribution is consistent with a processive mechanism for polymer deconstruction. In contrast to time- and polymer length-dependent products obtained from non-porous catalysts, mSiO2/Pt/MCM-48 yields a C28-centered Gaussian distribution of waxy hydrocarbons from polyolefins of varying molecular weight, composition, and physical properties, including low-density polyethylene, isotactic polypropylene, ultrahigh-molecular-weight polyethylene, and mixtures of multiple, post-industrial polyolefins. Coarse-grained simulation reveals that the porous-core architecture enables the paraffins to diffuse away from the active platinum site, preventing secondary reactions that produce gases.
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Affiliation(s)
- Akalanka Tennakoon
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Chemical and Biological Sciences Division, Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Xun Wu
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Chemical and Biological Sciences Division, Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Max Meirow
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Daniel Howell
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Jarod Willmon
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Jiaqi Yu
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Jessica V Lamb
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Erik Luijten
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois 60208, United States
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Wenyu Huang
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Chemical and Biological Sciences Division, Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Aaron D Sadow
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Chemical and Biological Sciences Division, Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
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7
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Bocanegra R, Ortíz-Rodríguez M, Zumeta L, Plaza-G A I, Faro E, Ibarra B. DNA replication machineries: Structural insights from crystallography and electron microscopy. Enzymes 2023; 54:249-271. [PMID: 37945174 DOI: 10.1016/bs.enz.2023.07.004] [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] [Indexed: 11/12/2023]
Abstract
Since the discovery of DNA as the genetic material, scientists have been investigating how the information contained in this biological polymer is transmitted from generation to generation. X-ray crystallography, and more recently, cryo-electron microscopy techniques have been instrumental in providing essential information about the structure, functions and interactions of the DNA and the protein machinery (replisome) responsible for its replication. In this chapter, we highlight several works that describe the structure and structure-function relationships of the core components of the prokaryotic and eukaryotic replisomes. We also discuss the most recent studies on the structural organization of full replisomes.
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Affiliation(s)
| | | | - Lyra Zumeta
- IMDEA Nanociencia, Campus Cantoblanco, Madrid, Spain
| | | | - Elías Faro
- IMDEA Nanociencia, Campus Cantoblanco, Madrid, Spain
| | - Borja Ibarra
- IMDEA Nanociencia, Campus Cantoblanco, Madrid, Spain.
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8
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Tincu (Iurciuc) CE, Bouhadiba B, Atanase LI, Stan CS, Popa M, Ochiuz L. An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg 2+ Ions. Molecules 2023; 28:4695. [PMID: 37375250 PMCID: PMC10302431 DOI: 10.3390/molecules28124695] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Amylase is an enzyme used to hydrolyze starch in order to obtain different products that are mainly used in the food industry. The results reported in this article refer to the immobilization of α-amylase in gellan hydrogel particles ionically cross-linked with Mg2+ ions. The obtained hydrogel particles were characterized physicochemically and morphologically. Their enzymatic activity was tested using starch as a substrate in several hydrolytic cycles. The results showed that the properties of the particles are influenced by the degree of cross-linking and the amount of immobilized α-amylase enzyme. The temperature and pH at which the immobilized enzyme activity is maximum were T = 60 °C and pH = 5.6. The enzymatic activity and affinity of the enzyme to the substrate depend on the particle type, and this decreases for particles with a higher cross-linking degree owing to the slow diffusion of the enzyme molecules inside the polymer's network. By immobilization, α-amylase is protected from environmental factors, and the obtained particles can be quickly recovered from the hydrolysis medium, thus being able to be reused in repeated hydrolytic cycles (at least 11 cycles) without a substantial decrease in enzymatic activity. Moreover, α-amylase immobilized in gellan particles can be reactivated via treatment with a more acidic medium.
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Affiliation(s)
- Camelia Elena Tincu (Iurciuc)
- Department of Natural and Synthetic Polymers, “Cristofor Simionescu” Faculty of Chemical Engineering and Protection of the Environment, “Gheorghe Asachi” Technical University, 73, Prof. Dr. Docent Dimitrie Mangeron Street, 700050 Iași, Romania; (C.E.T.)
- Department of Pharmaceutical Technology, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine and Pharmacy, 16, University Street, 700115 Iaşi, Romania
| | - Brahim Bouhadiba
- Laboratory of Engineering of Industrial Safety and Sustainable Development LISIDD, Institute of Maintenance and Industrial Safety, University of Oran 2, Mohammed Benahmed, Oran 31000, Algeria
| | - Leonard Ionut Atanase
- Faculty of Dental Medicine, “Apollonia” University of Iasi, 11, Pacurari Street, 700511 Iași, Romania
- Academy of Romanian Scientists, 050045 Bucharest, Romania
| | - Corneliu Sergiu Stan
- Department of Natural and Synthetic Polymers, “Cristofor Simionescu” Faculty of Chemical Engineering and Protection of the Environment, “Gheorghe Asachi” Technical University, 73, Prof. Dr. Docent Dimitrie Mangeron Street, 700050 Iași, Romania; (C.E.T.)
| | - Marcel Popa
- Department of Natural and Synthetic Polymers, “Cristofor Simionescu” Faculty of Chemical Engineering and Protection of the Environment, “Gheorghe Asachi” Technical University, 73, Prof. Dr. Docent Dimitrie Mangeron Street, 700050 Iași, Romania; (C.E.T.)
- Academy of Romanian Scientists, 050045 Bucharest, Romania
| | - Lăcrămioara Ochiuz
- Department of Pharmaceutical Technology, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine and Pharmacy, 16, University Street, 700115 Iaşi, Romania
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9
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Kuch NJ, Kutschke ME, Parker A, Bingman CA, Fox BG. Contribution of calcium ligands in substrate binding and product release in the Acetovibrio thermocellus glycoside hydrolase family 9 cellulase CelR. J Biol Chem 2023; 299:104655. [PMID: 36990218 PMCID: PMC10149213 DOI: 10.1016/j.jbc.2023.104655] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Enzymatic deconstruction of lignocellulosic biomass is crucial to establishment of the renewable biofuel and bioproduct economy. Better understanding of these enzymes, including their catalytic and binding domains, and other features offer potential avenues for improvement. Glycoside hydrolase family 9 (GH9) enzymes are attractive targets because they have members that exhibit exo- and endo-cellulolytic activity, processivity of reaction, and thermostability. This study examines a GH9 from Acetovibrio thermocellus ATCC 27405, AtCelR containing a catalytic domain and a carbohydrate binding module (CBM3c). Crystal structures of the enzyme without substrate, bound to cellohexaose (substrate) or cellobiose (product), show the positioning of ligands to calcium and adjacent residues in the catalytic domain that may contribute to substrate binding and facilitate product release. We also investigated the properties of the enzyme engineered to contain an additional carbohydrate binding module (CBM3a). Relative to the catalytic domain alone, CBM3a gave improved binding for Avicel (a crystalline form of cellulose), and catalytic efficiency (kcat/KM) was improved 40× with both CBM3c and CBM3a present. However, because of the molecular weight added by CBM3a, the specific activity of the engineered enzyme was not increased relative to the native construct consisting of only the catalytic and CBM3c domains. This work provides new insight into a potential role of the conserved calcium in the catalytic domain and identifies contributions and limitations of domain engineering for AtCelR and perhaps other GH9 enzymes.
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Affiliation(s)
- Nathaniel J Kuch
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark E Kutschke
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alex Parker
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; Dane County Youth Apprenticeship Program, Dane County School Consortium, Monona, Wisconsin, USA
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; Collaborative Crystallography Core, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Brian G Fox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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10
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Controlled processivity in glycosyltransferases: A way to expand the enzymatic toolbox. Biotechnol Adv 2023; 63:108081. [PMID: 36529206 DOI: 10.1016/j.biotechadv.2022.108081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/20/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
Glycosyltransferases (GT) catalyse the biosynthesis of complex carbohydrates which are the most abundant group of molecules in nature. They are involved in several key mechanisms such as cell signalling, biofilm formation, host immune system invasion or cell structure and this in both prokaryotic and eukaryotic cells. As a result, research towards complete enzyme mechanisms is valuable to understand and elucidate specific structure-function relationships in this group of molecules. In a next step this knowledge could be used in GT protein engineering, not only for rational drug design but also for multiple biotechnological production processes, such as the biosynthesis of hyaluronan, cellooligosaccharides or chitooligosaccharides. Generation of these poly- and/or oligosaccharides is possible due to a common feature of several of these GTs: processivity. Enzymatic processivity has the ability to hold on to the growing polymer chain and some of these GTs can even control the number of glycosyl transfers. In a first part, recent advances in understanding the mechanism of various processive enzymes are discussed. To this end, an overview is given of possible engineering strategies for the purpose of new industrial and fundamental applications. In the second part of this review, we focused on specific chain length-controlling mechanisms, i.e., key residues or conserved regions, and this for both eukaryotic and prokaryotic enzymes.
