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Gabay M, Stern I, Gruzdev N, Cohen A, Adriana-Lifshits L, Ansbacher T, Yadid I, Gal M. Engineering of methionine-auxotroph Escherichia coli via parallel evolution of two enzymes from Corynebacterium glutamicum's direct-sulfurylation pathway enables its recovery in minimal medium. Metab Eng Commun 2024; 18:e00236. [PMID: 38779352 PMCID: PMC11109467 DOI: 10.1016/j.mec.2024.e00236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/18/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
Methionine biosynthesis relies on the sequential catalysis of multiple enzymes. Escherichia coli, the main bacteria used in research and industry for protein production and engineering, utilizes the three-step trans-sulfurylation pathway catalyzed by L-homoserine O-succinyl transferase, cystathionine gamma synthase and cystathionine beta lyase to convert L-homoserine to L-homocysteine. However, most bacteria employ the two-step direct-sulfurylation pathway involving L-homoserine O-acetyltransferases and O-acetyl homoserine sulfhydrylase. We previously showed that a methionine-auxotroph Escherichiacoli strain (MG1655) with deletion of metA, encoding for L-homoserine O-succinyl transferase, and metB, encoding for cystathionine gamma synthase, could be complemented by introducing the genes metX, encoding for L-homoserine O-acetyltransferases and metY, encoding for O-acetyl homoserine sulfhydrylase, from various sources, thus altering the Escherichia coli methionine biosynthesis metabolic pathway to direct-sulfurylation. However, introducing metX and metY from Corynebacterium glutamicum failed to complement methionine auxotrophy. Herein, we generated a randomized genetic library based on the metX and metY of Corynebacterium glutamicum and transformed it into a methionine-auxotrophic Escherichia coli strain lacking the metA and metB genes. Through multiple enrichment cycles, we successfully isolated active clones capable of growing in M9 minimal media. The dominant metX mutations in the evolved methionine-autotrophs Escherichia coli were L315P and H46R. Interestingly, we found that a metY gene encoding only the N-terminus 106 out of 438 amino acids of the wild-type MetY enzyme is functional and supports the growth of the methionine auxotroph. Recloning the new genes into the original plasmid and transforming them to methionine auxotroph Escherichia coli validated their functionality. These results show that directed enzyme-evolution enables fast and simultaneous engineering of new active variants within the Escherichia coli methionine direct-sulfurylation pathway, leading to efficient complementation.
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Affiliation(s)
- Matan Gabay
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Inbar Stern
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Nadya Gruzdev
- Migal - Galilee Research Institute, Kiryat Shmona, 11016, Israel
| | - Adi Cohen
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Lucia Adriana-Lifshits
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Tamar Ansbacher
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
- Hadassah Academic College, 91010, Jerusalem, Israel
| | - Itamar Yadid
- Migal - Galilee Research Institute, Kiryat Shmona, 11016, Israel
- Tel-Hai College, Upper Galilee, 1220800, Israel
| | - Maayan Gal
- Department of Oral Biology, Goldschleger School of Dental Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
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Lv Z, Wang Z, Wu S, Yu X. Enhanced catalytic performance of penicillin G acylase by covalent immobilization onto functionally-modified magnetic Ni0.4Cu0.5Zn0.1Fe2O4 nanoparticles. PLoS One 2024; 19:e0297149. [PMID: 38241311 PMCID: PMC10798532 DOI: 10.1371/journal.pone.0297149] [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: 09/06/2023] [Accepted: 12/28/2023] [Indexed: 01/21/2024] Open
Abstract
With the emergence of penicillin resistance, the development of novel antibiotics has become an urgent necessity. Semi-synthetic penicillin has emerged as a promising alternative to traditional penicillin. The demand for the crucial intermediate, 6-aminopicillanic acid (6-APA), is on the rise. Enzyme catalysis is the primary method employed for its production. However, due to certain limitations, the strategy of enzyme immobilization has also gained prominence. The magnetic Ni0.4Cu0.5Zn0.1Fe2O4 nanoparticles were successfully prepared by a rapid-combustion method. Sodium silicate was used to modify the surface of the Ni0.4Cu0.5Zn0.1Fe2O4 nanoparticles to obtain silica-coated nanoparticles (Ni0.4Cu0.5Zn0.1Fe2O4-SiO2). Subsequently, in order to better crosslink PGA, the nanoparticles were modified again with glutaraldehyde to obtain glutaraldehyde crosslinked Ni0.4Cu0.5Zn0.1Fe2O4-SiO2-GA nanoparticles which could immobilize the PGA. The structure of the PGA protein was analyzed by the PyMol program and the immobilization strategy was determined. The conditions of PGA immobilization were investigated, including immobilization time and PGA concentration. Finally, the enzymological properties of the immobilized and free PGA were compared. The optimum catalytic pH of immobilized and free PGA was 8.0, and the optimum catalytic temperature of immobilized PGA was 50°C, 5°C higher than that of free PGA. Immobilized PGA in a certain pH and temperature range showed better catalytic stability. Vmax and Km of immobilized PGA were 0.3727 μmol·min-1 and 0.0436 mol·L-1, and the corresponding free PGA were 0.7325 μmol·min-1 and 0.0227 mol·L-1. After five cycles, the immobilized enzyme activity was still higher than 25%.
