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Kuan JE, Tsai CH, Chou CC, Wu C, Wu WF. Enzymatic Characterization of a Novel HSL Family IV Esterase EstD04 from Pseudomonas sp. D01 in Mealworm Gut Microbiota. Molecules 2023; 28:5410. [PMID: 37513282 PMCID: PMC10385968 DOI: 10.3390/molecules28145410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Pseudomonas sp. D01, capable of growing in tributyrin medium, was isolated from the gut microbiota of yellow mealworm. By using in silico analyses, we discovered a hypothesized esterase encoding gene in the D01 bacterium, and its encoded protein, EstD04, was classified as a bacterial hormone-sensitive lipase (bHSL) of the type IV lipase family. The study revealed that the recombinant EstD04-His(6x) protein exhibited esterase activity and broad substrate specificity, as it was capable of hydrolyzing p-nitrophenyl derivatives with different acyl chain lengths. By using the most favorable substrate p-nitrophenyl butyrate (C4), we defined the optimal temperature and pH value for EstD04 esterase activity as 40 °C and pH 8, respectively, with a catalytic efficiency (kcat/Km) of 6.17 × 103 mM-1 s-1 at 40 °C. EstD04 demonstrated high stability between pH 8 and 10, and thus, it might be capably used as an alkaline esterase in industrial applications. The addition of Mg2+ and NH4+, as well as DMSO, could stimulate EstD04 enzyme activity. Based on bioinformatic motif analyses and tertiary structural simulation, we determined EstD04 to be a typical bHSL protein with highly conserved motifs, including a triad catalytic center (Ser160, Glu253, and His283), two cap regions, hinge sites, and an oxyanion hole, which are important for the type IV enzyme activity. Moreover, the sequence analysis suggested that the two unique discrete cap regions of EstD04 may contribute to its alkali mesophilic nature, allowing EstD04 to exhibit extremely distinct physiological properties from its evolutionarily closest esterase.
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Affiliation(s)
- Jung-En Kuan
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Hsuan Tsai
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701401, Taiwan
| | - Chun-Chi Chou
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Cindy Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
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In Vivo Characterization and Application of the PHA Synthase from Azotobacter vinelandii for the Biosynthesis of Polyhydroxyalkanoate Containing 4-Hydroxybutyrate. Polymers (Basel) 2021; 13:polym13101576. [PMID: 34069008 PMCID: PMC8156725 DOI: 10.3390/polym13101576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/10/2021] [Accepted: 05/12/2021] [Indexed: 11/26/2022] Open
Abstract
Polyhydroxyalkanoate (PHA) is a biodegradable thermoplastic naturally synthesized by many microorganisms, and the PHA synthase (PhaC) is known to be the key enzyme involved in determining the material properties and monomer composition of the produced PHA. The ability to exploit widely distributed, commonly found soil microorganisms such as Azotobacter vinelandii to synthesize PHA containing the lipase-degradable 4-hydroxybutyrate (4HB) monomer will allow for convenient production of biocompatible and flexible PHA. Comparisons between the A. vinelandii wild type and mutant strains, with and without a surface layer (S-layer), respectively, in terms of gene or amino acid sequences, synthase activity, granule morphology, and PHA productivity, revealed that the S-layer is the sole factor affecting PHA biosynthesis by A. vinelandii. Based on PHA biosynthesis using different carbon sources, the PhaC of A. vinelandii showed specificity for short-chain-length PHA monomers, making it a member of the Class I PHA synthases. In addition, it was proven that the PhaC of A. vinelandii has the inherent ability to polymerize 4-hydroxybutyrate (4HB) and the mediated accumulation of PHA with 4HB fractions ranging from 10 mol% to as high as 22 mol%. The synthesis of biocompatible PHA containing tailorable amounts of 4HB with an expanded range of elasticity and lipase-degradability will enable a wider range of applications in the biomedical field.
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Huong KH, Sevakumaran V, Amirul AA. P(3HB- co-4HB) as high value polyhydroxyalkanoate: its development over recent decades and current advances. Crit Rev Biotechnol 2021; 41:474-490. [PMID: 33726581 DOI: 10.1080/07388551.2020.1869685] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Polyhydroxyalkanoate (PHA) is a biogenic polymer that has the potential to substitute synthetic plastic in numerous applications. This is due to its unique attribute of being a biodegradable and biocompatible thermoplastic, achievable through microbial fermentation from a broad utilizable range of renewable resources. Among all the PHAs discovered, poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] stands out as a next generation healthcare biomaterial for having high biopharmaceutical and medical value since it is highly compatible to mammalian tissue. This review provides a critical assessment and complete overview of the development and trend of P(3HB-co-4HB) research over the last few decades, highlighting aspects from the microbial strain discovery to metabolic engineering and bioprocess cultivation strategies. The article also outlines the relevance of P(3HB-co-4HB) as a material for high value-added products in numerous healthcare-related applications.
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Affiliation(s)
- Kai-Hee Huong
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Vigneswari Sevakumaran
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Nerus, Kuala Terengganu, Terengganu, Malaysia
| | - A A Amirul
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia.,Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Penang, Malaysia.,Malaysian Institute of Pharmaceuticals and Nutraceuticals, NIBM, Gelugor, Penang, Malaysia
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Cal AJ, Kibblewhite RE, Sikkema WD, Torres LF, Hart-Cooper WM, Orts WJ, Lee CC. Production of polyhydroxyalkanoate copolymers containing 4-hydroxybutyrate in engineered Bacillus megaterium. Int J Biol Macromol 2020; 168:86-92. [PMID: 33290766 DOI: 10.1016/j.ijbiomac.2020.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/18/2020] [Accepted: 12/03/2020] [Indexed: 11/15/2022]
Abstract
Despite being used as a common platform for the commercial production of many biochemicals, Bacilli are often overlooked as a source of industrial polyhydroxyalkanoates (PHAs), biodegradable plastic replacements. In addition to having a robust expression system, the lack of lipopolysaccharides and ease of lysis make Bacilli an attractive host for the production of PHAs. In this work, a Bacillus megaterium strain was engineered to generate poly(3-hydroxybutyrate-co-4-hydroxybutryate) (P[3HB-co-4HB]) copolymers, which are among the most useful and industrially-relevant copolymers. These copolymers had lower modulus and increased toughness, thus making the copolymer suitable for a broader range of applications. Due to high metabolic flux through succinate, the engineered B. megaterium strain produced P(3HB-co-4HB) with >10% mol fraction 4HB from glucose, without the use of highly regulated and expensive precursors or potentially damaging truncation of central biochemical pathways.
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Affiliation(s)
- Andrew J Cal
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Rena E Kibblewhite
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - W Dirk Sikkema
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Lennard F Torres
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - William M Hart-Cooper
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - William J Orts
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Charles C Lee
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA.
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Tanweer S, Panda B. Prospect of Synechocystis sp. PCC 6803 for synthesis of poly(3-hydroxybutyrate-co-4-hydroxybutyrate). ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Taxon ES, Halbers LP, Parsons SM. Kinetics aspects of Gamma-hydroxybutyrate dehydrogenase. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2020; 1868:140376. [PMID: 31981617 DOI: 10.1016/j.bbapap.2020.140376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 12/22/2019] [Accepted: 01/19/2020] [Indexed: 11/18/2022]
Abstract
Two groups of metabolically related enzymes, the Group III family of Fe2+-dependent alcohol dehydrogenases (ADHs) and the separate subfamily of nucleoside diphosphates linked to x (nudix) hydrolases that activate Group III ADHs are under-characterized. Here we report the steady-state initial-velocity forward direction (alcohol → aldehyde) reaction of a Group III ADH, namely gamma-hydroxybutyrate dehydrogenase (GHBDH, UniProt: Q59104), cloned from Cupriavidus necator as a fusion protein. We also report the effects of nudix hydrolases on the GHBDH reaction. At optimal pH 9.0, the GHBDH reaction is activated ~2-fold by two different saturating purified nudix hydrolases, namely Bacillus methanolicus activator (ACT, UniProt: I3EA59) and Escherichia coli NudF (UniProt Q93K97) proteins. At physiological pH values of ~7.0, ACT activates by >3.5-fold. Initial-rate characterization at pH 9.0 of the forward direction un-activated and ACT-activated reactions show for both cases competitive inhibition by the product succinic semialdehyde versus GHB, and noncompetitive inhibitions by the three other substrate-product combinations. This pattern is consistent with NAD+ binding first in Mono-Iso Theorell-Chance kinetics. Mutants of some possibly important residues in GHBDH also were characterized. H265, conserved among all Group III ADHs and previously proposed to be a critical general base, is only ~4-fold helpful for GHBDH activity relevant to H265A. The four previously proposed conserved Fe2+ chelators (D193, H197, H261 and H280) each are essential for GHBDH activity. A 2-step explanation for cross-species stimulation by sub-stoichiometric ACT in the forward direction and confirmed lack of ACT stimulation in the reverse direction reaction is proposed.
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Affiliation(s)
- Esther S Taxon
- Department of Chemistry and Biochemistry, Department of Biomolecular Science and Engineering, University of California, Santa Barbara, California, United States
| | - Lila P Halbers
- Department of Chemistry and Biochemistry, Department of Biomolecular Science and Engineering, University of California, Santa Barbara, California, United States
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, Department of Biomolecular Science and Engineering, University of California, Santa Barbara, California, United States.