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11
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Li P, Wang X, Zhang C, Xu D. Processive binding mechanism of Cel9G from Clostridium cellulovorans: molecular dynamics and free energy landscape investigations. Phys Chem Chem Phys 2023; 25:646-657. [DOI: 10.1039/d2cp04830b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The processive binding mechanism of cellulose by Cel9G from C. cellulovorans was investigated by MD and metadynamics simulations.
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Affiliation(s)
- Penghui Li
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Sichuan, Chengdu, 610064, P. R. China
| | - Xin Wang
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Sichuan, Chengdu, 610064, P. R. China
| | - Chunchun Zhang
- Analytical & Testing Center, Sichuan University, Sichuan, Chengdu, 610064, P. R. China
| | - Dingguo Xu
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Sichuan, Chengdu, 610064, P. R. China
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12
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Cao S, Li L, Zhu B, Yao Z. Alginate modifying enzymes: An updated comprehensive review of the mannuronan C5-epimerases. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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13
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Yappert R, Peters B. Processive Depolymerization Catalysts: A Population Balance Model for Chemistry’s “While” Loop. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ryan Yappert
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Baron Peters
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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14
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Ding N, Zhao B, Han X, Li C, Gu Z, Li Z. Starch-Binding Domain Modulates the Specificity of Maltopentaose Production at Moderate Temperatures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:9057-9065. [PMID: 35829707 DOI: 10.1021/acs.jafc.2c03031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Maltooligosaccharide-forming amylases (MFAs) hydrolyze starch into maltooligosaccharides with a defined degree of polymerization. However, the enzymatic mechanism underlying the product specificity remains partially understood. Here, we show that Saccharophagus degradans MFA (SdMFA) contains a noncatalytic starch-binding domain (SBD), which belongs to the carbohydrate-binding module family 20 and enables modulation of the product specificity. Removal of SBD from SdMFA resulted in a 3.5-fold lower production of the target maltopentaose. Conversely, appending SBD to another MFA from Bacillus megaterium improved the specificity for maltopentaose. SdMFA exhibited a higher level of exo-action and greater product specificity when reacting with amylopectin than with amylose. Our structural analysis and molecular dynamics simulation suggested that SBD could promote the recognition of nonreducing ends of substrates and delivery of the substrate chain to a groove end toward the active site in the catalytic domain. Furthermore, we demonstrate that a moderate temperature could mediate SBD to interact with the substrate with loose affinity, which facilitates the substrate to slide toward the active site. Together, our study reveals the structural and conditional bases for the specificity of MFAs, providing generalizable strategies to engineer MFAs and optimize the biosynthesis of maltooligosaccharides.
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Affiliation(s)
- Ning Ding
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Boyang Zhao
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Xu Han
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Caiming Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center for Food Safety and Quality Control, Jiangnan University, Wuxi 214122, China
| | - Zhengbiao Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center for Food Safety and Quality Control, Jiangnan University, Wuxi 214122, China
| | - Zhaofeng Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center for Food Safety and Quality Control, Jiangnan University, Wuxi 214122, China
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15
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Yang RX, Jan K, Chen CT, Chen WT, Wu KCW. Thermochemical Conversion of Plastic Waste into Fuels, Chemicals, and Value-Added Materials: A Critical Review and Outlooks. CHEMSUSCHEM 2022; 15:e202200171. [PMID: 35349769 DOI: 10.1002/cssc.202200171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/27/2022] [Indexed: 06/14/2023]
Abstract
Plastic waste is an emerging environmental issue for our society. Critical action to tackle this problem is to upcycle plastic waste as valuable feedstock. Thermochemical conversion of plastic waste has received growing attention. Although thermochemical conversion is promising for handling mixed plastic waste, it typically occurs at high temperatures (300-800 °C). Catalysts can play a critical role in improving the energy efficiency of thermochemical conversion, promoting targeted reactions, and improving product selectivity. This Review aims to summarize the state-of-the-art of catalytic thermochemical conversions of various types of plastic waste. First, general trends and recent development of catalytic thermochemical conversions including pyrolysis, gasification, hydrothermal processes, and chemolysis of plastic waste into fuels, chemicals, and value-added materials were reviewed. Second, the status quo for the commercial implementation of thermochemical conversion of plastic waste was summarized. Finally, the current challenges and future perspectives of catalytic thermochemical conversion of plastic waste including the design of sustainable and robust catalysts were discussed.
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Affiliation(s)
- Ren-Xuan Yang
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, MA 01851, USA
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10607, Taiwan
- Institute of Environmental Engineering and Management, National Taipei University of Technology, No.1 Sec. 3, Chung-Hsiao E. Rd., Taipei, 106344, Taiwan
| | - Kalsoom Jan
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, MA 01851, USA
| | - Ching-Tien Chen
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10607, Taiwan
| | - Wan-Ting Chen
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, MA 01851, USA
| | - Kevin C-W Wu
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10607, Taiwan
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16
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Berkner KL, Runge KW. Vitamin K-Dependent Protein Activation: Normal Gamma-Glutamyl Carboxylation and Disruption in Disease. Int J Mol Sci 2022; 23:5759. [PMID: 35628569 PMCID: PMC9146348 DOI: 10.3390/ijms23105759] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 12/12/2022] Open
Abstract
Vitamin K-dependent (VKD) proteins undergo an unusual post-translational modification, which is the conversion of specific Glu residues to carboxylated Glu (Gla). Gla generation is required for the activation of VKD proteins, and occurs in the endoplasmic reticulum during their secretion to either the cell surface or from the cell. The gamma-glutamyl carboxylase produces Gla using reduced vitamin K, which becomes oxygenated to vitamin K epoxide. Reduced vitamin K is then regenerated by a vitamin K oxidoreductase (VKORC1), and this interconversion of oxygenated and reduced vitamin K is referred to as the vitamin K cycle. Many of the VKD proteins support hemostasis, which is suppressed during therapy with warfarin that inhibits VKORC1 activity. VKD proteins also impact a broad range of physiologies beyond hemostasis, which includes regulation of calcification, apoptosis, complement, growth control, signal transduction and angiogenesis. The review covers the roles of VKD proteins, how they become activated, and how disruption of carboxylation can lead to disease. VKD proteins contain clusters of Gla residues that form a calcium-binding module important for activity, and carboxylase processivity allows the generation of multiple Glas. The review discusses how impaired carboxylase processivity results in the pseudoxanthoma elasticum-like disease.
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Affiliation(s)
- Kathleen L. Berkner
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at CWRU, Cleveland, OH 44195, USA
| | - Kurt W. Runge
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at CWRU, Cleveland, OH 44195, USA;
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17
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Ye TJ, Huang KF, Ko TP, Wu SH. Synergic action of an inserted carbohydrate-binding module in a glycoside hydrolase family 5 endoglucanase. Acta Crystallogr D Struct Biol 2022; 78:633-646. [PMID: 35503211 PMCID: PMC9063844 DOI: 10.1107/s2059798322002601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/07/2022] [Indexed: 11/24/2022] Open
Abstract
A unique endoglucanase with a carbohydrate-binding module inserted in the middle of the catalytic domain has been characterized structurally and functionally, providing insights into the mode of action responsible for its enhanced catalytic performance. Most known cellulase-associated carbohydrate-binding modules (CBMs) are attached to the N- or C-terminus of the enzyme or are expressed separately and assembled into multi-enzyme complexes (for example to form cellulosomes), rather than being an insertion into the catalytic domain. Here, by solving the crystal structure, it is shown that MtGlu5 from Meiothermus taiwanensis WR-220, a GH5-family endo-β-1,4-glucanase (EC 3.2.1.4), has a bipartite architecture consisting of a Cel5A-like catalytic domain with a (β/α)8 TIM-barrel fold and an inserted CBM29-like noncatalytic domain with a β-jelly-roll fold. Deletion of the CBM significantly reduced the catalytic efficiency of MtGlu5, as determined by isothermal titration calorimetry using inactive mutants of full-length and CBM-deleted MtGlu5 proteins. Conversely, insertion of the CBM from MtGlu5 into TmCel5A from Thermotoga maritima greatly enhanced the substrate affinity of TmCel5A. Bound sugars observed between two tryptophan side chains in the catalytic domains of active full-length and CBM-deleted MtGlu5 suggest an important stacking force. The synergistic action of the catalytic domain and CBM of MtGlu5 in binding to single-chain polysaccharides was visualized by substrate modeling, in which additional surface tryptophan residues were identified in a cross-domain groove. Subsequent site-specific mutagenesis results confirmed the pivotal role of several other tryptophan residues from both domains of MtGlu5 in substrate binding. These findings reveal a way to incorporate a CBM into the catalytic domain of an existing enzyme to make a robust cellulase.
