1
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Casolari F, Alrashdi S, Carr R, Deng H. Exploring a Streptomyces wax synthase using acyl-SNACs as donor substrates. RSC Chem Biol 2023; 4:742-747. [PMID: 37799584 PMCID: PMC10549239 DOI: 10.1039/d3cb00107e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/09/2023] [Indexed: 10/07/2023] Open
Abstract
The demand of fragrance and food industries for short/branched wax esters is increasing due to their rich scent and low toxicity. Wax synthase and acyl-CoA:diacylglycerol O-acyltransferase (WS/DGAT) are a family of bacterial enzymes capable of catalysing the production of wax esters. Here, we report that a WS/DGAT from Streptomyces coelicolor is able to mediate the reactions between alcohol acceptors and synthetic acyl-donor mimics, acyl-SNACs. The enzyme displayed considerable substrate tolerance towards acyl-donors with structural diversity. Structural modelling-guided site directed mutagenesis resulted in a variant, L25F, the catalytic efficiency of which was improved toward aromatic, short-linear, and branched acyl-donors compared to the wild type.
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Affiliation(s)
- Federica Casolari
- Department of Chemistry, University of Aberdeen Aberdeen AB24 3UE UK
| | - Saad Alrashdi
- Department of Chemistry, University of Aberdeen Aberdeen AB24 3UE UK
- College of Science and Arts in Gurayat, Jouf University King Khaled Road Saudi Arabia
| | | | - Hai Deng
- Department of Chemistry, University of Aberdeen Aberdeen AB24 3UE UK
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2
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Valle-Rodríguez JO, Siewers V, Nielsen J, Shi S. Directed evolution of a wax ester synthase for production of fatty acid ethyl esters in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2023; 107:2921-2932. [PMID: 36976306 DOI: 10.1007/s00253-023-12466-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/29/2023]
Abstract
Wax ester synthases (WSs) utilize a fatty alcohol and a fatty acyl-coenzyme A (activated fatty acid) to synthesize the corresponding wax ester. There is much interest in developing novel cell factories that can produce shorter esters, e.g., fatty acid ethyl esters (FAEEs), with properties similar to biodiesel in order to use these as transportation fuels. However, ethanol is a poor substrate for WSs, and this may limit the biosynthesis of FAEEs. Here, we implemented a random mutagenesis approach to enhance the catalytic efficiency of a WS from Marinobacter hydrocarbonoclasticus (MhWS2, encoded by the ws2 gene). Our selection system was based on FAEE formation serving as a detoxification mechanism for excessive oleate, where high WS activity was essential for a storage-lipid free yeast to survive. A random mutagenesis library of ws2 was used to transform the storage-lipid free yeast, and mutants could be selected by plating the transformants on oleate containing plates. The variants encoding WS with improved activity were sequenced, and an identified point mutation translated into the residue substitution at position A344 was discovered to substantially increase the selectivity of MhWS2 toward ethanol and other shorter alcohols. Structural modeling indicated that an A344T substitution might affect the alcohol selectivity due to change of both steric effects and polarity changes near the active site. This work not only provides a new WS variant with altered selectivity to shorter alcohols but also presents a new high-throughput selection system to isolate WSs with a desired selectivity. KEY POINTS: • The work provides WS variants with altered substrate preference for shorter alcohols • A novel method was developed for directed evolution of WS of desired selectivity.
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Affiliation(s)
| | - Verena Siewers
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark.
| | - Shuobo Shi
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
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3
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Bird LJ, Mickol RL, Eddie BJ, Thakur M, Yates MD, Glaven SM. Marinobacter: A case study in bioelectrochemical chassis evaluation. Microb Biotechnol 2023; 16:494-506. [PMID: 36464922 PMCID: PMC9948230 DOI: 10.1111/1751-7915.14170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/28/2022] [Accepted: 11/03/2022] [Indexed: 12/08/2022] Open
Abstract
The junction of bioelectrochemical systems and synthetic biology opens the door to many potentially groundbreaking technologies. When developing these possibilities, choosing the correct chassis organism can save a great deal of engineering effort and, indeed, can mean the difference between success and failure. Choosing the correct chassis for a specific application requires a knowledge of the metabolic potential of the candidate organisms, as well as a clear delineation of the traits, required in the application. In this review, we will explore the metabolic and electrochemical potential of a single genus, Marinobacter. We will cover its strengths, (salt tolerance, biofilm formation and electrochemical potential) and weaknesses (insufficient characterization of many strains and a less developed toolbox for genetic manipulation) in potential synthetic electromicrobiology applications. In doing so, we will provide a roadmap for choosing a chassis organism for bioelectrochemical systems.