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Utsunomia C, Ren Q, Zinn M. Poly(4-Hydroxybutyrate): Current State and Perspectives. Front Bioeng Biotechnol 2020; 8:257. [PMID: 32318554 PMCID: PMC7147479 DOI: 10.3389/fbioe.2020.00257] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/12/2020] [Indexed: 12/15/2022] Open
Abstract
By the end of 1980s, for the first time polyhydroxyalkanoate (PHA) copolymers with incorporated 4-hydroxybutyrate (4HB) units were produced in the bacterium Cupriavidus necator (formally Ralstonia eutropha) from structurally related carbon sources. After that, production of PHA copolymers composed of 3-hydroxybutyrate (3HB) and 4HB [P(3HB-co-4HB)] was demonstrated in diverse wild-type bacteria. The P4HB homopolymer, however, was hardly synthesized because existing bacterial metabolism on 4HB precursors also generate and incorporate 3HB. The resulting material assumes the properties of thermoplastics and elastomers depending on the 4HB fraction in the copolyester. Given the fact that P4HB is biodegradable and yield 4HB, which is a normal compound in the human body and proven to be biocompatible, P4HB has become a prospective material for medical applications, which is the only FDA approved PHA for medical applications since 2007. Different from other materials used in similar applications, high molecular weight P4HB cannot be produced via chemical synthesis. Thus, aiming at the commercial production of this type of PHA, genetic engineering was extensively applied resulting in various production strains, with the ability to convert unrelated carbon sources (e.g., sugars) to 4HB, and capable of producing homopolymeric P4HB. In 2001, Metabolix Inc. filed a patent concerning genetically modified and stable organisms, e.g., Escherichia coli, producing P4HB and copolymers from inexpensive carbon sources. The patent is currently hold by Tepha Inc., the only worldwide producer of commercial P4HB. To date, numerous patents on various applications of P4HB in the medical field have been filed. This review will comprehensively cover the historical evolution and the most recent publications on P4HB biosynthesis, material properties, and industrial and medical applications. Finally, perspectives for the research and commercialization of P4HB will be presented.
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Affiliation(s)
- Camila Utsunomia
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), Sion, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Manfred Zinn
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), Sion, Switzerland
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Johnson AO, Gonzalez-Villanueva M, Tee KL, Wong TS. An Engineered Constitutive Promoter Set with Broad Activity Range for Cupriavidus necator H16. ACS Synth Biol 2018; 7:1918-1928. [PMID: 29949349 DOI: 10.1021/acssynbio.8b00136] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Well-characterized promoters with variable strength form the foundation of heterologous pathway optimization. It is also a key element that bolsters the success of microbial engineering and facilitates the development of biological tools like biosensors. In comparison to microbial hosts such as Escherichia coli and Saccharomyces cerevisiae, the promoter repertoire of Cupriavidus necator H16 is highly limited. This limited number of characterized promoters poses a significant challenge during the engineering of C. necator H16 for biomanufacturing and biotechnological applications. In this article, we first examined the architecture and genetic elements of the four most widely used constitutive promoters of C. necator H16 (i.e., P phaC1, P rrsC, P j5, and P g25) and established a narrow 6-fold difference in their promoter activities. Next, using these four promoters as starting points and applying a range of genetic modifications (including point mutation, length alteration, incorporation of regulatory genetic element, promoter hybridization, and configuration alteration), we created a library of 42 constitutive promoters, all of which are functional in C. necator H16. Although these promoters are also functional in E. coli, they show different promoter strength and hierarchical rank of promoter activity. Subsequently, the activity of each promoter was individually characterized, using l-arabinose-inducible P BAD promoter as a benchmark. This study has extended the range of constitutive promoter activities to 137-fold, with some promoter variants exceeding the l-arabinose-inducible range of P BAD promoter. Not only has the work enhanced our flexibility in engineering C. necator H16, it presented novel strategies in adjusting promoter activity in C. necator H16 and highlighted similarities and differences in transcriptional activity between this organism and E. coli.
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Affiliation(s)
- Abayomi Oluwanbe Johnson
- Department of Chemical & Biological Engineering and Advanced Biomanufacturing Centre, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - Miriam Gonzalez-Villanueva
- Department of Chemical & Biological Engineering and Advanced Biomanufacturing Centre, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - Kang Lan Tee
- Department of Chemical & Biological Engineering and Advanced Biomanufacturing Centre, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - Tuck Seng Wong
- Department of Chemical & Biological Engineering and Advanced Biomanufacturing Centre, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, United Kingdom
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Fed-Batch Synthesis of Poly(3-Hydroxybutyrate) and Poly(3-Hydroxybutyrate-co-4-Hydroxybutyrate) from Sucrose and 4-Hydroxybutyrate Precursors by Burkholderia sacchari Strain DSM 17165. Bioengineering (Basel) 2017; 4:bioengineering4020036. [PMID: 28952515 PMCID: PMC5590455 DOI: 10.3390/bioengineering4020036] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 04/13/2017] [Accepted: 04/19/2017] [Indexed: 11/22/2022] Open
Abstract
Based on direct sucrose conversion, the bacterium Burkholderia sacchari is an excellent producer of the microbial homopolyester poly(3-hydroxybutyrate) (PHB). Restrictions of the strain’s wild type in metabolizing structurally related 3-hydroxyvalerate (3HV) precursors towards 3HV-containing polyhydroxyalkanoate (PHA) copolyester calls for alternatives. We demonstrate the highly productive biosynthesis of PHA copolyesters consisting of 3-hydroxybuytrate (3HB) and 4-hydroxybutyrate (4HB) monomers. Controlled bioreactor cultivations were carried out using saccharose from the Brazilian sugarcane industry as the main carbon source, with and without co-feeding with the 4HB-related precursor γ-butyrolactone (GBL). Without GBL co-feeding, the homopolyester PHB was produced at a volumetric productivity of 1.29 g/(L·h), a mass fraction of 0.52 g PHB per g biomass, and a final PHB concentration of 36.5 g/L; the maximum specific growth rate µmax amounted to 0.15 1/h. Adding GBL, we obtained 3HB and 4HB monomers in the polyester at a volumetric productivity of 1.87 g/(L·h), a mass fraction of 0.72 g PHA per g biomass, a final PHA concentration of 53.7 g/L, and a µmax of 0.18 1/h. Thermoanalysis revealed improved material properties of the second polyester in terms of reduced melting temperature Tm (161 °C vs. 178 °C) and decreased degree of crystallinity Xc (24% vs. 71%), indicating its enhanced suitability for polymer processing.
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Volodina E, Raberg M, Steinbüchel A. Engineering the heterotrophic carbon sources utilization range of Ralstonia eutropha H16 for applications in biotechnology. Crit Rev Biotechnol 2015; 36:978-991. [PMID: 26329669 DOI: 10.3109/07388551.2015.1079698] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ralstonia eutropha H16 is an interesting candidate for the biotechnological production of polyesters consisting of hydroxy- and mercaptoalkanoates, and other compounds. It provides all the necessary characteristics, which are required for a biotechnological production strain. Due to its metabolic versatility, it can convert a broad range of renewable heterotrophic resources into diverse valuable compounds. High cell density fermentations of the non-pathogenic R. eutropha can be easily performed. Furthermore, this bacterium is accessible to engineering of its metabolism by genetic approaches having available a large repertoire of genetic tools. Since the complete genome sequence of R. eutropha H16 has become available, a variety of transcriptome, proteome and metabolome studies provided valuable data elucidating its complex metabolism and allowing a systematic biology approach. However, high production costs for bacterial large-scale production of biomass and biotechnologically valuable products are still an economic challenge. The application of inexpensive raw materials could significantly reduce the expenses. Therefore, the conversion of diverse substrates to polyhydroxyalkanoates by R. eutropha was steadily improved by optimization of cultivation conditions, mutagenesis and metabolic engineering. Industrial by-products and residual compounds like glycerol, and substrates containing high carbon content per weight like palm, soybean, corn oils as well as raw sugar-rich materials like molasses, starch and lignocellulose, are the most promising renewable substrates and were intensively studied.
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Affiliation(s)
- Elena Volodina
- a Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster , Germany and
| | - Matthias Raberg
- a Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster , Germany and
| | - Alexander Steinbüchel
- a Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster , Germany and.,b Environmental Science Department, King Abdulaziz University , Jeddah , Saudi Arabia
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Lv L, Ren YL, Chen JC, Wu Q, Chen GQ. Application of CRISPRi for prokaryotic metabolic engineering involving multiple genes, a case study: Controllable P(3HB-co-4HB) biosynthesis. Metab Eng 2015; 29:160-168. [PMID: 25838211 DOI: 10.1016/j.ymben.2015.03.013] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 03/21/2015] [Accepted: 03/23/2015] [Indexed: 01/08/2023]
Abstract
Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is used to edit eukaryotic genomes. Here, we show that CRISPRi can also be used for fine-tuning prokaryotic gene expression while simultaneously regulating multiple essential gene expression with less labor and time consumption. As a case study, CRISPRi was used to control polyhydroxyalkanoate (PHA) biosynthesis pathway flux and to adjust PHA composition. A pathway was constructed in Escherichia coli for the production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] from glucose. The native gene sad encoding E. coli succinate semi-aldehyde dehydrogenase was expressed under the control of CRISPRi using five specially designed single guide RNAs (sgRNAs) for regulating carbon flux to 4-hydroxybutyrate (4HB) biosynthesis. The system allowed formation of P(3HB-co-4HB) consisting of 1-9mol% 4HB. Additionally, succinate, generated by succinyl-coA synthetase and succinate dehydrogenase (respectively encoded by genes sucC, sucD and sdhA, sdhB) was channeled preferentially to the 4HB precursor by using selected sgRNAs such as sucC2, sucD2, sdhB2 and sdhA1 via CRISPRi. The resulting 4HB content in P(3HB-co-4HB) was found to range from 1.4 to 18.4mol% depending on the expression levels of down-regulated genes. The results show that CRISPRi is a feasible method to simultaneously manipulate multiple genes in E. coli.