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18
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Wu X, Tennakoon A, Yappert R, Esveld M, Ferrandon MS, Hackler RA, LaPointe AM, Heyden A, Delferro M, Peters B, Sadow AD, Huang W. Size-Controlled Nanoparticles Embedded in a Mesoporous Architecture Leading to Efficient and Selective Hydrogenolysis of Polyolefins. J Am Chem Soc 2022; 144:5323-5334. [PMID: 35195400 DOI: 10.1021/jacs.1c11694] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A catalytic architecture, comprising a mesoporous silica shell surrounding platinum nanoparticles (NPs) supported on a solid silica sphere (mSiO2/Pt-X/SiO2; X is the mean NP diameter), catalyzes hydrogenolysis of melt-phase polyethylene (PE) into a narrow C23-centered distribution of hydrocarbons in high yield using very low Pt loadings (∼10-5 g Pt/g PE). During catalysis, a polymer chain enters a pore and contacts a Pt NP where the C-C bond cleavage occurs and then the smaller fragment exits the pore. mSiO2/Pt/SiO2 resists sintering or leaching of Pt and provides high yields of liquids; however, many structural and chemical effects on catalysis are not yet resolved. Here, we report the effects of Pt NP size on activity and selectivity in PE hydrogenolysis. Time-dependent conversion and yields and a lumped kinetics model based on the competitive adsorption of long vs short chains reveal that the activity of catalytic material is highest with the smallest NPs, consistent with a structure-sensitive reaction. Remarkably, the three mSiO2/Pt-X/SiO2 catalysts give equivalent selectivity. We propose that mesoscale pores in the catalytic architecture template the C23-centered distribution, whereas the active Pt sites influence the carbon-carbon bond cleavage rate. This conclusion provides a framework for catalyst design by separating the C-C bond cleavage activity at catalytic sites from selectivity for chain lengths of the products influenced by the structure of the catalytic architecture. The increased activity, selectivity, efficiency, and lifetime obtained using this architecture highlight the benefits of localized and confined environments for isolated catalytic particles under condensed-phase reaction conditions.
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Affiliation(s)
- Xun Wu
- US DOE, Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Akalanka Tennakoon
- US DOE, Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Ryan Yappert
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Michaela Esveld
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Magali S Ferrandon
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ryan A Hackler
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Anne M LaPointe
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14583, United States
| | - Andreas Heyden
- Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Baron Peters
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Aaron D Sadow
- US DOE, Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Wenyu Huang
- US DOE, Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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19
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20
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Li S, Hsieh KY, Kuo CI, Su SC, Huang KF, Zhang K, Chang CI. Processive cleavage of substrate at individual proteolytic active sites of the Lon protease complex. SCIENCE ADVANCES 2021; 7:eabj9537. [PMID: 34757797 PMCID: PMC8580320 DOI: 10.1126/sciadv.abj9537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
The Lon protease is the prototype of a family of proteolytic machines with adenosine triphosphatase modules built into a substrate degradation chamber. Lon is known to degrade protein substrates in a processive fashion, cutting a protein chain processively into small peptides before commencing cleavages of another protein chain. Here, we present structural and biochemical evidence demonstrating that processive substrate degradation occurs at each of the six proteolytic active sites of Lon, which forms a deep groove that partially encloses the substrate polypeptide chain by accommodating only the unprimed residues and permits processive cleavage in the C-to-N direction. We identify a universally conserved acidic residue at the exit side of the binding groove indispensable for the proteolytic activity. This noncatalytic residue likely promotes processive proteolysis by carboxyl-carboxylate interactions with cleaved intermediates. Together, these results uncover a previously unrecognized mechanism for processive substrate degradation by the Lon protease.
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Affiliation(s)
- Shanshan Li
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale and Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Kan-Yen Hsieh
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Chiao-I Kuo
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shih-Chieh Su
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Kai-Fa Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Kaiming Zhang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale and Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Chung-I Chang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
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21
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22
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Gee CL, Holton JM, McPherson A. Structures of two novel crystal forms of Aspergillus oryzae alpha amylase (taka-amylase). J Biosci Bioeng 2021; 131:605-612. [PMID: 33814275 DOI: 10.1016/j.jbiosc.2021.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 01/22/2023]
Abstract
The structures of Aspergillus oryzae α-amylase were determined in a tetragonal crystal, having one molecule as asymmetric unit, and a monoclinic crystal with two molecules as asymmetric unit. Both crystal forms were obtained from trace contaminants of an old commercial lipase preparation. Structures were determined and refined to 1.65 Å and 1.43 Å resolution respectively. The latter crystal has a non-crystallographic (NCS) twofold axis within the asymmetric unit. Glycosylation at Asn197 is evident, and in the tetragonal crystal can be seen to include three, partially disordered sugar residues following the initial N-acetyl glucosamine (NAG). Superposition of the tetragonal crystal model on the α-amylases from Bacillus subtilis (PDB:1BAG), pig pancreas (PDB:3L2L), and barley (PDB:1AMY), show a high degree of coincidence, particularly for the (β/α)8-barrel domains, and especially within the active site. Using this structural agreement between amylases, we extrapolated the binding model of a six residue, limit dextrin found in pig pancreas α-amylase to the A. oryzae enzyme model, which predicts substrate interacting amino acid residues.
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Affiliation(s)
- Christine L Gee
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Stanley Hall 527, Berkeley, CA 94720-3220, USA
| | - James M Holton
- Department of Biochemistry and Biophysics, UC San Francisco, San Francisco, CA 94158, USA; Department of Molecular Biophysics and Integrated Bioimaging, Advanced Light Source, MS-2108, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Alexander McPherson
- Department of Molecular Biology and Biochemistry, University of California, 3205 McGaugh Hall, Irvine, CA 92697-3900, USA.
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23
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Kang JY, Llewellyn E, Chen J, Olinares PDB, Brewer J, Chait BT, Campbell EA, Darst SA. Structural basis for transcription complex disruption by the Mfd translocase. eLife 2021; 10:62117. [PMID: 33480355 PMCID: PMC7864632 DOI: 10.7554/elife.62117] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/21/2021] [Indexed: 12/30/2022] Open
Abstract
Transcription-coupled repair (TCR) is a sub-pathway of nucleotide excision repair (NER) that preferentially removes lesions from the template-strand (t-strand) that stall RNA polymerase (RNAP) elongation complexes (ECs). Mfd mediates TCR in bacteria by removing the stalled RNAP concealing the lesion and recruiting Uvr(A)BC. We used cryo-electron microscopy to visualize Mfd engaging with a stalled EC and attempting to dislodge the RNAP. We visualized seven distinct Mfd-EC complexes in both ATP and ADP-bound states. The structures explain how Mfd is remodeled from its repressed conformation, how the UvrA-interacting surface of Mfd is hidden during most of the remodeling process to prevent premature engagement with the NER pathway, how Mfd alters the RNAP conformation to facilitate disassembly, and how Mfd forms a processive translocation complex after dislodging the RNAP. Our results reveal an elaborate mechanism for how Mfd kinetically discriminates paused from stalled ECs and disassembles stalled ECs to initiate TCR.
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Affiliation(s)
- Jin Young Kang
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, United States
| | - Joshua Brewer
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, United States
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, United States
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Yakovlieva L, Ramírez-Palacios C, Marrink SJ, Walvoort MTC. Semiprocessive Hyperglycosylation of Adhesin by Bacterial Protein N-Glycosyltransferases. ACS Chem Biol 2021; 16:165-175. [PMID: 33401908 PMCID: PMC7812588 DOI: 10.1021/acschembio.0c00848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Processivity is an important feature
of enzyme families such as
DNA polymerases, polysaccharide synthases, and protein kinases, to
ensure high fidelity in biopolymer synthesis and modification. Here,
we reveal processive character in the family of cytoplasmic protein N-glycosyltransferases (NGTs). Through various activity
assays, intact protein mass spectrometry, and proteomics analysis,
we established that NGTs from nontypeable Haemophilus influenzae and Actinobacillus pleuropneumoniae modify an adhesin
protein fragment in a semiprocessive manner. Molecular modeling studies
suggest that the processivity arises from the shallow substrate binding
groove in NGT, which promotes the sliding of the adhesin over the
surface to allow further glycosylations without temporary dissociation.
We hypothesize that the processive character of these bacterial protein
glycosyltransferases is the mechanism to ensure multisite glycosylation
of adhesins in vivo, thereby creating the densely
glycosylated proteins necessary for bacterial self-aggregation and
adherence to human cells, as a first step toward infection.