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Affiliation(s)
- Lina J Bird
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA
| | - Rebecca L Mickol
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA
| | - Brian J Eddie
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA
| | - Meghna Thakur
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA.,College of Science, George Mason University, Fairfax, Virginia, USA
| | - Matthew D Yates
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA
| | - Sarah M Glaven
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, District of Columbia, USA
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4
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Vollheyde K, Kühnel K, Lambrecht F, Kawelke S, Herrfurth C, Feussner I. Crystal Structure of the Bifunctional Wax Synthase 1 from Acinetobacter baylyi Suggests a Conformational Change upon Substrate Binding and Formation of Additional Substrate Binding Sites. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katharina Vollheyde
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077 Goettingen, Germany
| | - Karin Kühnel
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, D-37077 Goettingen, Germany
| | - Felix Lambrecht
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077 Goettingen, Germany
| | - Steffen Kawelke
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077 Goettingen, Germany
| | - Cornelia Herrfurth
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077 Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, D-37077 Goettingen, Germany
| | - Ivo Feussner
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077 Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, D-37077 Goettingen, Germany
- International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, D-37077 Goettingen, Germany
- Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, D-37077 Goettingen, Germany
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5
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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6
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Domergue F, Miklaszewska M. The production of wax esters in transgenic plants:
towards a sustainable source of bio-lubricants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2817-2834. [PMID: 35560197 PMCID: PMC9113324 DOI: 10.1093/jxb/erac046] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 02/03/2022] [Indexed: 05/08/2023]
Abstract
Wax esters are high-value compounds used as feedstocks for the production of lubricants, pharmaceuticals, and cosmetics. Currently, they are produced mostly from fossil reserves using chemical synthesis, but this cannot meet increasing demand and has a negative environmental impact. Natural wax esters are also obtained from Simmondsia chinensis (jojoba) but comparably in very low amounts and expensively. Therefore, metabolic engineering of plants, especially of the seed storage lipid metabolism of oil crops, represents an attractive strategy for renewable, sustainable, and environmentally friendly production of wax esters tailored to industrial applications. Utilization of wax ester-synthesizing enzymes with defined specificities and modulation of the acyl-CoA pools by various genetic engineering approaches can lead to obtaining wax esters with desired compositions and properties. However, obtaining high amounts of wax esters is still challenging due to their negative impact on seed germination and yield. In this review, we describe recent progress in establishing non-food-plant platforms for wax ester production and discuss their advantages and limitations as well as future prospects.
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Affiliation(s)
- Frédéric Domergue
- Univ. Bordeaux, CNRS, LBM, UMR 5200, F-33140 Villenave d’Ornon, France
| | - Magdalena Miklaszewska
- Department of Functional and Evolutionary Ecology, Division of Molecular Systems Biology (MOSYS), Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
- Department of Plant Physiology and Biotechnology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
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7
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Mancipe NC, Mulliner KM, Plunkett MH, Barney BM. Canvasing the Substrate-Binding Pockets of the Wax Ester Synthase. Biochemistry 2022; 61:922-932. [PMID: 35507417 DOI: 10.1021/acs.biochem.2c00076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biosynthesis of wax esters and triglycerides in bacteria is accomplished through the action of the wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT or wax ester synthase). A hallmark of these enzymes is the broad substrate profile that accepts alcohols, diglycerides, and fatty acyl-CoAs of various carbon chain lengths and degrees of branching. These enzymes have a broad biotechnological potential due to their role in producing high-value lipids or simple fuels similar to biodiesel through biosynthetic routes. Recently, a crystal structure was solved for the wax ester synthase from Marinobacter aquaeolei VT8 (Maqu_0168), providing a much clearer picture of the architecture of this enzyme and enabling a more precise analysis of the important structural features of the protein. In this work, we used the structure to canvas amino acids lining the proposed substrate-binding pockets and tested the effects of exchanging specific residues on the substrate profiles. We also developed an approach to better probe the residues that alter fatty acyl-CoA selectivity, which has proven more difficult to investigate. Our findings provide an improved blueprint for future efforts to understand how these enzymes position substrates for catalysis and to tailor or improve these enzymes in future biosynthetic schemes.