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Affiliation(s)
- Li Lv
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yi-Lin Ren
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jin-Chun Chen
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiong Wu
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guo-Qiang Chen
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China; Center for Nano and Micro-Mechanics, Tsinghua University, Beijing 100084, China.
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Production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by Burkholderia sacchari using wheat straw hydrolysates and gamma-butyrolactone. Int J Biol Macromol 2014; 71:59-67. [DOI: 10.1016/j.ijbiomac.2014.04.054] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/11/2014] [Accepted: 04/25/2014] [Indexed: 11/23/2022]
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13
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Le Meur S, Zinn M, Egli T, Thöny-Meyer L, Ren Q. Improved productivity of poly (4-hydroxybutyrate) (P4HB) in recombinant Escherichia coli using glycerol as the growth substrate with fed-batch culture. Microb Cell Fact 2014; 13:131. [PMID: 25176327 PMCID: PMC4160554 DOI: 10.1186/s12934-014-0131-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/26/2014] [Indexed: 11/14/2022] Open
Abstract
Background The most successful polyhydroxyalkanoate (PHA) in medical applications is poly(4-hydroxybutyrate) (P4HB), which is due to its biodegradability, biocompatibility and mechanical properties. One of the major obstacles for wider applications of P4HB is the cost of production and purification. It is highly desired to obtain P4HB in large scale at a competitive cost. Results In this work, we studied the possibility to increase P4HB productivity by using high cell density culture. To do so, we investigated for the first time some of the most relevant factors influencing P4HB biosynthesis in recombinant Escherichia coli. We observed that P4HB biosynthesis correlated more with limitations of amino acids and less with nitrogen depletion, contrary to the synthesis of many other types of PHAs. Furthermore, it was found that using glycerol as the primary carbon source, addition of acetic acid at the beginning of a batch culture stimulated P4HB accumulation in E. coli. Fed-batch high cell density cultures were performed to reach high P4HB productivity using glycerol as the sole carbon source for cell growth and 4HB as the precursor for P4HB synthesis. A P4HB yield of 15 g L−1 was obtained using an exponential feeding mode, leading to a productivity of 0.207 g L−1 h−1, which is the highest productivity for P4HB reported so far. Conclusions We demonstrated that the NZ-amines (amino acids source) in excess abolished P4HB accumulation, suggesting that limitation in certain amino acid pools promotes P4HB synthesis. Furthermore, the enhanced P4HB yield could be achieved by both the effective growth of E. coli JM109 (pKSSE5.3) on glycerol and the stimulated P4HB synthesis via exogenous addition of acetic acid. We have developed fermentation strategies for P4HB production by using glycerol, leading to a productivity of 0.207 g L−1 h−1 P4HB. This high P4HB productivity will decrease the total production cost, allowing further development of P4HB applications.
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Structural characterization of a β-hydroxyacid dehydrogenase from Geobacter sulfurreducens and Geobacter metallireducens with succinic semialdehyde reductase activity. Biochimie 2014; 104:61-9. [PMID: 24878278 DOI: 10.1016/j.biochi.2014.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/09/2014] [Indexed: 11/23/2022]
Abstract
Beta-hydroxyacid dehydrogenase (β-HAD) genes have been identified in all sequenced genomes of eukaryotes and prokaryotes. Their gene products catalyze the NAD(+)- or NADP(+)-dependent oxidation of various β-hydroxy acid substrates into their corresponding semialdehyde. In many fungal and bacterial genomes, multiple β-HAD genes are observed leading to the hypothesis that these gene products may have unique, uncharacterized metabolic roles specific to their species. The genomes of Geobacter sulfurreducens and Geobacter metallireducens each contain two potential β-HAD genes. The protein sequences of one pair of these genes, Gs-βHAD (Q74DE4) and Gm-βHAD (Q39R98), have 65% sequence identity and 77% sequence similarity with each other. Both proteins are observed to reduce succinic semialdehyde, a 4-carbon substrate instead of the typical β-HAD 3-carbon substrate, to γ-hydroxybutyric acid. To further explore the structural and functional characteristics of these two β-HADs with a less frequently observed substrate specificity, crystal structures for Gs-βHAD and Gm-βHAD in complex with NADP(+) were determined to a resolution of 1.89 Å and 2.07 Å, respectively. The structures of both proteins are similar, composed of 14 α-helices and nine β-strands organized into two domains. Domain 1 (1-165) adopts a typical Rossmann fold composed of two α/β units: a six-strand parallel β-sheet surrounded by six α-helices (α1-α6) followed by a mixed three-strand β-sheet surrounded by two α-helices (α7 and α8). Domain 2 (166-287) is composed of a bundle of seven α-helices (α9-α14). Four functional regions conserved in all β-HADs are spatially located near each other, with a buried molecule of NADP(+), at the interdomain cleft. Comparison of these Geobacter structures to a closely related β-HAD from Arabidopsis thaliana in the apo-NADP(+) and apo-substrate bound state suggests that NADP(+) binding effects a rigid body rotation between Domains 1 and 2. Bound near the Substrate-Binding and Catalysis Regions in two of the eight protomers in the asymmetric unit of Gm-βHAD is a glycerol molecule that may mimic features of bound biological substrates.
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Hawkins AS, Han Y, Bennett RK, Adams MWW, Kelly RM. Role of 4-hydroxybutyrate-CoA synthetase in the CO2 fixation cycle in thermoacidophilic archaea. J Biol Chem 2012; 288:4012-22. [PMID: 23258541 DOI: 10.1074/jbc.m112.413195] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Metallosphaera sedula is an extremely thermoacidophilic archaeon that grows heterotrophically on peptides and chemolithoautotrophically on hydrogen, sulfur, or reduced metals as energy sources. During autotrophic growth, carbon dioxide is incorporated into cellular carbon via the 3-hydroxypropionate/4-hydroxybutyrate cycle (3HP/4HB). To date, all of the steps in the pathway have been connected to enzymes encoded in specific genes, except for the one responsible for ligation of coenzyme A (CoA) to 4HB. Although several candidates for this step have been identified through bioinformatic analysis of the M. sedula genome, none have been shown to catalyze this biotransformation. In this report, transcriptomic analysis of cells grown under strict H(2)-CO(2) autotrophy was consistent with the involvement of Msed_0406 and Msed_0394. Recombinant versions of these enzymes catalyzed the ligation of CoA to 4HB, with similar affinities for 4HB (K(m) values of 1.9 and 1.5 mm for Msed_0406 and Msed_0394, respectively) but with different rates (1.69 and 0.22 μmol × min(-1) × mg(-1) for Msed_0406 and Msed_0394, respectively). Neither Msed_0406 nor Msed_0394 have close homologs in other Sulfolobales, although low sequence similarity is not unusual for acyl-adenylate-forming enzymes. The capacity of these two enzymes to use 4HB as a substrate may have arisen from simple modifications to acyl-adenylate-forming enzymes. For example, a single amino acid substitution (W424G) in the active site of the acetate/propionate synthetase (Msed_1353), an enzyme that is highly conserved among the Sulfolobales, changed its substrate specificity to include 4HB. The identification of the 4-HB CoA synthetase now completes the set of enzymes comprising the 3HP/4HB cycle.
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Affiliation(s)
- Aaron S Hawkins
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, USA
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Zhou XY, Yuan XX, Shi ZY, Meng DC, Jiang WJ, Wu LP, Chen JC, Chen GQ. Hyperproduction of poly(4-hydroxybutyrate) from glucose by recombinant Escherichia coli. Microb Cell Fact 2012; 11:54. [PMID: 22550959 PMCID: PMC3527305 DOI: 10.1186/1475-2859-11-54] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Accepted: 04/26/2012] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Poly(4-hydroxybutyrate) [poly(4HB)] is a strong thermoplastic biomaterial with remarkable mechanical properties, biocompatibility and biodegradability. However, it is generally synthesized when 4-hydroxybutyrate (4HB) structurally related substrates such as γ-butyrolactone, 4-hydroxybutyrate or 1,4-butanediol (1,4-BD) are provided as precursor which are much more expensive than glucose. At present, high production cost is a big obstacle for large scale production of poly(4HB).
Results
Recombinant Escherichia coli strain was constructed to achieve hyperproduction of poly(4-hydroxybutyrate) [poly(4HB)] using glucose as a sole carbon source. An engineering pathway was established in E. coli containing genes encoding succinate degradation of Clostridium kluyveri and PHB synthase of Ralstonia eutropha. Native succinate semialdehyde dehydrogenase genes sad and gabD in E. coli were both inactivated to enhance the carbon flux to poly(4HB) biosynthesis. Four PHA binding proteins (PhaP or phasins) including PhaP1, PhaP2, PhaP3 and PhaP4 from R. eutropha were heterologously expressed in the recombinant E. coli, respectively, leading to different levels of improvement in poly(4HB) production. Among them PhaP1 exhibited the highest capability for enhanced polymer synthesis. The recombinant E. coli produced 5.5 g L-1 cell dry weight containing 35.4% poly(4HB) using glucose as a sole carbon source in a 48 h shake flask growth. In a 6-L fermentor study, 11.5 g L-1 cell dry weight containing 68.2% poly(4HB) was obtained after 52 h of cultivation. This was the highest poly(4HB) yield using glucose as a sole carbon source reported so far. Poly(4HB) was structurally confirmed by gas chromatographic (GC) as well as 1H and 13C NMR studies.