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Affiliation(s)
- Liubov Yakovlieva
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Carlos Ramírez-Palacios
- Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Marthe T. C. Walvoort
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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25
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Irmscher T, Roske Y, Gayk I, Dunsing V, Chiantia S, Heinemann U, Barbirz S. Pantoea stewartii WceF is a glycan biofilm-modifying enzyme with a bacteriophage tailspike-like fold. J Biol Chem 2021; 296:100286. [PMID: 33450228 PMCID: PMC7949094 DOI: 10.1016/j.jbc.2021.100286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/22/2020] [Accepted: 01/11/2021] [Indexed: 11/19/2022] Open
Abstract
Pathogenic microorganisms often reside in glycan-based biofilms. Concentration and chain length distribution of these mostly anionic exopolysaccharides (EPS) determine the overall biophysical properties of a biofilm and result in a highly viscous environment. Bacterial communities regulate this biofilm state via intracellular small-molecule signaling to initiate EPS synthesis. Reorganization or degradation of this glycan matrix, however, requires the action of extracellular glycosidases. So far, these were mainly described for bacteriophages that must degrade biofilms for gaining access to host bacteria. The plant pathogen Pantoea stewartii (P. stewartii) encodes the protein WceF within its EPS synthesis cluster. WceF has homologs in various biofilm forming plant pathogens of the Erwinia family. In this work, we show that WceF is a glycosidase active on stewartan, the main P. stewartii EPS biofilm component. WceF has remarkable structural similarity with bacteriophage tailspike proteins (TSPs). Crystal structure analysis showed a native trimer of right-handed parallel β-helices. Despite its similar fold, WceF lacks the high stability found in bacteriophage TSPs. WceF is a stewartan hydrolase and produces oligosaccharides, corresponding to single stewartan repeat units. However, compared with a stewartan-specific glycan hydrolase of bacteriophage origin, WceF showed lectin-like autoagglutination with stewartan, resulting in notably slower EPS cleavage velocities. This emphasizes that the bacterial enzyme WceF has a role in P. stewartii biofilm glycan matrix reorganization clearly different from that of a bacteriophage exopolysaccharide depolymerase.
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Affiliation(s)
- Tobias Irmscher
- Physikalische Biochemie, Universität Potsdam, Potsdam, Germany; Department Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Yvette Roske
- Crystallography, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Igor Gayk
- Physikalische Biochemie, Universität Potsdam, Potsdam, Germany
| | - Valentin Dunsing
- Physikalische Zellbiochemie, Universität Potsdam, Potsdam, Germany
| | | | - Udo Heinemann
- Crystallography, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany; Institut für Chemie und Biochemie, Freie Universität, Berlin, Germany.
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26
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Tennakoon A, Wu X, Paterson AL, Patnaik S, Pei Y, LaPointe AM, Ammal SC, Hackler RA, Heyden A, Slowing II, Coates GW, Delferro M, Peters B, Huang W, Sadow AD, Perras FA. Catalytic upcycling of high-density polyethylene via a processive mechanism. Nat Catal 2020. [DOI: 10.1038/s41929-020-00519-4] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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27
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Murphy P, Xu Y, Rouse SL, Jaffray EG, Plechanovová A, Matthews SJ, Carlos Penedo J, Hay RT. Functional 3D architecture in an intrinsically disordered E3 ligase domain facilitates ubiquitin transfer. Nat Commun 2020; 11:3807. [PMID: 32733036 PMCID: PMC7393505 DOI: 10.1038/s41467-020-17647-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 07/13/2020] [Indexed: 12/18/2022] Open
Abstract
The human genome contains an estimated 600 ubiquitin E3 ligases, many of which are single-subunit E3s (ssE3s) that can bind to both substrate and ubiquitin-loaded E2 (E2~Ub). Within ssE3s structural disorder tends to be located in substrate binding and domain linking regions. RNF4 is a ssE3 ligase with a C-terminal RING domain and disordered N-terminal region containing SUMO Interactions Motifs (SIMs) required to bind SUMO modified substrates. Here we show that, although the N-terminal region of RNF4 bears no secondary structure, it maintains a compact global architecture primed for SUMO interaction. Segregated charged regions within the RNF4 N-terminus promote compaction, juxtaposing RING domain and SIMs to facilitate substrate ubiquitination. Mutations that induce a more extended shape reduce ubiquitination activity. Our result offer insight into a key step in substrate ubiquitination by a member of the largest ubiquitin ligase subtype and reveal how a defined architecture within a disordered region contributes to E3 ligase function.
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Affiliation(s)
- Paul Murphy
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH, Dundee, UK
| | - Yingqi Xu
- Centre for Structural Biology, Department of Life Sciences, Imperial College London, SW7 2AZ, London, UK
| | - Sarah L Rouse
- Centre for Structural Biology, Department of Life Sciences, Imperial College London, SW7 2AZ, London, UK
| | - Ellis G Jaffray
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH, Dundee, UK
| | - Anna Plechanovová
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH, Dundee, UK
| | - Steve J Matthews
- Centre for Structural Biology, Department of Life Sciences, Imperial College London, SW7 2AZ, London, UK
| | - J Carlos Penedo
- Centre of Biophotonics, School of Physics and Astronomy, University of St. Andrews, KY16 9SS, St. Andrews, UK
- Biomedical Sciences Research Complex, School of Biology, University of St. Andrews, KY16 9ST, St. Andrews, UK
| | - Ronald T Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, DD1 5EH, Dundee, UK.
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28
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Lin CC, Chen YP, Yang WZ, Shen JCK, Yuan H. Structural insights into CpG-specific DNA methylation by human DNA methyltransferase 3B. Nucleic Acids Res 2020; 48:3949-3961. [PMID: 32083663 PMCID: PMC7144912 DOI: 10.1093/nar/gkaa111] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/07/2020] [Accepted: 02/19/2020] [Indexed: 12/15/2022] Open
Abstract
DNA methyltransferases are primary enzymes for cytosine methylation at CpG sites of epigenetic gene regulation in mammals. De novo methyltransferases DNMT3A and DNMT3B create DNA methylation patterns during development, but how they differentially implement genomic DNA methylation patterns is poorly understood. Here, we report crystal structures of the catalytic domain of human DNMT3B-3L complex, noncovalently bound with and without DNA of different sequences. Human DNMT3B uses two flexible loops to enclose DNA and employs its catalytic loop to flip out the cytosine base. As opposed to DNMT3A, DNMT3B specifically recognizes DNA with CpGpG sites via residues Asn779 and Lys777 in its more stable and well-ordered target recognition domain loop to facilitate processive methylation of tandemly repeated CpG sites. We also identify a proton wire water channel for the final deprotonation step, revealing the complete working mechanism for cytosine methylation by DNMT3B and providing the structural basis for DNMT3B mutation-induced hypomethylation in immunodeficiency, centromere instability and facial anomalies syndrome.
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Affiliation(s)
- Chien-Chu Lin
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Ping Chen
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Wei-Zen Yang
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - James C K Shen
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Hanna S Yuan
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei 10048, Taiwan
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29
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Abstract
Extracellular polysaccharides and glycoproteins of pathogenic bacteria assist in adherence, autoaggregation, biofilm formation, and host immune system evasion. As a result, considerable research in the field of glycobiology is dedicated to study the composition and function of glycans associated with virulence, as well as the enzymes involved in their biosynthesis with the aim to identify novel antibiotic targets. Especially, insights into the enzyme mechanism, substrate binding, and transition-state structures are valuable as a starting point for rational inhibitor design. An intriguing aspect of enzymes that generate or process polysaccharides and glycoproteins is the level of processivity. The existence of enzymatic processivity reflects the need for regulation of the final glycan/glycoprotein length and structure, depending on the role they perform. In this Review, we describe the currently reported examples of various processive enzymes involved in polymerization and transfer of sugar moieties, predominantly in bacterial pathogens, with a focus on the biochemical methods, to showcase the importance of studying processivity for understanding the mechanism.