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Affiliation(s)
- Zhixiang Lv
- The People’s Hospital of Danyang, Affiliated Danyang Hospital of Nantong University, Zhenjiang, 212300, P.R. China
| | - Zhou Wang
- Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province, College of Vanadium and Titanium, Panzhihua University, Panzhihua, 617000, P.R. China
| | - Shaobo Wu
- Zhenjiang Hospital of Chinese Traditional and Western Medicine, Zhenjiang, 212013, P.R. China
| | - Xiang Yu
- Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province, College of Vanadium and Titanium, Panzhihua University, Panzhihua, 617000, P.R. China
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Loch JI, Ściuk A, Kilichowska M, Pieróg I, Łukaszczyk W, Zimowska K, Jaskolski M. Probing the enzymatic activity and maturation process of the EcAIII Ntn-amidohydrolase using local random mutagenesis. Acta Biochim Pol 2024; 71:12299. [PMID: 38721302 PMCID: PMC11077353 DOI: 10.3389/abp.2024.12299] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/05/2024] [Indexed: 05/15/2024]
Abstract
This report describes a comprehensive approach to local random mutagenesis of the E. coli Ntn-amidohydrolase EcAIII, and supplements the results published earlier for the randomization series RDM1. Here, random mutagenesis was applied in the center of the EcAIII molecule, i.e., in the region important for substrate binding and its immediate neighborhood (series RDM2, RDM3, RDM7), in the vicinity of the catalytic threonine triplet (series RDM4, RDM5, RDM6), in the linker region (series RDM8), and in the sodium-binding (stabilization) loop (series RDM9). The results revealed that the majority of the new EcAIII variants have abolished or significantly reduced rate of autoprocessing, even if the mutation was not in a highly conserved sequence and structure regions. AlphaFold-predicted structures of the mutants suggest the role of selected residues in the positioning of the linker and stabilization of the scissile bond in precisely correct orientation, enabling the nucleophilic attack during the maturation process. The presented data highlight the details of EcAIII geometry that are important for the autoproteolytic maturation and for the catalytic mechanism in general, and can be treated as a guide for protein engineering experiments with other Ntn-hydrolases.
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Affiliation(s)
- Joanna I. Loch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Anna Ściuk
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, Krakow, Poland
| | - Marta Kilichowska
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, Krakow, Poland
| | - Izabela Pieróg
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, Krakow, Poland
| | - Weronika Łukaszczyk
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Katarzyna Zimowska
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Mariusz Jaskolski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- Department of Crystallography, Faculty of Chemistry, Adam Mickiewicz University, Poznan, Poland
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Li J, Wang S, Miao Y, Wan Y, Li C, Wang Y. Mining and modification of Oryza sativa-derived squalene epoxidase for improved β-amyrin production in Saccharomyces cerevisiae. J Biotechnol 2023; 375:1-11. [PMID: 37597655 DOI: 10.1016/j.jbiotec.2023.08.004] [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] [Received: 03/07/2023] [Revised: 07/13/2023] [Accepted: 08/14/2023] [Indexed: 08/21/2023]
Abstract
β-Amyrin is a pentacyclic triterpenoid and has anti-viral, anti-bacterial and anti-inflammatory activities. The synthetic pathway of β-amyrin has been analyzed and its heterogeneous synthesis has been achieved in Saccharomyces cerevisiae. Squalene epoxidase (SQE) catalyzes the oxygenation of squalene to form 2,3-oxidosqualene and is rate-limiting in the synthetic pathways of β-amyrin. The endogenous SQE in S. cerevisiae is insufficient for high production of β-amyrin. Herein, eight squalene epoxidases derived from different plants were selected and characterized in S. cerevisiae for improved biosynthesis of β-amyrin. Among them, the squalene epoxidase from Oryza sativa (OsSQE52) showed the best performance compared to other plant-derived sources. Through protein remodeling, the mutant OsSQE52L256R, obtained based on modeling analysis, increased the titer of β-amyrin by 2.43-fold compared to that in the control strain with ERG1 overexpressed under the same conditions. Moreover, the expression of OsSQE52L256R was optimized with the improvement of precursor supply to further increase the production of β-amyrin. Finally, the constructed strains produced 66.97 mg/L β-amyrin in the shake flask, which was 6.45-fold higher than the original strain. Our study provides alternative SQEs for efficient production of β-amyrin as well as other triterpenoids derived from 2,3-oxidosqualene.