Conclusions
Significant level of poly(4HB) biosynthesis from glucose can be achieved in sad and gabD genes deficient strain of E. coli JM109 harboring an engineering pathway encoding succinate degradation genes and PHB synthase gene, together with expression of four PHA binding proteins PhaP or phasins, respectively. Over 68% poly(4HB) was produced in a fed-batch fermentation process, demonstrating the feasibility for enhanced poly(4HB) production using the recombinant strain for future cost effective commercial development.
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Yim H, Haselbeck R, Niu W, Pujol-Baxley C, Burgard A, Boldt J, Khandurina J, Trawick JD, Osterhout RE, Stephen R, Estadilla J, Teisan S, Schreyer HB, Andrae S, Yang TH, Lee SY, Burk MJ, Van Dien S. Metabolic engineering of Escherichia coli for direct production of 1,4-butanediol. Nat Chem Biol 2011; 7:445-52. [PMID: 21602812 DOI: 10.1038/nchembio.580] [Citation(s) in RCA: 710] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 04/01/2011] [Indexed: 12/25/2022]
Abstract
1,4-Butanediol (BDO) is an important commodity chemical used to manufacture over 2.5 million tons annually of valuable polymers, and it is currently produced exclusively through feedstocks derived from oil and natural gas. Herein we report what are to our knowledge the first direct biocatalytic routes to BDO from renewable carbohydrate feedstocks, leading to a strain of Escherichia coli capable of producing 18 g l(-1) of this highly reduced, non-natural chemical. A pathway-identification algorithm elucidated multiple pathways for the biosynthesis of BDO from common metabolic intermediates. Guided by a genome-scale metabolic model, we engineered the E. coli host to enhance anaerobic operation of the oxidative tricarboxylic acid cycle, thereby generating reducing power to drive the BDO pathway. The organism produced BDO from glucose, xylose, sucrose and biomass-derived mixed sugar streams. This work demonstrates a systems-based metabolic engineering approach to strain design and development that can enable new bioprocesses for commodity chemicals that are not naturally produced by living cells.
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Affiliation(s)
- Harry Yim
- Genomatica, Inc., San Diego, California, USA
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18
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Vinckier NK, Chworos A, Parsons SM. Improved isolation of proteins tagged with glutathione S-transferase. Protein Expr Purif 2011; 75:161-4. [DOI: 10.1016/j.pep.2010.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 09/03/2010] [Accepted: 09/08/2010] [Indexed: 11/26/2022]
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21
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Saito N, Robert M, Kochi H, Matsuo G, Kakazu Y, Soga T, Tomita M. Metabolite profiling reveals YihU as a novel hydroxybutyrate dehydrogenase for alternative succinic semialdehyde metabolism in Escherichia coli. J Biol Chem 2009; 284:16442-16451. [PMID: 19372223 DOI: 10.1074/jbc.m109.002089] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The search for novel enzymes and enzymatic activities is important to map out all metabolic activities and reveal cellular metabolic processes in a more exhaustive manner. Here we present biochemical and physiological evidence for the function of the uncharacterized protein YihU in Escherichia coli using metabolite profiling by capillary electrophoresis time-of-flight mass spectrometry. To detect enzymatic activity and simultaneously identify possible substrates and products of the putative enzyme, we profiled a complex mixture of metabolites in the presence or absence of YihU. In this manner, succinic semialdehyde was identified as a substrate for YihU. The purified YihU protein catalyzed in vitro the NADH-dependent reduction of succinic semialdehyde to gamma-hydroxybutyrate. Moreover, a yihU deletion mutant displayed reduced tolerance to the cytotoxic effects of exogenous addition of succinic semialdehyde. Profiling of intracellular metabolites following treatment of E. coli with succinic semialdehyde supports the existence of a YihU-catalyzed reduction of succinic semialdehyde to gamma-hydroxybutyrate in addition to its known oxidation to succinate and through the tricarboxylic acid cycle. These findings suggest that YihU is a novel gamma-hydroxybutyrate dehydrogenase involved in the metabolism of succinic semialdehyde, and other potentially toxic intermediates that may accumulate under stress conditions in E. coli.
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Affiliation(s)
- Natsumi Saito
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017.
| | - Martin Robert
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017
| | - Hayataro Kochi
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017
| | - Goh Matsuo
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017
| | - Yuji Kakazu
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017
| | - Tomoyoshi Soga
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017; Human Metabolome Technologies Inc., Tsuruoka, Yamagata 997-0052, Japan
| | - Masaru Tomita
- From the Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017; Human Metabolome Technologies Inc., Tsuruoka, Yamagata 997-0052, Japan
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Diniz SC, Voss I, Steinbüchel A. Optimization of cyanophycin production in recombinant strains of Pseudomonas putida and Ralstonia eutropha employing elementary mode analysis and statistical experimental design. Biotechnol Bioeng 2006; 93:698-717. [PMID: 16435401 DOI: 10.1002/bit.20760] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Elementary mode analysis was applied to simulate conditions for cyanophycin (CGP) biosynthesis and to optimize its production in bacteria. The conclusions from these simulations were confirmed by experiments with recombinant strains of the wild types and polyhydroxyalkanoate (PHA)-negative mutants of Ralstonia eutropha and Pseudomonas putida expressing CGP synthetase genes (cphA) of Synechocystis sp. strain PCC6308 or Anabaena sp. strain PCC7120. In particular, the effects of suitable precursor substrates and of oxygen supply as well as of the capability to accumulate PHA in addition to CGP biosynthesis were investigated. Since CGP consists of the amino acids aspartate and arginine, the tricarboxylic acid cycle (TCC), which provides intermediates for biosynthesis of these amino acids, seems to be important. Excretion of intermediates of the TCC upon cultivation at restricted oxygen supply and conversion of fumarate mainly to malate and to only little succinate in the absence of oxygen indicated that TCC intermediates for arginine and aspartate biosynthesis were provided by the oxidative or reductive parts of the TCC, respectively. The following important conclusions were made from the experiments and the simulations: (i) external arginine additionally supplied to the medium, (ii) oxygen limitation, and (iii) absence of PHA accumulation exerted positive effects on CGP accumulation. These conclusions were utilized to obtain CGP contents in the cells of as high as 17.9% (w x w(-1)) during cultivation of the investigated bacteria at the 30-L scale using mineral salts medium. Such high CGP contents were previously not obtained with these bacteria at a 30-L scale, even if complex media were used.
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Affiliation(s)
- Simone Cardoso Diniz
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, D-48149 Münster, Germany
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Kashima Y, Nakajima Y, Nakano T, Tayama K, Koizumi Y, Udaka S, Yanagida F. Cloning and characterization of ethanol-regulated esterase genes in Acetobacter pasteurianus. J Biosci Bioeng 2005; 87:19-27. [PMID: 16232420 DOI: 10.1016/s1389-1723(99)80003-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/1998] [Accepted: 09/30/1998] [Indexed: 11/25/2022]
Abstract
The esterase encoding genes, est1 and est2, were cloned from Acetobacter pasteurianus. Nucleotide sequence analysis of est1 revealed a gene of 954 bp, and est1 coded for an arylesterase with a molecular weight of 34863 Da consisting of 317 amino acids. The est2 gene contained an open reading frame composed of 1221 bp encoding an esterase with a molecular weight of 43389 Da consisting of 406 amino acids. The est1 gene showed some similarity, but the est2 gene showed no significant homology to other esterases reported in various microorganisms. Northern blot analysis of total RNA from A. pasteurianus revealed that transcription of the est1 gene was induced only when the cells were grown in a medium containing ethanol, and suggested that the est1 transcript is monocistronic. In contrast, transcription of the est2 gene was repressed in the presence of ethanol. In the absence of ethanol, expression of the est2-mRNA, capable of encoding a multiple number of proteins, was revealed by Northern blot analysis. In addition, deletion analysis indicated that the 5'-region of the est2 gene contained a cis-acting domain for est2 transcriptional regulation. Analysis of the est1 promoter using the chloramphenicol acetyltransferase gene as a reporter gene showed that the promoter within the 305-bp fragment upstream of the ATG initiation codon was responsible for the transcription in cells grown in the presence of ethanol. Primer extension analysis of est1-mRNA showed that the transcription initiation site was 49 bp upstream from the ATG initiation codon. The results of a gel mobility shift assay indicated that there is a regulatory protein related to est1 regulation, which may have some relation to the ethanol resistance of Acetobacter sp.