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Affiliation(s)
- Liubov Yakovlieva
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Marthe T. C. Walvoort
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
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30
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Molecular recognition in the product site of cellobiohydrolase Cel7A regulates processive step length. Biochem J 2020; 477:99-110. [PMID: 31816027 DOI: 10.1042/bcj20190770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 11/17/2022]
Abstract
Cellobiohydrolase Cel7A is an industrial important enzyme that breaks down cellulose by a complex processive mechanism. The enzyme threads the reducing end of a cellulose strand into its tunnel-shaped catalytic domain and progresses along the strand while sequentially releasing the disaccharide cellobiose. While some molecular details of this intricate process have emerged, general structure-function relationships for Cel7A remain poorly elucidated. One interesting aspect is the occurrence of particularly strong ligand interactions in the product binding site. In this work, we analyze these interactions in Cel7A from Trichoderma reesei with special emphasis on the Arg251 and Arg394 residues. We made extensive biochemical characterization of enzymes that were mutated in these two positions and showed that the arginine residues contributed strongly to product binding. Specifically, ∼50% of the total standard free energy of product binding could be ascribed to four hydrogen bonds to Arg251 and Arg394, which had previously been identified in crystal structures. Mutation of either Arg251 or Arg394 lowered production inhibition of Cel7A, but at the same time altered the enzyme product profile and resulted in ∼50% reduction in both processivity and hydrolytic activity. The position of the two arginine residues closely matches the two-fold screw axis symmetry of the substrate, and this energetically favors the productive enzyme-substrate complex. Our results indicate that the strong and specific ligand interactions of Arg251 and Arg394 provide a simple proofreading system that controls the step length during consecutive hydrolysis and minimizes dead time associated with transient, non-productive complexes.
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31
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Visootsat A, Nakamura A, Vignon P, Watanabe H, Uchihashi T, Iino R. Single-molecule imaging analysis reveals the mechanism of a high-catalytic-activity mutant of chitinase A from Serratia marcescens. J Biol Chem 2020; 295:1915-1925. [PMID: 31924658 PMCID: PMC7029130 DOI: 10.1074/jbc.ra119.012078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/03/2020] [Indexed: 12/17/2022] Open
Abstract
Chitin degradation is important for biomass conversion and has potential applications for agriculture, biotechnology, and the pharmaceutical industry. Chitinase A from the Gram-negative bacterium Serratia marcescens (SmChiA) is a processive enzyme that hydrolyzes crystalline chitin as it moves linearly along the substrate surface. In a previous study, the catalytic activity of SmChiA against crystalline chitin was found to increase after the tryptophan substitution of two phenylalanine residues (F232W and F396W), located at the entrance and exit of the substrate binding cleft of the catalytic domain, respectively. However, the mechanism underlying this high catalytic activity remains elusive. In this study, single-molecule fluorescence imaging and high-speed atomic force microscopy were applied to understand the mechanism of this high-catalytic-activity mutant. A reaction scheme including processive catalysis was used to reproduce the properties of SmChiA WT and F232W/F396W, in which all of the kinetic parameters were experimentally determined. High activity of F232W/F396W mutant was caused by a high processivity and a low dissociation rate constant after productive binding. The turnover numbers for both WT and F232W/F396W, determined by the biochemical analysis, were well-replicated using the kinetic parameters obtained from single-molecule imaging analysis, indicating the validity of the reaction scheme. Furthermore, alignment of amino acid sequences of 258 SmChiA-like proteins revealed that tryptophan, not phenylalanine, is the predominant amino acid at the corresponding positions (Phe-232 and Phe-396 for SmChiA). Our study will be helpful for understanding the kinetic mechanisms and further improvement of crystalline chitin hydrolytic activity of SmChiA mutants.
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Affiliation(s)
- Akasit Visootsat
- Department of Functional Molecular Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa 240-0193, Japan; Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Akihiko Nakamura
- Department of Functional Molecular Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa 240-0193, Japan; Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Paul Vignon
- Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Chimie ParisTech, Paris 75231, France
| | - Hiroki Watanabe
- Department of Physics, Nagoya University, Nagoya, Aichi 464-8601, Japan; Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute of Natural Science, Okazaki, Aichi 444-8787, Japan
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Nagoya, Aichi 464-8601, Japan; Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute of Natural Science, Okazaki, Aichi 444-8787, Japan
| | - Ryota Iino
- Department of Functional Molecular Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa 240-0193, Japan; Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.
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32
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Hamre AG, Sørlie M. Kinetic relationships with processivity in Serratia marcescens family 18 glycoside hydrolases. Biochem Biophys Res Commun 2020; 521:120-124. [PMID: 31629467 DOI: 10.1016/j.bbrc.2019.10.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 10/10/2019] [Indexed: 10/25/2022]
Abstract
In nature, recalcitrant polysaccharides such as chitin and cellulose are degraded by glycoside hydrolases (GH) that act synergistically through different modes of action including attack from reducing-end and nonreducing-end (exo-mode) and random (endo-mode) on single polysaccharide chains. Both modes can be combined with a processive mechanism where the GH remain bound to the polysaccharide to perform multiple catalytic steps before dissociation into the solution. In this work, we have determined association rate constants and their activation paramaters for three co-evolved GHs from Serratia marcescens (SmChiA, SmChiB, and SmChiC) with an oligomeric substrate. Interestingly, we observe a positive correlation between the association rate constants and processive ability for the GHs. Previously, a positive correlation has been observed between substrate binding affinity and processive ability. SmChiA with highest processive ability of the three GHs bind with a kon of 11.5 ± 0.2 μM-1s-1, which is five-fold and 130-fold faster than SmChiB (less processive) and SmChiC (nonprocessive), respectively.
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Affiliation(s)
- Anne Grethe Hamre
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, PO 5003, N-1432 Ås, Norway
| | - Morten Sørlie
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, PO 5003, N-1432 Ås, Norway.
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33
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Arnal G, Stogios PJ, Asohan J, Attia MA, Skarina T, Viborg AH, Henrissat B, Savchenko A, Brumer H. Substrate specificity, regiospecificity, and processivity in glycoside hydrolase family 74. J Biol Chem 2019; 294:13233-13247. [PMID: 31324716 DOI: 10.1074/jbc.ra119.009861] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/16/2019] [Indexed: 12/11/2022] Open
Abstract
Glycoside hydrolase family 74 (GH74) is a historically important family of endo-β-glucanases. On the basis of early reports of detectable activity on cellulose and soluble cellulose derivatives, GH74 was originally considered to be a "cellulase" family, although more recent studies have generally indicated a high specificity toward the ubiquitous plant cell wall matrix glycan xyloglucan. Previous studies have indicated that GH74 xyloglucanases differ in backbone cleavage regiospecificities and can adopt three distinct hydrolytic modes of action: exo, endo-dissociative, and endo-processive. To improve functional predictions within GH74, here we coupled in-depth biochemical characterization of 17 recombinant proteins with structural biology-based investigations in the context of a comprehensive molecular phylogeny, including all previously characterized family members. Elucidation of four new GH74 tertiary structures, as well as one distantly related dual seven-bladed β-propeller protein from a marine bacterium, highlighted key structure-function relationships along protein evolutionary trajectories. We could define five phylogenetic groups, which delineated the mode of action and the regiospecificity of GH74 members. At the extremes, a major group of enzymes diverged to hydrolyze the backbone of xyloglucan nonspecifically with a dissociative mode of action and relaxed backbone regiospecificity. In contrast, a sister group of GH74 enzymes has evolved a large hydrophobic platform comprising 10 subsites, which facilitates processivity. Overall, the findings of our study refine our understanding of catalysis in GH74, providing a framework for future experimentation as well as for bioinformatics predictions of sequences emerging from (meta)genomic studies.
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Affiliation(s)
- Gregory Arnal
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Jathavan Asohan
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Mohamed A Attia
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Alexander Holm Viborg
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix-Marseille University, 13007 Marseille, France; INRA, USC1408 Architecture et Fonction des Macromolécules Biologiques (AFMB), 13007 Marseille, France
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada; Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
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34
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Onizuka K, Miyashita T, Chikuni T, Ozawa M, Abe H, Nagatsugi F. Structural optimization of pseudorotaxane-forming oligonucleotides for efficient and stable complex formation. Nucleic Acids Res 2019; 46:8710-8719. [PMID: 30260454 PMCID: PMC6158610 DOI: 10.1093/nar/gky744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/06/2018] [Indexed: 01/15/2023] Open
Abstract
Interlocked structures, such as rotaxane and catenane, combine both static and dynamic properties. To expand their unique properties into the chemical biology field, a spontaneous formation method of the interlocked structures with the target would be ideal. We have previously developed a pseudorotaxane-forming oligo DNA (prfODN) to spontaneously form topological DNA/RNA architectures. In this study, we report the structural optimization of prfODNs for the efficient and stable complex formation. The optimized prfODNs efficiently formed pseudorotaxane structures with a DNA or RNA target, and the yield for the RNA target reached 85% in 5 min. In addition, the optimized prfODNs could form the pseudorotaxane structure with a smaller ring size and the structure significantly increased the kinetic stability. Furthermore, the catenane structure was successfully formed with the optimized prfODNs to provide the conclusive evidence for the formation of the threaded structure. This information will be valuable for developing new chemical methods using functional nucleic acids for antisense oligo nucleotides and DNA/RNA nanotechnology.