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Affiliation(s)
- Natalia Calixto Mancipe
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
| | - Kalene M Mulliner
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
| | - Mary H Plunkett
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108, United States
| | - Brett M Barney
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States.,BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108, United States
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8
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Zhang Y, Guo X, Yang H, Shi S. The Studies in Constructing Yeast Cell Factories for the Production of Fatty Acid Alkyl Esters. Front Bioeng Biotechnol 2022; 9:799032. [PMID: 35087801 PMCID: PMC8787340 DOI: 10.3389/fbioe.2021.799032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/19/2021] [Indexed: 12/25/2022] Open
Abstract
Fatty acid alkyl esters have broad applications in biofuels, lubricant formulas, paints, coatings, and cosmetics. Traditionally, these esters are mostly produced through unsustainable and energy-intensive processes. In contrast, microbial production of esters from renewable and sustainable feedstocks may provide a promising alternative and has attracted widespread attention in recent years. At present, yeasts are used as ideal hosts for producing such esters, due to their availability for high-density fermentation, resistance to phage infection, and tolerance against toxic inhibitors. Here, we summarize recent development on the biosynthesis of alkyl esters, including fatty acid ethyl esters (FAEEs), fatty acid short-branched chain alkyl esters (FASBEs), and wax esters (WEs) by various yeast cell factories. We focus mainly on the enzyme engineering strategies of critical wax ester synthases, and the pathway engineering strategies employed for the biosynthesis of various ester products. The bottlenecks that limit productivity and their potential solutions are also discussed in this review.
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Affiliation(s)
- Yang Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.,CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiao Guo
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Huaiyi Yang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuobo Shi
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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9
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Roulet J, Galván V, Lara J, Salazar MO, Cholich V, Gramajo H, Arabolaza A. Modification of PapA5 acyltransferase substrate selectivity for optimization of short-chain alcohol-derived multimethyl-branched ester production in Escherichia coli. Appl Microbiol Biotechnol 2020; 104:8705-8718. [PMID: 32910267 DOI: 10.1007/s00253-020-10872-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 08/31/2020] [Indexed: 11/30/2022]
Abstract
Plant waxes are interesting substitutes of fossil-derived compounds; however, their limited sources and narrow structural diversity prompted the development of microbial platforms to produce esters with novel chemical structures and properties. One successful strategy was the heterologous expression of the mycocerosic polyketide synthase-based biosynthetic pathway (MAS-PKS, PapA5 and FadD28 enzymes) from Mycobacterium tuberculosis in Escherichia coli. This recombinant strain has the ability to produce a broad spectrum of multimethyl-branched long-chain esters (MBE) with novel chemical structures and high oxidation stability. However, one limitation of this microbial platform was the low yields obtained for MBE derived of short-chain alcohols. In an attempt to improve the titers of the short-chain alcohol-derived MBE, we focused on the PapA5 acyltransferase-enzyme that catalyzes the ester formation reaction. Specific amino acid residues located in the two-substrate recognition channels of this enzyme were identified, rationally mutated, and the corresponding mutants characterized both in vivo and in vitro. The phenylalanine located at 331 position in PapA5 (F331) was found to be a key residue that when substituted by other bulky and aromatic or bulky and polar amino acid residues (F331W, F331Y or F331H), gave rise to PapA5 mutants with improved bioconversion efficiency; showing in average, 2.5 higher yields of short-chain alcohol-derived MBE compared with the wild-type enzyme. Furthermore, two alternative pathways for synthetizing ethanol were engineered into the MBE producer microorganism, allowing de novo production of ethanol-derived MBE at levels comparable with those obtained by the external supply of this alcohol. KEY POINTS: • Mutation in channel 2 changes PapA5 acyltransferase bioconversion efficiency. • Improved production of short-chain alcohol derived multimethyl-branched esters. • Establishing ethanologenic pathways for de novo production of ethanol derived MBE. • Characterization of a novel phenylethanol-derived MBE.