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Affiliation(s)
- Y Kashima
- Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502 Japan
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Ko MK, Jeon WB, Kim KS, Lee HH, Seo HH, Kim YS, Oh BJ. A Colletotrichum gloeosporioides-induced esterase gene of nonclimacteric pepper (Capsicum annuum) fruit during ripening plays a role in resistance against fungal infection. PLANT MOLECULAR BIOLOGY 2005; 58:529-41. [PMID: 16021337 DOI: 10.1007/s11103-005-7088-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Accepted: 05/09/2005] [Indexed: 05/03/2023]
Abstract
Ripe fruits of pepper (Capsicum annuum) are resistant to the anthracnose fungus, Colletotrichum gloeosporioides, whereas unripe-mature fruits are susceptible. A pepper esterase gene (PepEST) that is highly expressed during an incompatible interaction between the ripe fruit of pepper and C. gloeosporioides was previously cloned. Deduced amino acid sequence of PepEST cDNA showed homology to both esterases and lipases, and contained -HGGGF- and -GXSXG- motifs and a catalytic triad. Inhibition of PepEST activity by a specific inhibitor of serine hydrolase demonstrated that a serine residue is critical for the enzyme activity. Expression of PepEST gene was fruit-specific in response to C. gloeosporioides inoculation, and up-regulated by wounding or jasmonic acid treatment during ripening. PepEST mRNA and protein was differentially accumulated in ripe vs. unripe fruit from 24 h after inoculation when C. gloeosporioides is invading into fruits. Immunochemical examination revealed that PepEST accumulation was localized in epidermal and cortical cell layers in infected ripe fruit, but rarely even in epidermal cells in infected unripe one. Over-expression of PepEST in transgenic Arabidopsis plants caused restriction of Alternaria brassicicola colonization by inhibition of spore production, resulting in enhanced resistance against A.brassicicola. These results suggest that PepEST is involved in the resistance of ripe fruit against C.gloeosporioides infection.
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MESH Headings
- Abscisic Acid/pharmacology
- Acetates/pharmacology
- Alternaria/growth & development
- Amino Acid Sequence
- Arabidopsis/genetics
- Arabidopsis/microbiology
- Capsicum/enzymology
- Capsicum/genetics
- Capsicum/growth & development
- Colletotrichum/growth & development
- Cyclopentanes/pharmacology
- Electrophoresis, Polyacrylamide Gel
- Esterases/genetics
- Esterases/metabolism
- Fruit/enzymology
- Fruit/genetics
- Fruit/growth & development
- Gene Expression Regulation, Developmental/drug effects
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Plant/drug effects
- Immunity, Innate/genetics
- Molecular Sequence Data
- Organophosphorus Compounds/pharmacology
- Oxylipins
- Plant Diseases/genetics
- Plant Diseases/microbiology
- Plant Growth Regulators/pharmacology
- Plants, Genetically Modified
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Proteins/metabolism
- Salicylic Acid/pharmacology
- Sequence Alignment
- Sequence Homology, Amino Acid
- Stress, Mechanical
- Time Factors
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Affiliation(s)
- Moon Kyung Ko
- Kumho Life and Environmental Science Laboratory, Korea Kumho Petrochemical Co., Ltd., Buk-gu, Gwangju, Korea
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Steinbüchel A, Lütke-Eversloh T. Metabolic engineering and pathway construction for biotechnological production of relevant polyhydroxyalkanoates in microorganisms. Biochem Eng J 2003. [DOI: 10.1016/s1369-703x(03)00036-6] [Citation(s) in RCA: 326] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Breitkreuz KE, Allan WL, Van Cauwenberghe OR, Jakobs C, Talibi D, Andre B, Shelp BJ. A novel gamma-hydroxybutyrate dehydrogenase: identification and expression of an Arabidopsis cDNA and potential role under oxygen deficiency. J Biol Chem 2003; 278:41552-6. [PMID: 12882961 DOI: 10.1074/jbc.m305717200] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In plants, gamma-aminobutyrate (GABA), a non-protein amino acid, accumulates rapidly in response to a variety of abiotic stresses such as oxygen deficiency. Under normoxia, GABA is catabolized to succinic semialdehyde and then to succinate with the latter reaction being catalyzed by succinic semialdehyde dehydrogenase (SSADH). Complementation of an SSADH-deficient yeast mutant with an Arabidopsis cDNA library enabled the identification of a novel cDNA (designated as AtGH-BDH for Arabidopsis thaliana gamma-hydroxybutyrate dehydrogenase), which encodes a 289-amino acid polypeptide containing an NADP-binding domain. Constitutive expression of AtGHBDH in the mutant yeast enabled growth on 20 mm GABA and significantly enhanced the cellular concentrations of gamma-hydroxybutyrate, the product of the GHDBH reaction. These data confirm that the cDNA encodes a polypeptide with GHBDH activity. Arabidopsis plants subjected to flooding-induced oxygen deficiency for up to 4 h possessed elevated concentrations of gamma-hydroxybutyrate as well as GABA and alanine. RNA expression analysis revealed that GHBDH transcription was not up-regulated by oxygen deficiency. These findings suggest that GHBDH activity is regulated by the supply of succinic semialdehyde or by redox balance. It is proposed that GHBDH and SSADH activities in plants are regulated in a complementary fashion and that GHBDH and gamma-hydroxybutyrate function in oxidative stress tolerance.
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Affiliation(s)
- Kevin E Breitkreuz
- Department of Plant Agriculture, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Hektor HJ, Kloosterman H, Dijkhuizen L. Identification of a magnesium-dependent NAD(P)(H)-binding domain in the nicotinoprotein methanol dehydrogenase from Bacillus methanolicus. J Biol Chem 2002; 277:46966-73. [PMID: 12351635 DOI: 10.1074/jbc.m207547200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Bacillus methanolicus methanol dehydrogenase (MDH) is a decameric nicotinoprotein alcohol dehydrogenase (family III) with one Zn(2+) ion, one or two Mg(2+) ions, and a tightly bound cofactor NAD(H) per subunit. The Mg(2+) ions are essential for binding of cofactor NAD(H) in MDH. A B. methanolicus activator protein strongly stimulates the relatively low coenzyme NAD(+)-dependent MDH activity, involving hydrolytic removal of the NMN(H) moiety of cofactor NAD(H) (Kloosterman, H., Vrijbloed, J. W., and Dijkhuizen, L. (2002) J. Biol. Chem. 277, 34785-34792). Members of family III of NAD(P)-dependent alcohol dehydrogenases contain three unique, conserved sequence motifs (domains A, B, and C). Domain C is thought to be involved in metal binding, whereas the functions of domains A and B are still unknown. This paper provides evidence that domain A constitutes (part of) a new magnesium-dependent NAD(P)(H)-binding domain. Site-directed mutants D100N and K103R lacked (most of the) bound cofactor NAD(H) and had lost all coenzyme NAD(+)-dependent MDH activity. Also mutants G95A and S97G were both impaired in cofactor NAD(H) binding but retained coenzyme NAD(+)-dependent MDH activity. Mutant G95A displayed a rather low MDH activity, whereas mutant S97G was insensitive to activator protein but displayed "fully activated" MDH reaction rates. The various roles of these amino acid residues in coenzyme and/or cofactor NAD(H) binding in MDH are discussed.
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Affiliation(s)
- Harm J Hektor
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
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Hasona A, York SW, Yomano LP, Ingram LO, Shanmugam KT. Decreasing the level of ethyl acetate in ethanolic fermentation broths of Escherichia coli KO11 by expression of Pseudomonas putida estZ esterase. Appl Environ Microbiol 2002; 68:2651-9. [PMID: 12039716 PMCID: PMC123972 DOI: 10.1128/aem.68.6.2651-2659.2002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the fermentation of sugars to ethanol relatively high levels of an undesirable coproduct, ethyl acetate, are also produced. With ethanologenic Escherichia coli strain KO11 as the biocatalyst, the level of ethyl acetate in beer containing 4.8% ethanol was 192 mg liter(-1). Although the E. coli genome encodes several proteins with esterase activity, neither wild-type strains nor KO11 contained significant ethyl acetate esterase activity. A simple method was developed to rapidly screen bacterial colonies for the presence of esterases which hydrolyze ethyl acetate based on pH change. This method allowed identification of Pseudomonas putida NRRL B-18435 as a source of this activity and the cloning of a new esterase gene, estZ. Recombinant EstZ esterase was purified to near homogeneity and characterized. It belongs to family IV of lipolytic enzymes and contains the conserved catalytic triad of serine, aspartic acid, and histidine. As expected, this serine esterase was inhibited by phenylmethylsulfonyl fluoride and the histidine reagent diethylpyrocarbonate. The native and subunit molecular weights of the recombinant protein were 36,000, indicating that the enzyme exists as a monomer. By using alpha-naphthyl acetate as a model substrate, optimal activity was observed at pH 7.5 and 40 degrees C. The Km and Vmax for alpha-naphthyl acetate were 18 microM and 48.1 micromol. min(-1). mg of protein(-1), respectively. Among the aliphatic esters tested, the highest activity was obtained with propyl acetate (96 micromol. min(-1). mg of protein(-1)), followed by ethyl acetate (66 micromol. min(-1). mg of protein(-1)). Expression of estZ in E. coli KO11 reduced the concentration of ethyl acetate in fermentation broth (4.8% ethanol) to less than 20 mg liter(-1).
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Affiliation(s)
- Adnan Hasona
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611, USA
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Yuan W, Jia Y, Tian J, Snell KD, Müh U, Sinskey AJ, Lambalot RH, Walsh CT, Stubbe J. Class I and III polyhydroxyalkanoate synthases from Ralstonia eutropha and Allochromatium vinosum: characterization and substrate specificity studies. Arch Biochem Biophys 2001; 394:87-98. [PMID: 11566031 DOI: 10.1006/abbi.2001.2522] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Class I and III polyhydroxyalkanoate (PHA) synthases catalyze the conversion of beta-hydroxybutyryl coenzyme A (HBCoA) to polyhydroxybutyrate. The Class I PHA synthase from Ralstonia eutropha has been purified by numerous labs with reported specific activities that vary between 1 and 160 U/mg. An N-terminal (His)6-PHA synthase was constructed and purified with specific activity of 40 U/mg. The variable activity is shown to be related to the protein's propensity to aggregate and not to incomplete post-translational modification by coenzyme A and a phosphopantetheinyl transferase. The substrate specificities of this enzyme and the Class III PHA synthase from Allochromatium vinosum have been determined with nine analogs of varied chain length and branching, OH group position within the chain, and thioesters. The results suggest that in vitro, both PHA synthases are very specific and provide further support for their active site structural similarities. In vitro results differ from studies in vivo.