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Affiliation(s)
- Kazumitsu Onizuka
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Takuya Miyashita
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Tomoko Chikuni
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Mamiko Ozawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Hiroshi Abe
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Fumi Nagatsugi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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35
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Szabo B, Horvath T, Schad E, Murvai N, Tantos A, Kalmar L, Chemes LB, Han KH, Tompa P. Intrinsically Disordered Linkers Impart Processivity on Enzymes by Spatial Confinement of Binding Domains. Int J Mol Sci 2019; 20:ijms20092119. [PMID: 31032817 PMCID: PMC6540235 DOI: 10.3390/ijms20092119] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 12/14/2022] Open
Abstract
(1) Background: Processivity is common among enzymes and mechanochemical motors that synthesize, degrade, modify or move along polymeric substrates, such as DNA, RNA, polysaccharides or proteins. Processive enzymes can make multiple rounds of modification without releasing the substrate/partner, making their operation extremely effective and economical. The molecular mechanism of processivity is rather well understood in cases when the enzyme structurally confines the substrate, such as the DNA replication factor PCNA, and also when ATP energy is used to confine the succession of molecular events, such as with mechanochemical motors. Processivity may also result from the kinetic bias of binding imposed by spatial confinement of two binding elements connected by an intrinsically disordered (ID) linker. (2) Method: By statistical physical modeling, we show that this arrangement results in processive systems, in which the linker ensures an optimized effective concentration around novel binding site(s), favoring rebinding over full release of the polymeric partner. (3) Results: By analyzing 12 such proteins, such as cellulase, and RNAse-H, we illustrate that in these proteins linker length and flexibility, and the kinetic parameters of binding elements, are fine-tuned for optimizing processivity. We also report a conservation of structural disorder, special amino acid composition of linkers, and the correlation of their length with step size. (4) Conclusion: These observations suggest a unique type of entropic chain function of ID proteins, that may impart functional advantages on diverse enzymes in a variety of biological contexts.
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Affiliation(s)
- Beata Szabo
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Tamas Horvath
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Eva Schad
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Nikoletta Murvai
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Agnes Tantos
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Lajos Kalmar
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
| | - Lucía Beatriz Chemes
- Instituto de Investigaciones Biotecnológicas IIB-INTECH, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de San Martín, Buenos Aires 1650, Argentina.
| | - Kyou-Hoon Han
- Genome Editing Research Center, Division of Biomedical Science, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
- Department of Nano and Bioinformatics, University of Science and Technology (UST), Daejeon 34113, Korea.
| | - Peter Tompa
- Institute of Enzymology, Center of Natural Sciences, Hungarian Academy of Sciences, Budapest 1117, Hungary.
- VIB Center for Structural Biology, Vrije Univresiteit Brussel, 1050, Belgium.
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36
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Hamre AG, Kaupang A, Payne CM, Väljamäe P, Sørlie M. Thermodynamic Signatures of Substrate Binding for Three Thermobifida fusca Cellulases with Different Modes of Action. Biochemistry 2019; 58:1648-1659. [PMID: 30785271 DOI: 10.1021/acs.biochem.9b00014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The enzymatic breakdown of recalcitrant polysaccharides is achieved by synergistic enzyme cocktails of glycoside hydrolases (GHs) and accessory enzymes. Many GHs are processive, meaning that they stay bound to the substrate between subsequent catalytic interactions. Cellulases are GHs that catalyze the hydrolysis of cellulose [β-1,4-linked glucose (Glc)]. Here, we have determined the relative subsite binding affinity for a glucose moiety as well as the thermodynamic signatures for (Glc)6 binding to three of the seven cellulases produced by the bacterium Thermobifida fusca. TfCel48A is exo-processive, TfCel9A endo-processive, and TfCel5A endo-nonprocessive. Initial hydrolysis of (Glc)5 and (Glc)6 was performed in H218O enabling the incorporation of an 18O atom at the new reducing end anomeric carbon. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the products reveals the intensity ratios of otherwise identical 18O- and 16O-containing products to provide insight into how the substrate is placed during productive binding. The two processive cellulases have significant binding affinity in subsites where products dissociate during processive hydrolysis, aligned with a need to have a pushing potential to remove obstacles on the substrate. Moreover, we observed a correlation between processive ability and favorable binding free energy, as previously postulated. Upon ligand binding, the largest contribution to the binding free energy is desolvation for all three cellulases as determined by isothermal titration calorimetry. The two endo-active cellulases show a more favorable solvation entropy change compared to the exo-active cellulase, while the two processive cellulases have less favorable changes in binding enthalpy compared to the nonprocessive TfCel5A.
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Affiliation(s)
- Anne Grethe Hamre
- Department of Chemistry, Biotechnology and Food Science , Norwegian University of Life Sciences , P.O. Box 5003, N-1432 Ås , Norway
| | - Anita Kaupang
- Department of Chemistry, Biotechnology and Food Science , Norwegian University of Life Sciences , P.O. Box 5003, N-1432 Ås , Norway
| | - Christina M Payne
- Department of Chemical and Materials Engineering , University of Kentucky , 177 F. Paul Anderson Tower , Lexington , Kentucky 40506 , United States
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology , University of Tartu , 50090 Tartu , Estonia
| | - Morten Sørlie
- Department of Chemistry, Biotechnology and Food Science , Norwegian University of Life Sciences , P.O. Box 5003, N-1432 Ås , Norway
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37
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Jeng WY, Liu CI, Lu TJ, Lin HJ, Wang NC, Wang AHJ. Crystal Structures of the C-Terminally Truncated Endoglucanase Cel9Q from Clostridium thermocellum Complexed with Cellodextrins and Tris. Chembiochem 2019; 20:295-307. [PMID: 30609216 DOI: 10.1002/cbic.201800789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Indexed: 11/11/2022]
Abstract
Endoglucanase CtCel9Q is one of the enzyme components of the cellulosome, which is an active cellulase system in the thermophile Clostridium thermocellum. The precursor form of CtCel9Q comprises a signal peptide, a glycoside hydrolase family 9 catalytic domain, a type 3c carbohydrate-binding module (CBM), and a type I dockerin domain. Here, we report the crystal structures of C-terminally truncated CtCel9Q (CtCel9QΔc) complexed with Tris, Tris+cellobiose, cellobiose+cellotriose, cellotriose, and cellotetraose at resolutions of 1.50, 1.70, 2.05, 2.05 and 1.75 Å, respectively. CtCel9QΔc forms a V-shaped homodimer through residues Lys529-Glu542 on the type 3c CBM, which pairs two β-strands (β4 and β5 of the CBM). In addition, a disulfide bond was formed between the two Cys535 residues of the protein monomers in the asymmetric unit. The structures allow the identification of four minus (-) subsites and two plus (+) subsites; this is important for further understanding the structural basis of cellulose binding and hydrolysis. In the oligosaccharide-free and cellobiose-bound CtCel9QΔc structures, a Tris molecule was found to be bound to three catalytic residues of CtCel9Q and occupied subsite -1 of the CtCel9Q active-site cleft. Moreover, the enzyme activity assay in the presence of 100 mm Tris showed that the Tris almost completely suppressed CtCel9Q hydrolase activity.
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Affiliation(s)
- Wen-Yih Jeng
- University Center for Bioscience and Biotechnology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan.,Department of Biochemistry and Molecular Biology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan
| | - Chia-I Liu
- School of Medical Laboratory Science and Biotechnology, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
| | - Te-Jung Lu
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, 89 Wenhua 1st Street, Tainan, 717, Taiwan
| | - Hong-Jie Lin
- University Center for Bioscience and Biotechnology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan
| | - Nai-Chen Wang
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Sec. 2, Taipei, 115, Taiwan
| | - Andrew H-J Wang
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Sec 2, Taipei, 115, Taiwan
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38
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Petrášek Z, Eibinger M, Nidetzky B. Modeling the activity burst in the initial phase of cellulose hydrolysis by the processive cellobiohydrolase Cel7A. Biotechnol Bioeng 2019; 116:515-525. [PMID: 30515756 PMCID: PMC6590443 DOI: 10.1002/bit.26889] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/16/2018] [Accepted: 11/29/2018] [Indexed: 01/05/2023]
Abstract
The hydrolysis of cellulose by processive cellulases, such as exocellulase TrCel7A from Trichoderma reesei, is typically characterized by an initial burst of high activity followed by a slowdown, often leading to incomplete hydrolysis of the substrate. The origins of these limitations to cellulose hydrolysis are not yet fully understood. Here, we propose a new model for the initial phase of cellulose hydrolysis by processive cellulases, incorporating a bound but inactive enzyme state. The model, based on ordinary differential equations, accurately reproduces the activity burst and the subsequent slowdown of the cellulose hydrolysis and describes the experimental data equally well or better than the previously suggested model. We also derive steady‐state expressions that can be used to describe the pseudo‐steady state reached after the initial activity burst. Importantly, we show that the new model predicts the existence of an optimal enzyme‐substrate affinity at which the pseudo‐steady state hydrolysis rate is maximized. The model further allows the calculation of glucose production rate from the first cut in the processive run and reproduces the second activity burst commonly observed upon new enzyme addition. These results are expected to be applicable also to other processive enzymes.