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Affiliation(s)
- Jinling Li
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Shuai Wang
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yinan Miao
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Ya Wan
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Chun Li
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China; Key Laboratory for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
| | - Ying Wang
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
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Yan Z, Huang B, Yang K, Anaman R, Amanze C, Jin J, Zhou H, Qiu G, Zeng W. Enlarging the substrate binding pocket of penicillin G acylase from Achromobacter sp. for highly efficient biosynthesis of β-lactam antibiotics. Bioorg Chem 2023; 136:106533. [PMID: 37084587 DOI: 10.1016/j.bioorg.2023.106533] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/23/2023] [Accepted: 04/05/2023] [Indexed: 04/23/2023]
Abstract
Penicillin G acylase (PGA) is a key biocatalyst for the enzymatic production of β-lactam antibiotics, which can not only catalyze the synthesis of β-lactam antibiotics but also catalyze the hydrolysis of the products to prepare semi-synthetic antibiotic intermediates. However, the high hydrolysis and low synthesis activities of natural PGAs severely hinder their industrial application. In this study, a combinatorial directed evolution strategy was employed to obtain new PGAs with outstanding performances. The best mutant βF24G/βW154G was obtained from the PGA of Achromobacter sp., which exhibited approximately a 129.62-fold and a 52.55-fold increase in specific activity and synthesis/hydrolysis ratio, respectively, compared to the wild-type AsPGA. Thereafter, this mutant was used to synthesize amoxicillin, cefadroxil, and ampicillin; all conversions > 99% were accomplished in 90-135 min with almost no secondary hydrolysis byproducts produced in the reaction. Molecular dynamics simulation and substrate pocket calculation revealed that substitution of the smallest glycine residue at βF24 and βW154 expanded the binding pocket, thereby facilitating the entry and release of substrates and products. Therefore, this novel mutant is a promising catalyst for the large-scale production of β-lactam antibiotics.
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Affiliation(s)
- Zhen Yan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Bin Huang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Kai Yang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Richmond Anaman
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Charles Amanze
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Jing Jin
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
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Xu L, Li T, Huo Z, Chen Q, Xia Q, Jiang B. Directed Evolution Improves the Enzymatic Synthesis of L-5-Hydroxytryptophan by an Engineered Tryptophan Synthase. Appl Biochem Biotechnol 2021; 193:3407-3417. [PMID: 34097254 DOI: 10.1007/s12010-021-03589-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/28/2021] [Indexed: 12/01/2022]
Abstract
L-5-Hydroxytryptophan is an important amino acid that is widely used in food and medicine. In this study, L-5-hydroxytryptophan was synthesized by a modified tryptophan synthase. A direct evolution strategy was applied to engineer tryptophan synthase from Escherichia coli to improve the efficiency of L-5-hydroxytryptophan synthesis. Tryptophan synthase was modified by error-prone PCR. A high-activity mutant enzyme (V231A/K382G) was obtained by a high-throughput screening method. The activity of mutant enzyme (V231A/K382G) is 3.79 times higher than that of its parent, and kcat/Km of the mutant enzyme (V231A/K382G) is 4.36 mM-1∙s-1. The mutant enzyme (V231A/K382G) reaction conditions for the production of L-5-hydroxytryptophan were 100 mmol/L L-serine at pH 8.5 and 35°C for 15 h, reaching a yield of L-5-hydroxytryptophan of 86.7%. Directed evolution is an effective strategy to increase the activity of tryptophan synthase.