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Affiliation(s)
- W Yuan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Babel W, Ackermann JU, Breuer U. Physiology, regulation, and limits of the synthesis of poly(3HB). ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2001; 71:125-57. [PMID: 11217410 DOI: 10.1007/3-540-40021-4_4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The properties of poly(3-hydroxybutyrate) combined with the fact that it can be produced easily by numerous prokaryotes from renewable resources and even from potentially toxic waste products using well-known fermentation processes have generated keen interest in this biopolyester as a substitute for chemo-synthetic petroleum-derived polymers in many applications. However, the high price of poly(3HB) compared with the conventional synthetic materials currently in use has restricted its availability in a wide range of applications. If the economic viability of poly(3HB) production and its competitiveness are to be improved, more must be found out about the phenotypic optimization and the upper limits of bacterial systems as the factory of poly(3HB). In this chapter, two aspects of poly(3HB) are reviewed--poly(3HB) formation as a physiological response to external limitations and overcoming internal bottlenecks, and poly(3HB) as a commercially attractive polyester. From a physiological viewpoint, the ability to synthesize and degrade poly(3HB) is considered an investment in the future and provides organisms with a selective advantage. Poly(3HB) is presented as a strategic survival polymer, and it is shown that growth-associated synthesis is not as rare as reported. The influence of the efficiency and velocity of cell multiplication and product formation, of poly(3HB) content and of productivity on the overall yield, and finally on the economics of the whole process are discussed and evaluated from the technological or consumer's point of view. The specific production rate and poly(3HB) content appear to be more important than the yield coefficients.
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Affiliation(s)
- W Babel
- UFZ Umweltforschungszentrum Leipzig-Halle, Sektion Umweltmikrobiologie, Permoserstrasse 15, D-04318 Leipzig, Germany.
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Sudesh K, Abe H, Doi Y. Synthesis, structure and properties of polyhydroxyalkanoates: biological polyesters. Prog Polym Sci 2000. [DOI: 10.1016/s0079-6700(00)00035-6] [Citation(s) in RCA: 1569] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Bordetella pertussis, the etiologic agent of whooping cough, produces numerous toxins including pertussis toxin (PTX), adenylate cyclase toxin (AC), dermonecrotic toxin (DNT) and tracheal cytotoxin (TCT). PTX is composed of five different subunits organised in a typical A-B type structure of which the A part possesses an enzymatic ADP-ribosyltransferase activity and the B moiety expresses receptor-binding activity. The secretion of this toxin requires nine other genes (ptl) organised in an operon together with the five structural genes of PTX. To further characterise the genetic locus of this major virulence factor, we analysed the ptx/ptl upstream and downstream sequences. Comparison of these regions between three species of Bordetella (B. pertussis, Bordetella parapertussis and Bordetella bronchiseptica) revealed differences in the upstream region. Analysis of two strains of B. bronchiseptica naturally lacking the ptx genes showed that only the ptx/ptl genes were deleted in these strains, and that the upstream and downstream regions were conserved. Upstream of the PTX structural genes and the promoter, an open reading frame (bugT) was identified, the product of which is homologous with putative proteins from several other Gram-negative organisms. Detailed analysis of the genome of B. pertussis which is currently sequenced at the Sanger Centre revealed the presence of 90 genes coding for proteins homologous to BugT, which qualifies the bug gene family as the most populated one of Bordetella. These bug genes are located in various genetic environments, including the proximities of genes coding for other toxins, such as DNT and AC. The Bug proteins are highly conserved in terms of size and periodicity of predicted secondary structure elements, but have also a high variability in their amino acid composition reflected in their wide range of isoelectric points. The function of these genes which is currently unknown is under investigation. To characterise the expression and regulation of these genes, as well as of novel putative B. pertussis virulence factors, we designed a transcriptional fusion vector to be inserted in precise locations of the B. pertussis chromosome by homologous recombination. The reporter gene present in this vector allowed us to show that at least some of the bug genes are expressed.
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Affiliation(s)
- R Antoine
- INSERM U447, Institut Pasteur de Lille, France.
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Arai H, Ohishi T, Chang MY, Kudo T. Arrangement and regulation of the genes for meta-pathway enzymes required for degradation of phenol in Comamonas testosteroni TA441. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 7):1707-1715. [PMID: 10878134 DOI: 10.1099/00221287-146-7-1707] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Comamonas testosteroni TA441 degrades phenol by a meta-cleavage pathway after the occurrence of a spontaneous mutation that derepresses the aphKLMNOPQB operon encoding phenol hydroxylase and catechol 2,3-dioxygenase, the enzymes for the initial two steps of the degradation pathway. A gene cluster, aphCEFGHJI, encoding the meta-pathway enzymes for degradation of 2-hydroxymuconic semialdehyde (HMS) to TCA cycle intermediates was found downstream of the aphK operon. The upstream operon and the downstream gene cluster were found to be separated by two open reading frames of unknown function and an oppositely oriented aphT gene, which is similar to regulatory genes for ortho-cleavage of catechol or chlorinated catechols. A promoter assay using an aphC::lacZ transcriptional fusion plasmid revealed that the aphC promoter activity is induced by both phenol and HMS. The phenol-dependent induction was mediated by AphR and the HMS-dependent induction was mediated by AphT. The aphC promoter in strain TA441 was not silenced, unlike the cases of the aphK and aphR promoters, and was highly induced by HMS.
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Affiliation(s)
- Hiroyuki Arai
- Laboratory of Microbiology, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198, Japan1
| | - Tohru Ohishi
- Laboratory of Microbiology, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198, Japan1
| | - Mee Young Chang
- Laboratory of Microbiology, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198, Japan1
| | - Toshiaki Kudo
- Laboratory of Microbiology, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198, Japan1
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Liu SJ, Steinbüchel A. A novel genetically engineered pathway for synthesis of poly(hydroxyalkanoic acids) in Escherichia coli. Appl Environ Microbiol 2000; 66:739-43. [PMID: 10653745 PMCID: PMC91890 DOI: 10.1128/aem.66.2.739-743.2000] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new pathway to synthesize poly(hydroxyalkanoic acids) (PHA) was constructed by simultaneously expressing butyrate kinase (Buk) and phosphotransbutyrylase (Ptb) genes of Clostridium acetobutylicum and the two PHA synthase genes (phaE and phaC) of Thiocapsa pfennigii in Escherichia coli. The four genes were cloned into the BamHI and EcoRI sites of pBR322, and the resulting hybrid plasmid, pBPP1, conferred activities of all three enzymes to E. coli JM109. Cells of this recombinant strain accumulated PHAs when hydroxyfatty acids were provided as carbon sources. Homopolyesters of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB), or 4-hydroxyvalerate (4HV) were obtained from each of the corresponding hydroxyfatty acids. Various copolyesters of those hydroxyfatty acids were also obtained when two of these hydroxyfatty acids were fed at equal amounts: cells fed with 3HB and 4HB accumulated a copolyester consisting of 88 mol% 3HB and 12 mol% 4HB and contributing to 68.7% of the cell dry weight. Cells fed with 3HB and 4HV accumulated a copolyester consisting of 94 mol% 3HB and 6 mol% 4HV and contributing to 64.0% of the cell dry weight. Cells fed with 3HB, 4HB, and 4HV accumulated a terpolyester consisting of 85 mol% 3HB, 13 mol% 4HB, and 2 mol% 4HV and contributing to 68.4% of the cell dry weight.
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Affiliation(s)
- S J Liu
- Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, D-48149, Münster, Germany
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Lütke-Eversloh T, Steinbüchel A. Biochemical and molecular characterization of a succinate semialdehyde dehydrogenase involved in the catabolism of 4-hydroxybutyric acid in Ralstonia eutropha. FEMS Microbiol Lett 1999; 181:63-71. [PMID: 10564790 DOI: 10.1111/j.1574-6968.1999.tb08827.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
A succinate semialdehyde dehydrogenase gene (gabD) was identified to be disrupted in a transposon-induced mutant of Ralstonia eutropha exhibiting the phenotype 4-hydroxybutyric acid-leaky. The native gabD gene was cloned by colony hybridization using a homologous gabD-specific DNA probe. DNA sequencing revealed an 1452-bp open reading frame, and the deduced amino acid sequence showed strong similarities to NADP(+)-dependent succinate semialdehyde dehydrogenases from Escherichia coli, Rhizobium sp., Homo sapiens and Rattus norvegicus. The gabD gene was heterologously expressed in a recombinant E. coli strain harboring plasmid pSK::EE6.8. Similar to the molecular organization of the gab cluster in E. coli, additional genes encoding enzymes for the degradation of gamma-aminobutyrate are closely related to gabD in R. eutropha. Enzymatic studies indicated the existence of a second NAD(+)-dependent succinate semialdehyde dehydrogenase in R. eutropha.