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Affiliation(s)
- Zdeneˇk Petrášek
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Manuel Eibinger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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39
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Amos RA, Mohnen D. Critical Review of Plant Cell Wall Matrix Polysaccharide Glycosyltransferase Activities Verified by Heterologous Protein Expression. FRONTIERS IN PLANT SCIENCE 2019; 10:915. [PMID: 31379900 PMCID: PMC6646851 DOI: 10.3389/fpls.2019.00915] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/27/2019] [Indexed: 05/02/2023]
Abstract
The life cycle and development of plants requires the biosynthesis, deposition, and degradation of cell wall matrix polysaccharides. The structures of the diverse cell wall matrix polysaccharides influence commercially important properties of plant cells, including growth, biomass recalcitrance, organ abscission, and the shelf life of fruits. This review is a comprehensive summary of the matrix polysaccharide glycosyltransferase (GT) activities that have been verified using in vitro assays following heterologous GT protein expression. Plant cell wall (PCW) biosynthetic GTs are primarily integral transmembrane proteins localized to the endoplasmic reticulum and Golgi of the plant secretory system. The low abundance of these enzymes in plant tissues makes them particularly difficult to purify from native plant membranes in quantities sufficient for enzymatic characterization, which is essential to study the functions of the different GTs. Numerous activities in the synthesis of the major cell wall matrix glycans, including pectins, xylans, xyloglucan, mannans, mixed-linkage glucans (MLGs), and arabinogalactan components of AGP proteoglycans have been mapped to specific genes and multi-gene families. Cell wall GTs include those that synthesize the polymer backbones, those that elongate side branches with extended glycosyl chains, and those that add single monosaccharide linkages onto polysaccharide backbones and/or side branches. Three main strategies have been used to identify genes encoding GTs that synthesize cell wall linkages: analysis of membrane fractions enriched for cell wall biosynthetic activities, mutational genetics approaches investigating cell wall compositional phenotypes, and omics-directed identification of putative GTs from sequenced plant genomes. Here we compare the heterologous expression systems used to produce, purify, and study the enzyme activities of PCW GTs, with an emphasis on the eukaryotic systems Nicotiana benthamiana, Pichia pastoris, and human embryonic kidney (HEK293) cells. We discuss the enzymatic properties of GTs including kinetic rates, the chain lengths of polysaccharide products, acceptor oligosaccharide preferences, elongation mechanisms for the synthesis of long-chain polymers, and the formation of GT complexes. Future directions in the study of matrix polysaccharide biosynthesis are proposed.
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Affiliation(s)
- Robert A. Amos
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Debra Mohnen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- *Correspondence: Debra Mohnen
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40
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Wang Z, Zhang T, Long L, Ding S. Altering the linker in processive GH5 endoglucanase 1 modulates lignin binding and catalytic properties. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:332. [PMID: 30568732 PMCID: PMC6297974 DOI: 10.1186/s13068-018-1333-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/07/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The non-productive adsorption of cellulases onto lignin in biomass is a key issue for the biofuel process economy. It would be helpful to reduce the inhibitory effect of lignin on enzymatic hydrolysis by engineering weak lignin-binding cellulases. Cellulase linkers are highly divergent in their lengths, compositions, and glycosylations. Numerous studies have revealed that linkers can facilitate optimal interactions between structured domains. Recently, efforts have focused on the contributions and mechanisms of carbohydrate-binding modules and catalytic domains that affect lignin affinity and processivity of cellulases, but our understanding of the effects of the linker regions on lignin adsorption and processivity of GH5 processive endoglucanases is still limited. RESULTS Eight GH5 endoglucanase 1 variants of varying length, flexibility, and sequence in the linker region were constructed. Their characteristics were then compared to the wild-type enzyme (EG1). Remarkably, significant differences in the lignin adsorption profiles and processivities were observed for EG1 and other variants. Our studies suggest that either the length or the specific amino acid composition of the linker has a prominent influence on the lignin-binding affinity of the enzymes. Comparatively, the processivity may depend primarily on the length of the linker and less so on the specific amino acid composition. EG1-ApCel5A, a variant with better performance in enzymatic hydrolysis in the presence of lignin, was obtained by replacing a longer, flexible linker. In total, up to between 28.2 and 30.1% more reducing sugars were generated from filter paper by EG1-ApCel5A in the presence of lignin compared to EG1. CONCLUSIONS Our results highlight the relevance of the linker region in the lignin adsorption and processivity of a processive endoglucanase. Our findings suggest that the linker region may be used as a target for the design of more active and weaker lignin-binding cellulases.
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Affiliation(s)
- Zhen Wang
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu China
| | - Tianrui Zhang
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu China
| | - Liangkun Long
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu China
| | - Shaojun Ding
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu China
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41
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Amos RA, Pattathil S, Yang JY, Atmodjo MA, Urbanowicz BR, Moremen KW, Mohnen D. A two-phase model for the non-processive biosynthesis of homogalacturonan polysaccharides by the GAUT1:GAUT7 complex. J Biol Chem 2018; 293:19047-19063. [PMID: 30327429 DOI: 10.1074/jbc.ra118.004463] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/08/2018] [Indexed: 11/06/2022] Open
Abstract
Homogalacturonan (HG) is a pectic glycan in the plant cell wall that contributes to plant growth and development and cell wall structure and function, and interacts with other glycans and proteoglycans in the wall. HG is synthesized by the galacturonosyltransferase (GAUT) gene family. Two members of this family, GAUT1 and GAUT7, form a heteromeric enzyme complex in Arabidopsis thaliana Here, we established a heterologous GAUT expression system in HEK293 cells and show that co-expression of recombinant GAUT1 with GAUT7 results in the production of a soluble GAUT1:GAUT7 complex that catalyzes elongation of HG products in vitro The reaction rates, progress curves, and product distributions exhibited major differences dependent upon small changes in the degree of polymerization (DP) of the oligosaccharide acceptor. GAUT1:GAUT7 displayed >45-fold increased catalytic efficiency with DP11 acceptors relative to DP7 acceptors. Although GAUT1:GAUT7 synthesized high-molecular-weight polymeric HG (>100 kDa) in a substrate concentration-dependent manner typical of distributive (nonprocessive) glycosyltransferases with DP11 acceptors, reactions primed with short-chain acceptors resulted in a bimodal product distribution of glycan products that has previously been reported as evidence for a processive model of GT elongation. As an alternative to the processive glycosyltransfer model, a two-phase distributive elongation model is proposed in which a slow phase, which includes the de novo initiation of HG and elongation of short-chain acceptors, is distinguished from a phase of rapid elongation of intermediate- and long-chain acceptors. Upon reaching a critical chain length of DP11, GAUT1:GAUT7 elongates HG to high-molecular-weight products.
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Affiliation(s)
- Robert A Amos
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | | | | | - Melani A Atmodjo
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | | | - Kelley W Moremen
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | - Debra Mohnen
- From the Complex Carbohydrate Research Center and .,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
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42
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Lyu Q, Zhang K, Zhu Q, Li Z, Liu Y, Fitzek E, Yohe T, Zhao L, Li W, Liu T, Yin Y, Liu W. Structural and biochemical characterization of a multidomain alginate lyase reveals a novel role of CBM32 in CAZymes. Biochim Biophys Acta Gen Subj 2018; 1862:1862-1869. [DOI: 10.1016/j.bbagen.2018.05.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 01/27/2023]
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43
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Qing Y, Ionescu SA, Pulcu GS, Bayley H. Directional control of a processive molecular hopper. Science 2018; 361:908-912. [DOI: 10.1126/science.aat3872] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 06/21/2018] [Indexed: 01/08/2023]
Abstract
Intrigued by the potential of nanoscale machines, scientists have long attempted to control molecular motion. We monitored the individual 0.7-nanometer steps of a single molecular hopper as it moved in an electric field along a track in a nanopore controlled by a chemical ratchet. The hopper demonstrated characteristics desired in a moving molecule: defined start and end points, processivity, no chemical fuel requirement, directional motion, and external control. The hopper was readily functionalized to carry cargos. For example, a DNA molecule could be ratcheted along the track in either direction, a prerequisite for nanopore sequencing.