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Affiliation(s)
- Julia Roulet
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Virginia Galván
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Julia Lara
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Mario O Salazar
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Valeria Cholich
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Hugo Gramajo
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
| | - Ana Arabolaza
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
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10
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Yang Y, Zhou Z, Li Y, Lv Y, Yang D, Yang S, Wu J, Li X, Gu Z, Sun X, Yang Y. Uncovering the role of a positive selection site of wax ester synthase/diacylglycerol acyltransferase in two closely related Stipa species in wax ester synthesis under drought stress. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4159-4170. [PMID: 32309855 PMCID: PMC7475244 DOI: 10.1093/jxb/eraa194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/17/2020] [Indexed: 06/02/2023]
Abstract
Natural selection drives local adaptations of species to biotic or abiotic environmental stresses. As a result, adaptive phenotypic divergence can evolve among related species living in different habitats. However, the genetic foundation of this divergence process remains largely unknown. Two closely related alpine grass species, Stipa capillacea and Stipa purpurea, are distributed in different rainfall regions of northern Tibet. Here, we analyzed the drought tolerance of these two closely related Stipa species, and found that S. purpurea was more resistance to drought stress than S. capillacea. To further understand the genetic diversity behind their adaptation to drought environments, a comprehensive gene repertoire was generated using PacBio isoform and Illumina RNA sequencing technologies. Bioinformatics analyses revealed that differential transcripts were mainly enriched in the wax synthetic pathway, and a threonine residue at position 239 of WSD1 was identified as having undergone positive selection in S. purpurea. Using heterologous expression in the Saccharomyces cerevisiae mutant H1246, site-directed mutagenesis studies demonstrated that a positive selection site results in changes to the wax esters profile. This difference may play an important role in S. purpurea in response to drought conditions, indicating that S. purpurea has evolved specific strategies involving its wax biosynthetic pathway as part of its long-term adaptation to the Qinghai-Tibet Plateau.
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Affiliation(s)
- Yunqiang Yang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Zhili Zhou
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Yan Li
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yanqiu Lv
- College of Life Sciences, Changchun Normal University, Changchun, China
| | - Danni Yang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shihai Yang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Jianshuang Wu
- Functional Biodiversity, Dahlem Center of Plant Sciences, Free University of Berlin, Berlin, Germany
| | - Xiong Li
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Zhijia Gu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
| | - Xudong Sun
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Yongping Yang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, China
- Plant Germplasm and Genomics Center, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
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11
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Vollheyde K, Yu D, Hornung E, Herrfurth C, Feussner I. The Fifth WS/DGAT Enzyme of the Bacterium Marinobacter aquaeolei VT8. Lipids 2020; 55:479-494. [PMID: 32434279 DOI: 10.1002/lipd.12250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/09/2020] [Accepted: 04/30/2020] [Indexed: 12/19/2022]
Abstract
Wax esters (WE) belong to the class of neutral lipids. They are formed by an esterification of a fatty alcohol and an activated fatty acid. Dependent on the chain length and desaturation degree of the fatty acid and the fatty alcohol moiety, WE can have diverse physicochemical properties. WE derived from monounsaturated long-chain acyl moieties are of industrial interest due to their very good lubrication properties. Whereas WE were obtained in the past from spermaceti organs of the sperm whale, industrial WE are nowadays mostly produced chemically from fossil fuels. In order to produce WE more sustainably, attempts to produce industrial WE in transgenic plants are steadily increasing. To achieve this, different combinations of WE producing enzymes are expressed in developing Arabidopsis thaliana or Camelina sativa seeds. Here we report the identification and characterization of a fifth wax synthase from the organism Marinobacter aquaeolei VT8, MaWSD5. It belongs to the class of bifunctional wax synthase/acyl-CoA:diacylglycerol O-acyltransferases (WSD). The protein was purified to homogeneity. In vivo and in vitro substrate analyses revealed that MaWSD5 is able to synthesize WE but no triacylglycerols. The protein produces WE from saturated and monounsaturated mid- and long-chain substrates. Arabidopsis thaliana seeds expressing a fatty acid reductase from Marinobacter aquaeolei VT8 and MaWSD5 produce WE. Main WE synthesized are 20:1/18:1 and 20:1/20:1. This makes MaWSD5 a suitable candidate for industrial WE production in planta.