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Affiliation(s)
- T Lütke-Eversloh
- Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, D-48149, Münster, Germany
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Ashiuchi M, Misono H. Biochemical evidence that Escherichia coli hyi (orf b0508, gip) gene encodes hydroxypyruvate isomerase. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1435:153-9. [PMID: 10561547 DOI: 10.1016/s0167-4838(99)00216-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We found a significant activity of hydroxypyruvate isomerase in Escherichia coli clone cells harboring an E. coli gene (called orf b0508 or gip), which is located downstream of the glyoxylate carboligase gene. We newly designated the gene hyi. The enzyme was purified from cell extracts of the E. coli clone. The enzyme had a molecular mass of 58 kDa and was composed of two identical subunits. The optimum pH for the isomerization of hydroxypyruvate was 6.8-7.2. The enzyme required no cofactor. It exclusively catalyzed the isomerization between hydroxypyruvate and tartronate semialdehyde. The apparent K(m) value for hydroxypyruvate was 12.5 mM. The amino acid sequence of E. coli hydroxypyruvate isomerase is highly similar to those of glyoxylate-induced proteins, Gip, found widely from prokaryotes to eukaryotes.
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Affiliation(s)
- M Ashiuchi
- Department of Bioresources Science, Faculty of Agriculture, Kochi University, Nankoku, Kochi, Japan
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Kimura H, Ohura T, Takeishi M, Nakamura S, Doi Y. Effective microbial production of poly(4-hydroxybutyrate) homopolymer byRalstonia eutropha H16. POLYM INT 1999. [DOI: 10.1002/(sici)1097-0126(199911)48:11<1073::aid-pi270>3.0.co;2-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Arai H, Yamamoto T, Ohishi T, Shimizu T, Nakata T, Kudo T. Genetic organization and characteristics of the 3-(3-hydroxyphenyl)propionic acid degradation pathway of Comamonas testosteroni TA441. MICROBIOLOGY (READING, ENGLAND) 1999; 145 ( Pt 10):2813-20. [PMID: 10537203 DOI: 10.1099/00221287-145-10-2813] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Comamonas testosteroni TA441 degrades 3-(3-hydroxyphenyl)propionate (3HPP) via the meta pathway. A gene cluster required for degradation of 3HPP was cloned from strain TA441 and sequenced. The genes encoding six catabolic enzymes, a flavin-type hydroxylase (mhpA), extradiol dioxygenase (mhpB), 2-keto-4-pentenoate hydratase (mhpD), acetaldehyde dehydrogenase (acylating) (mhpF), 4-hydroxy-2-ketovalerate aldolase (mhpE) and the meta cleavage compound hydrolase (mhpC), were found in this cluster, encoded in this order. mhpD and mhpF were separated by two genes, orf4 and orf5, which were not necessary for growth on 3HPP. The gene mhpR, encoding a putative transcriptional activator of the IcIR family, was located adjacent to mhpA in the opposite orientation. Disruption of the mhpB or mhpR genes affected growth on 3HPP or trans-3-hydroxycinnamate. The mhpB and mhpC gene products showed high specificity for 3-(2,3-dihydroxyphenyl)propionate (DHPP) and the meta cleavage compound produced from DHPP, respectively.
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Affiliation(s)
- H Arai
- Microbiology Laboratory, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, Japan
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41
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Henne A, Daniel R, Schmitz RA, Gottschalk G. Construction of environmental DNA libraries in Escherichia coli and screening for the presence of genes conferring utilization of 4-hydroxybutyrate. Appl Environ Microbiol 1999; 65:3901-7. [PMID: 10473393 PMCID: PMC99718 DOI: 10.1128/aem.65.9.3901-3907.1999] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental DNA libraries from three different soil samples were constructed. The average insert size was 5 to 8 kb and the percentage of plasmids with inserts was approximately 80%. The recombinant Escherichia coli strains (approximately 930,000) were screened for 4-hydroxybutyrate utilization. Thirty-six positive E. coli clones were obtained during the initial screen, and five of them contained a recombinant plasmid (pAH1 to pAH5) which conferred a stable 4-hydroxybutyrate-positive phenotype. These E. coli clones were studied further. All five were able to grow with 4-hydroxybutyrate as sole carbon and energy source and exhibited 4-hydroxybutyrate dehydrogenase activity in crude extracts. Sequencing of pAH5 revealed a gene homologous to the gbd gene of Ralstonia eutropha, which encodes a 4-hydroxybutyrate dehydrogenase. Two other genes (orf1 and orf6) conferring utilization of 4-hydroxybutyrate were identified during subcloning and sequencing of the inserts of pAH1 and pAH3. The deduced orf1 gene product showed similarities to members of the DedA family of proteins. The sequence of the deduced orf6 gene product harbors the fingerprint pattern of enoyl-coenzyme A hydratases/isomerases. The other sequenced inserts of the plasmids recovered from the positive clones revealed no significant similarity to any other gene or gene product whose sequence is available in the National Center for Biotechnology Information databases.
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Affiliation(s)
- A Henne
- Abteilung Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik der Georg-August-Universität, 37077 Göttingen, Germany
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Taguchi K, Aoyagi Y, Matsusaki H, Fukui T, Doi Y. Co-expression of 3-ketoacyl-ACP reductase and polyhydroxyalkanoate synthase genes induces PHA production in Escherichia coli HB101 strain. FEMS Microbiol Lett 1999; 176:183-90. [PMID: 10418145 DOI: 10.1111/j.1574-6968.1999.tb13660.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The Escherichia coli 3-ketoacyl-ACP reductase gene (fabGEc) was cloned using a PCR technique to investigate the metabolic link between fatty acid metabolism and polyhydroxyalkanoate (PHA) production. Three plasmids respectively harboring fabGEc and the poly-3-hydroxyalkanoate synthesis genes phaCAc and phaC1Ps from Aeromonas caviae and Pseudomonas sp. 61-3 respectively were constructed and introduced into E. coli HB101 strain. On a two-stage cultivation using dodecanoate as the sole carbon source, recombinant E. coli HB101 strains harboring fabGEc and phaC genes accumulated PHA copolymers (about 8 wt% of dry cell weight) consisting of several (R)-3-hydroxyalkanoate units of C4, C6, C8, and C10. It has been suggested that overexpression of the fabGEc gene leads to the supply of (R)-3-hydroxyacyl-CoA for PHA synthesis via fatty acid degradation.
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Affiliation(s)
- K Taguchi
- Polymer Chemistry Laboratory, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan
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43
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Choi MH, Yoon SC, Lenz RW. Production of poly(3-hydroxybutyric acid-co-4-hydroxybutyric acid) and poly(4-hydroxybutyric acid) without subsequent degradation by Hydrogenophaga pseudoflava. Appl Environ Microbiol 1999; 65:1570-7. [PMID: 10103252 PMCID: PMC91222 DOI: 10.1128/aem.65.4.1570-1577.1999] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A Hydrogenophaga pseudoflava strain was able to synthesize poly(3-hydroxybutyric acid-co-4-hydroxybutyric acid) [P(3HB-co-4HB)] having a high level of 4-hydroxybutyric acid monomer unit (4HB) from gamma-butyrolactone. In a two-step process in which the first step involved production of cells containing a minimum amount of poly(3-hydroxybutyric acid) [P(3HB)] and the second step involved polyester accumulation from the lactone, approximately 5 to 10 mol% of the 3-hydroxybutyric acid (3HB) derived from the first-step culture was unavoidably reincorporated into the polymer in the second cultivation step. Reincorporation of the 3HB units produced from degradation of the first-step residual P(3HB) was confirmed by high-resolution 13C nuclear magnetic resonance spectroscopy. In order to synthesize 3HB-free poly(4-hydroxybutyric acid) [P(4HB)] homopolymer, a three-stage cultivation technique was developed by adding a nitrogen addition step, which completely removed the residual P(3HB). The resulting polymer was free of 3HB. However, when the strain was grown on gamma-butyrolactone as the sole carbon source in a synthesis medium, a copolyester of P(3HB-co-4HB) containing 45 mol% 3HB was produced. One-step cultivation on gamma-butyrolactone required a rather long induction time (3 to 4 days). On the basis of the results of an enzymatic study performed with crude extracts, we suggest that the inability of cells to produce 3HB in the multistep culture was due to a low level of 4-hydroxybutyric acid (4HBA) dehydrogenase activity, which resulted in a low level of acetyl coenzyme A. Thus, 3HB formation from gamma-butyrolactone is driven by a high level of 4HBA dehydrogenase activity induced by long exposure to gamma-butyrolactone, as is the case for a one-step culture. In addition, intracellular degradation kinetics studies showed that P(3HB) in cells was completely degraded within 30 h of cultivation after being transferred to a carbon-free mineral medium containing additional ammonium sulfate, while P(3HB-co-4HB) containing 5 mol% 3HB and 95 mol% 4HB was totally inert in interactions with the intracellular depolymerases. Intracellular inertness could be a useful factor for efficient synthesis of the P(4HB) homopolymer and of 4HB-rich P(3HB-co-4HB) by the strain used in this study.