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44
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Vijayaraghavan J, Kumar V, Krishnan NP, Kaufhold RT, Zeng X, Lin J, van den Akker F. Structural studies and molecular dynamics simulations suggest a processive mechanism of exolytic lytic transglycosylase from Campylobacter jejuni. PLoS One 2018; 13:e0197136. [PMID: 29758058 PMCID: PMC5951611 DOI: 10.1371/journal.pone.0197136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/26/2018] [Indexed: 11/21/2022] Open
Abstract
The bacterial soluble lytic transglycosylase (LT) breaks down the peptidoglycan (PG) layer during processes such as cell division. We present here crystal structures of the soluble LT Cj0843 from Campylobacter jejuni with and without bulgecin A inhibitor in the active site. Cj0843 has a doughnut shape similar but not identical to that of E. coli SLT70. The C-terminal catalytic domain is preceded by an L-domain, a large helical U-domain, a flexible linker, and a small N-terminal NU-domain. The flexible linker allows the NU-domain to reach over and complete the circular shape, using residues conserved in the Epsilonproteobacteria LT family. The inner surface of the Cj0843 doughnut is mostly positively charged including a pocket that has 8 Arg/Lys residues. Molecular dynamics simulations with PG strands revealed a potential functional role for this pocket in anchoring the negatively charged terminal tetrapeptide of the PG during several steps in the reaction including homing and aligning the PG strand for exolytic cleavage, and subsequent ratcheting of the PG strand to enhance processivity in degrading PG strands.
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Affiliation(s)
- Jagamya Vijayaraghavan
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Vijay Kumar
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Nikhil P. Krishnan
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Ross T. Kaufhold
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Ximin Zeng
- Institute of agriculture, University of Tennessee, Knoxville, TN, United States of America
| | - Jun Lin
- Institute of agriculture, University of Tennessee, Knoxville, TN, United States of America
| | - Focco van den Akker
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
- * E-mail:
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45
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van Dongen SFM, Clerx J, van den Boomen OI, Pervaiz M, Trakselis MA, Ritschel T, Schoonen L, Schoenmakers DC, Nolte RJM. Synthetic polymers as substrates for a DNA-sliding clamp protein. Biopolymers 2018; 109:e23119. [PMID: 29700825 PMCID: PMC6001473 DOI: 10.1002/bip.23119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 11/08/2022]
Abstract
The clamp protein (gp45) of the DNA polymerase III of the bacteriophage T4 is known to bind to DNA and stay attached to it in order to facilitate the process of DNA copying by the polymerase. As part of a project aimed at developing new biomimetic data-encoding systems we have investigated the binding of gp45 to synthetic polymers, that is, rigid, helical polyisocyanopeptides. Molecular modelling studies suggest that the clamp protein may interact with the latter polymers. Experiments aimed at verifying these interactions are presented and discussed.
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Affiliation(s)
- S. F. M. van Dongen
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
| | - J. Clerx
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
| | - O. I. van den Boomen
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
| | - M. Pervaiz
- Center for Molecular and Biomolecular Informatics (CMBI). Radboud University Medical Center, Geert Grooteplein Zuid 26‐28NijmegenHB6500The Netherlands
| | - M. A. Trakselis
- Baylor University, Department of Chemistry and Biochemistry, One Bear Place #97348WacoTexas76798‐7348
| | - T. Ritschel
- Center for Molecular and Biomolecular Informatics (CMBI). Radboud University Medical Center, Geert Grooteplein Zuid 26‐28NijmegenHB6500The Netherlands
| | - L. Schoonen
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
| | - D. C. Schoenmakers
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
| | - R. J. M. Nolte
- Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135Nijmegen6525AJThe Netherlands
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46
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Zhang KD, Li W, Wang YF, Zheng YL, Tan FC, Ma XQ, Yao LS, Bayer EA, Wang LS, Li FL. Processive Degradation of Crystalline Cellulose by a Multimodular Endoglucanase via a Wirewalking Mode. Biomacromolecules 2018; 19:1686-1696. [DOI: 10.1021/acs.biomac.8b00340] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kun-Di Zhang
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, People’s Republic of China
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People’s Republic of China
| | - Wen Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People’s Republic of China
| | - Ye-Fei Wang
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, People’s Republic of China
| | - Yan-Lin Zheng
- College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, 266590, People’s Republic of China
| | - Fang-Cheng Tan
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, People’s Republic of China
| | - Xiao-Qing Ma
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, People’s Republic of China
| | - Li-Shan Yao
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, People’s Republic of China
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Lu-Shan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People’s Republic of China
| | - Fu-Li Li
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, People’s Republic of China
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47
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van Dijk L, Tilby MJ, Szpera R, Smith OA, Bunce HAP, Fletcher SP. Molecular machines for catalysis. Nat Rev Chem 2018. [DOI: 10.1038/s41570-018-0117] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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48
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Zhao Y, Chi Z, Xu Y, Shi N, Chi Z, Liu G. High-level extracellular expression of κ-carrageenase in Brevibacillus choshinensis for the production of a series of κ-carrageenan oligosaccharides. Process Biochem 2018. [DOI: 10.1016/j.procbio.2017.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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49
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Fiebig T, Litschko C, Freiberger F, Bethe A, Berger M, Gerardy-Schahn R. Efficient solid-phase synthesis of meningococcal capsular oligosaccharides enables simple and fast chemoenzymatic vaccine production. J Biol Chem 2017; 293:953-962. [PMID: 29187601 DOI: 10.1074/jbc.ra117.000488] [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: 10/17/2017] [Revised: 11/28/2017] [Indexed: 12/22/2022] Open
Abstract
Neisseria meningitidis serogroups A and X are among the leading causes of bacterial meningitis in the African meningitis belt. Glycoconjugate vaccines, consisting of an antigenic carrier protein coupled to the capsular polysaccharide of the bacterial pathogen, are the most effective strategy for prevention of meningococcal disease. However, the distribution of effective glycoconjugate vaccines in this region is limited by the high cost of cultivating pathogens and purification of their capsular polysaccharides. Moreover, chemical approaches to synthesize oligosaccharide antigens have proven challenging. In the current study, we present a chemoenzymatic approach for generating tailored oligosaccharide fractions ready for activation and coupling to the carrier protein. In a first step, the elongation modes of recombinant capsular polymerases from Neisseria meningitidis serogroups A (CsaB) and X (CsxA) were characterized. We observed that CsaB is a distributive enzyme, and CsxA is a processive enzyme. Sequence comparison of these two stealth family proteins revealed a C-terminal extension in CsxA, which conferred processivity because of the existence of a second product-binding site. Deletion of the C-terminal domain converted CsxA into a distributive enzyme, allowing facile control of product length by adjusting the ratio of donor to acceptor sugars. Solid-phase fixation of the engineered capsular polymerases enabled rapid production of capsular polysaccharides with high yield and purity. In summary, the tools developed here provide critical steps toward reducing the cost of conjugate vaccine production, which will increase access in regions with the greatest need. Our work also facilitates efforts to study the relationship between oligosaccharide size and antigenicity.
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Affiliation(s)
- Timm Fiebig
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Christa Litschko
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Friedrich Freiberger
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Andrea Bethe
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Monika Berger
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Rita Gerardy-Schahn
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
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50
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Alanine substitution in cellobiohydrolase provides new insights into substrate threading. Sci Rep 2017; 7:16320. [PMID: 29176588 PMCID: PMC5701224 DOI: 10.1038/s41598-017-16434-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 11/13/2017] [Indexed: 12/14/2022] Open
Abstract
The glycoside hydrolase family 7 (GH7) member cellobiohydrolase (CBH) is a key enzyme that degrades crystalline cellulose, an important structural component of plant cell walls. As GH7 CBH is a major component in the enzyme mixture used to degrade biomass into fermentable glucose in biorefineries, enhancing its catalytic activity will significantly impact development in this field. GH7 CBH possesses a catalytic tunnel through which cellulose substrates are threaded and hydrolysed. Despite numerous studies dissecting this processive mechanism, the role of amino acid residues in the tunnel remains not fully understood. Herein, we examined the respective contributions of nine amino acid residues in the catalytic tunnel of GH7 CBH from Talaromyces cellulolyticus by substitution with alanine. As a result, N62A and K203A mutants were found to possess significantly higher cellulase activities than wild type. Molecular dynamics simulations showed that the N62 residue interacted strongly with the cellulose substrate, impeding threading, while the N62A mutant allowed cellulose to proceed more smoothly. Furthermore, the W63 residue was observed to facilitate twisting of the cellulose substrate in our simulations. This study helps elucidate cellulose threading and provides insight into biomass hydrolysis.
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