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Affiliation(s)
- Katharina Vollheyde
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077, Goettingen, Germany
| | - Dan Yu
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077, Goettingen, Germany
| | - Ellen Hornung
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077, Goettingen, Germany
| | - Cornelia Herrfurth
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077, Goettingen, Germany.,Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, D-37077, Goettingen, Germany
| | - Ivo Feussner
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077, Goettingen, Germany.,Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, D-37077, Goettingen, Germany.,Department for Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077, Goettingen, Germany
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Yan Q, Pfleger BF. Revisiting metabolic engineering strategies for microbial synthesis of oleochemicals. Metab Eng 2019; 58:35-46. [PMID: 31022535 DOI: 10.1016/j.ymben.2019.04.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/20/2019] [Accepted: 04/21/2019] [Indexed: 02/06/2023]
Abstract
Microbial production of oleochemicals from renewable feedstocks remains an attractive route to produce high-energy density, liquid transportation fuels and high-value chemical products. Metabolic engineering strategies have been applied to demonstrate production of a wide range of oleochemicals, including free fatty acids, fatty alcohols, esters, olefins, alkanes, ketones, and polyesters in both bacteria and yeast. The majority of these demonstrations synthesized products containing long-chain fatty acids. These successes motivated additional effort to produce analogous molecules comprised of medium-chain fatty acids, molecules that are less common in natural oils and therefore of higher commercial value. Substantial progress has been made towards producing a subset of these chemicals, but significant work remains for most. The other primary challenge to producing oleochemicals in microbes is improving the performance, in terms of yield, rate, and titer, of biocatalysts such that economic large-scale processes are feasible. Common metabolic engineering strategies include blocking pathways that compete with synthesis of oleochemical building blocks and/or consume products, pulling flux through pathways by removing regulatory signals, pushing flux into biosynthesis by overexpressing rate-limiting enzymes, and engineering cells to tolerate the presence of oleochemical products. In this review, we describe the basic fundamentals of oleochemical synthesis and summarize advances since 2013 towards improving performance of heterotrophic microbial cell factories.
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Affiliation(s)
- Qiang Yan
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Wisconsin-Madison, Madison, WI 53706, United States; Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Petronikolou N, Nair SK. Structural and Biochemical Studies of a Biocatalyst for the Enzymatic Production of Wax Esters. ACS Catal 2018; 8:6334-6344. [PMID: 31559109 DOI: 10.1021/acscatal.8b00787] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Wax esters are high-value products whose enzymatic synthesis is of increasing biotechnological interest. The fabrication of cell factories that mass-produce wax esters may provide a facile route towards a sustainable, and environment-friendly approach to a large-scale process for this commodity chemical. An expedient route for wax-ester biocatalysis may be facilitated by the action of enzymes termed wax ester synthases/diacylglycerol acyltransferases (WS/DGAT), which produce wax esters using fatty acids and alcohols as a precursor. In this work, we report the structure for a member of the WS/DGAT superfamily. The structural data in conjunction with bioinformatics and mutational analyses allowed us to identify the substrate binding pockets, and residues that may be important for catalysis. Using this information as a guide, we generated a mutant with preference towards shorter acyl-substrates. This study demonstrates the efficacy of a structure-guided engineering effort towards a WS/DGAT variant with preference towards wax esters of desired lengths.
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Microbial synthesis of medium-chain chemicals from renewables. Nat Biotechnol 2017; 35:1158-1166. [PMID: 29220020 DOI: 10.1038/nbt.4022] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 10/31/2017] [Indexed: 12/28/2022]
Abstract
Linear, medium-chain (C8-C12) hydrocarbons are important components of fuels as well as commodity and specialty chemicals. As industrial microbes do not contain pathways to produce medium-chain chemicals, approaches such as overexpression of endogenous enzymes or deletion of competing pathways are not available to the metabolic engineer; instead, fatty acid synthesis and reversed β-oxidation are manipulated to synthesize medium-chain chemical precursors. Even so, chain lengths remain difficult to control, which means that purification must be used to obtain the desired products, titers of which are typically low and rarely exceed milligrams per liter. By engineering the substrate specificity and activity of the pathway enzymes that generate the fatty acyl intermediates and chain-tailoring enzymes, researchers can boost the type and yield of medium-chain chemicals. Development of technologies to both manipulate chain-tailoring enzymes and to assay for products promises to enable the generation of g/L yields of medium-chain chemicals.
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