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Affiliation(s)
- M H Choi
- Biomaterials Science Laboratory, Division of Life Science, Gyeongsang National University, Chinju 660-701, Korea
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Braunegg G, Lefebvre G, Genser KF. Polyhydroxyalkanoates, biopolyesters from renewable resources: physiological and engineering aspects. J Biotechnol 1998; 65:127-61. [PMID: 9828458 DOI: 10.1016/s0168-1656(98)00126-6] [Citation(s) in RCA: 376] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Polyhdroxyalkanoates (PHAs), stored as bacterial reserve materials for carbon and energy, are biodegradable substitutes to fossil fuel plastics that can be produced from renewable raw materials. PHAs can be produced under controlled conditions by biotechnological processes. By varying the producing strains, substrates and cosubstrates, a number of polyesters can be synthesized which differ in monomer composition. By this means, PHAs with tailored interesting physical features can be produced. All of them are completely degradable to carbon dioxide and water through natural microbiological mineralization. Consequently, neither their production nor their use or degradation have a negative ecological impact. After a historical review, possibilities for the synthesis of novel PHAs applying different micro-organisms are discussed, and pathways of PHA synthesis and degradation are shown in detail for important PHA producers. This is followed by a discussion of the physiological role of the accumulation product in different micro-organisms. Detection, analysis, and extraction methods of PHAs from microbial biomass are shown, in addition to methods for polyester characterization. Strategies for PHA production under discontinuous and continuous regimes are discussed in detail in addition to the use of different cheap carbon sources from the point of view of different PHA producing strains. An outlook on PHA production by transgenic plants closes the review.
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Affiliation(s)
- G Braunegg
- Institut für Biotechnologie, TU Graz, Austria
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Pehrson JR, Fuji RN. Evolutionary conservation of histone macroH2A subtypes and domains. Nucleic Acids Res 1998; 26:2837-42. [PMID: 9611225 PMCID: PMC147630 DOI: 10.1093/nar/26.12.2837] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Histone macroH2A is an unusual core histone that contains a large non-histone region, and a region that resembles a full length H2A. We examined theconservation of this novel structural arrangement by cloning chicken macroH2A cDNAs and comparing them to their rat counterparts. The amino acid sequences of the two known macroH2A subtypes are >95% identical between these species despite evolutionary separation of approximately 300 million years. The H2A region of macroH2A is completely conserved, and thus is even more conserved than conventional H2A in these species. The origin of the non-histone domain was examined by comparing its sequence to proteins found in bacteria and RNA viruses. These comparisons indicate that this domain is derived from a gene that originated prior to the appearance of eukaryotes, and suggest that the non-histone region has retained the basic function of its ancestral gene.
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Affiliation(s)
- J R Pehrson
- University of Pennsylvania, Department of Animal Biology, School of Veterinary Medicine, Philadelphia, PA 19104-6048, USA.
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46
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Affiliation(s)
- B J Rawlings
- Department of Chemistry, University of Leicester, UK.
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47
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August PR, Tang L, Yoon YJ, Ning S, Müller R, Yu TW, Taylor M, Hoffmann D, Kim CG, Zhang X, Hutchinson CR, Floss HG. Biosynthesis of the ansamycin antibiotic rifamycin: deductions from the molecular analysis of the rif biosynthetic gene cluster of Amycolatopsis mediterranei S699. CHEMISTRY & BIOLOGY 1998; 5:69-79. [PMID: 9512878 DOI: 10.1016/s1074-5521(98)90141-7] [Citation(s) in RCA: 266] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The ansamycin class of antibiotics are produced by various Actinomycetes. Their carbon framework arises from the polyketide pathway via a polyketide synthase (PKS) that uses an unusual starter unit. Rifamycin (rif), produced by Amycolatopsis mediterranei, is the archetype ansamycin and it is medically important. Although its basic precursors (3-amino-5-hydroxy benzoic acid AHBA, and acetic and propionic acids) had been established, and several biosynthetic intermediates had been identified, very little was known about the origin of AHBA nor had the PKS and the various genes and enzymes that modify the initial intermediate been characterized. RESULTS A set of 34 genes clustered around the rifK gene encoding AHBA synthase were defined by sequencing all but 5 kilobases (kb) of a 95 kb contiguous region of DNA from A. mediterranei. The involvement of some of the genes in the biosynthesis of rifamycin B was examined. At least five genes were shown to be essential for the synthesis of AHBA, five genes were determined to encode the modular type I PKS that uses AHBA as the starter unit, and 20 or more genes appear to govern modification of the polyketide-derived framework, and rifamycin resistance and export. Putative regulatory genes were also identified. Disruption of the PKS genes at the end of rifA abolished rifamycin B production and resulted in the formation of P8/1-OG, a known shunt product of rifamycin biosynthesis, whereas disruption of the orf6 and orf9 genes, which may encode deoxysugar biosynthesis enzymes, had no apparent effect. CONCLUSIONS Rifamycin production in A. mediterranei is governed by a single gene cluster consisting of structural, resistance and export, and regulatory genes. The genes characterized here could be modified to produce novel forms of the rifamycins that may be effective against rifamycin-resistant microorganisms.
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Affiliation(s)
- P R August
- Department of Chemistry, University of Washington, Seattle 98195-1700, USA
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Valentin HE, Dennis D. Production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) in recombinant Escherichia coli grown on glucose. J Biotechnol 1997; 58:33-8. [PMID: 9335177 DOI: 10.1016/s0168-1656(97)00127-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A recombinant Escherichia coli strain has been developed that produces poly(3-hydroxybutyrate-co-4-hydroxybutyrate) when grown in complex medium containing glucose. This has been accomplished by introducing into E. coli DH5 alpha separate plasmids harboring the polyhydroxyalkanoate (PHA) biosynthesis genes from Ralstonia eutropha (formerly named Alcaligenes eutrophus) and the succinate degradation genes from Clostridium kluyveri, respectively. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) levels reached 50% of the cell dry weight and contained up to 2.8 mol.% 4-hydroxybutyrate. The molecular weight of the polymer was 1.8 x 10(6).
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Affiliation(s)
- H E Valentin
- Department of Biology, James Madison University, Harrisonburg, VA 22807, USA.
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Hein S, Söhling B, Gottschalk G, Steinbüchel A. Biosynthesis of poly(4-hydroxybutyric acid) by recombinant strains of Escherichia coli. FEMS Microbiol Lett 1997; 153:411-8. [PMID: 9271870 DOI: 10.1111/j.1574-6968.1997.tb12604.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The aim of this study was the production of the homopolyester poly(4-hydroxybutyric acid) (poly(4HB)) with recombinant strains of Escherichia coli. Wild-type strains and other widely used non-recombinant strains of E. coli are not able to produce polyhydroxyalkanoic acids (PHA) as storage compounds and cannot utilize 4-hydroxybutyric acid as sole carbon source. Accordingly, hybrid plasmids of pBluescript vectors were constructed which harbored the Alcaligenes eutrophus PHA synthase gene (phaC) and the Clostridium kluyveri orfZ putatively encoding a 4-hydroxybutyric acid-coenzyme A transferase. A 3.5-kb genomic SmaI/ApaI fragment from A. eutrophus, which comprises phaC, and a 1.8-kb genomic ApaI/EcoRI fragment from C kluyveri, which contained orfZ, were inserted into the SmaI and EcoRI sites of the vectors pKS- and pSK-, respectively. The two resulting plasmids pSKSE5.3 and pKSSE5.3 comprising phaC and orfZ colinear or antilinear to lacZ, respectively, were transformed into E. coli XL1-Blue. Recombinant strains synthesized the homopolyester poly(4HB), when the cells were cultivated in Luria-Bertani broth and if glucose and 4-hydroxybutyric acid were provided as carbon sources. If glucose was omitted, a copolyester of 3-hydroxybutyric acid and 4-hydroxybutyric acid was accumulated. The homopolyester poly(4HB) was also accumulated during cultivation of these strains in M9 mineral salts medium containing glucose plus 4-hydroxybutyric acid as carbon sources. Poly(4HB) could amount up to approximately 80% (w/w) of the cell dry matter if E. coli XL1-Blue harboring pKSSE5.3 was cultivated in M9 mineral salts medium and if the cultures were not sufficiently supplied with oxygen. 4HB was also incorporated into PHA if gamma-butyrolactone was used as carbon source. If levulinic acid, 4-hydroxyvaleric acid or gamma-valerolactone were used as carbon sources, only very low amounts of PHA were accumulated which did not contain 4-hydroxyalkanoic acids as constituents.
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Affiliation(s)
- S Hein
- Institut für Mikrobiologie der Westfälischen Wilhelms-Universität Münster, Germany
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Wölf E, Achatz G, Imhoff JF, Schiltz E, Weckesser J, Lamers MC. Porin from the halophilic species Ectothiorhodospira vacuolata: cloning, structure of the gene and comparison with other porins. Gene 1997; 191:225-32. [PMID: 9218724 DOI: 10.1016/s0378-1119(97)00065-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The gene coding for the anion-specific porin of the halophilic eubacterium Ectothiorhodospira (Ect.) vacuolata was cloned and sequenced, the first such gene so analyzed from a purple sulfur bacterium. It encodes a precursor protein consisting of 374 amino acid (aa)-residues including a signal peptide of 22-aa residues. Comparison with aa sequences of porins from several other members of the Proteobacteria revealed little homology. Only two regions showed local homology with the previously sequenced porins of Neisseria species, Comamonas acidovorans, Bordetella pertussis, Alcaligenes eutrophus, and Burkholderia cepacia. Genomic Southern blot hybridization studies were carried out with a probe derived from the 5' end of the gene coding for the porin of Ect. vacuolata. Two related species, Ect. haloalkaliphila and Ect. shaposhnikovii, exhibited a clear signal, while the extremely halophilic bacterium Halorhodospira (Hlr.) halophila (formerly Ect. halophila) did not show any cross-hybridization even at low stringency. This result is in good accordance with a recently proposed reassignment within the family Ectothiorhodospiraceae, which included the separation of the extremely halophilic species into the new genus Halorhodospira.
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Affiliation(s)
- E Wölf
- Institut für Biologie II-Mikrobiologie, Albert-Ludwigs-Universitat, Freiburg, Germany
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