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Affiliation(s)
- Lisheng Xu
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China.
| | - Tingting Li
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Ziyue Huo
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Qiong Chen
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Qiuxia Xia
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Bianling Jiang
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
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Functional and Phylogenetic Diversity of BSH and PVA Enzymes. Microorganisms 2021; 9:microorganisms9040732. [PMID: 33807488 PMCID: PMC8066178 DOI: 10.3390/microorganisms9040732] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
Bile salt hydrolase (BSH) and penicillin V acylase (PVA) are related enzymes that are classified as choloylglycine hydrolases (CGH). BSH enzymes have attracted significant interest for their ability to modulate the composition of the bile acid pool, alter bile acid signaling events mediated by the host bile acid receptors FXR and TGR5 and influence cholesterol homeostasis in the host, while PVA enzymes have been widely utilised in an industrial capacity in the production of semi-synthetic antibiotics. The similarities between BSH and PVA enzymes suggest common evolution of these enzymes and shared mechanisms for substrate binding and catalysis. Here, we compare BSH and PVA through analysis of the distribution, phylogeny and biochemistry of these microbial enzymes. The development of new annotation approaches based upon functional enzyme analyses and the potential implications of BSH enzymes for host health are discussed.
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Kurahashi R, Tanaka SI, Takano K. Highly active enzymes produced by directed evolution with stability-based selection. Enzyme Microb Technol 2020; 140:109626. [DOI: 10.1016/j.enzmictec.2020.109626] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/12/2020] [Accepted: 06/12/2020] [Indexed: 12/22/2022]
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Hormigo D, López-Conejo MT, Serrano-Aguirre L, García-Martín A, Saborido A, de la Mata I, Arroyo M. Kinetically controlled acylation of 6-APA catalyzed by penicillin acylase from Streptomyces lavendulae: effect of reaction conditions in the enzymatic synthesis of penicillin V. BIOCATAL BIOTRANSFOR 2019. [DOI: 10.1080/10242422.2019.1652274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Daniel Hormigo
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - María Teresa López-Conejo
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - Lara Serrano-Aguirre
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - Alberto García-Martín
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - Ana Saborido
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - Isabel de la Mata
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
| | - Miguel Arroyo
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Enzyme Biotechnology Group, Universidad Complutense de Madrid, Madrid, Spain
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Mayer J, Pippel J, Günther G, Müller C, Lauermann A, Knuuti T, Blankenfeldt W, Jahn D, Biedendieck R. Crystal structures and protein engineering of three different penicillin G acylases from Gram-positive bacteria with different thermostability. Appl Microbiol Biotechnol 2019; 103:7537-7552. [PMID: 31227867 DOI: 10.1007/s00253-019-09977-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/16/2019] [Accepted: 06/10/2019] [Indexed: 10/26/2022]
Abstract
Penicillin G acylase (PGA) catalyzes the hydrolysis of penicillin G to 6-aminopenicillanic acid and phenylacetic acid, which provides the precursor for most semisynthetic penicillins. Most applications rely on PGAs from Gram-negative bacteria. Here we describe the first three crystal structures for PGAs from Gram-positive Bacilli and their utilization in protein engineering experiments for the manipulation of their thermostability. PGAs from Bacillus megaterium (BmPGA, Tm = 56.0 °C), Bacillus thermotolerans (BtPGA, Tm = 64.5 °C), and Bacillus sp. FJAT-27231 (FJAT-PGA, Tm = 74.3 °C) were recombinantly produced with B. megaterium, secreted, purified to apparent heterogeneity, and crystallized. Structures with resolutions of 2.20 Å (BmPGA), 2.27 Å (BtPGA), and 1.36 Å (FJAT-PGA) were obtained. They revealed high overall similarity, reflecting the high identity of up to approx. 75%. Notably, the active center displays a deletion of more than ten residues with respect to PGAs from Gram-negatives. This enlarges the substrate binding site and may indicate a different substrate spectrum. Based on the structures, ten single-chain FJAT-PGAs carrying artificial linkers were produced. However, in all cases, complete linker cleavage was observed. While thermostability remained in the wild-type range, the enzymatic activity dropped between 30 and 60%. Furthermore, four hybrid PGAs carrying subunits from two different enzymes were successfully produced. Their thermostabilities mostly lay between the values of the two mother enzymes. For one PGA increased, enzyme activity was observed. Overall, the three novel PGA structures combined with initial protein engineering experiments provide the basis for establishment of new PGA-based biotechnological processes.
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Affiliation(s)
- Janine Mayer
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Jan Pippel
- HZI - Helmholtz Centre for Infection Research, Structure and Function of Proteins, Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Gabriele Günther
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Carolin Müller
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Anna Lauermann
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Tobias Knuuti
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Wulf Blankenfeldt
- HZI - Helmholtz Centre for Infection Research, Structure and Function of Proteins, Inhoffenstraße 7, 38124, Braunschweig, Germany.,Institute of Biotechnology, Biochemistry and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Dieter Jahn
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Rebekka Biedendieck
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany.
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