1
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Ahrens H, Barber DM, Bojack G, Bollenbach-Wahl B, Churchman L, Getachew R, Helmke H, Hohmann S, Laber B, Lange G, Rees S, Reingruber AM, Schmutzler D, Frackenpohl J. Synthesis and biological profile of substituted hexahydrofuro[3,4-b]furans, a novel class of bicyclic acyl-acyl carrier protein (ACP) thioesterase inhibitors. PEST MANAGEMENT SCIENCE 2024. [PMID: 39104300 DOI: 10.1002/ps.8357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 08/07/2024]
Abstract
BACKGROUND Weed control is a significant challenge for farmers around the globe. Of the various methods available for combatting weeds, small molecules remain the most effective and versatile technology to date. In the search for novel chemical entities with new modes of action toward herbicide-resistant weeds, we have investigated hexahydrofuro[3,4-b]furan-based acyl-acyl carrier protein (ACP) thioesterase inhibitors inspired by X-ray co-crystal structure-based modeling studies. RESULTS By exploiting scaffold hopping concepts and molecular modeling studies we were able to identify new hexahydrofuro[3,4-b]furan-based lead structures showing promising activity in vivo against commercially important grass weeds in line with strong target affinity. CONCLUSION The present work covers a series of novel herbicidal lead structures that possess a hexahydrofuro[3,4-b]furan scaffold as a structural key feature, carrying ortho-substituted aryloxy side chains. Based on an optimized synthetic approach a broad structure-activity relationship (SAR) study was carried out. The new compounds emerging from our modeling-inspired structural variations show good acyl-ACP thioesterase inhibition in line with promising initial herbicidal activity. Glasshouse trials showed that the hexahydrofuro[3,4-b]furans outlined herein display good control of cold and warm season grass-weed species in pre-emergence application. Remarkably, some of the novel acyl-ACP thioesterase-inhibitors also showed promising efficacy against warm season weeds that are difficult to control. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Hartmut Ahrens
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - David M Barber
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Guido Bojack
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Birgit Bollenbach-Wahl
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Luke Churchman
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Rahel Getachew
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Hendrik Helmke
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Sabine Hohmann
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Bernd Laber
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Gudrun Lange
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Shaun Rees
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Anna M Reingruber
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Dirk Schmutzler
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
| | - Jens Frackenpohl
- Research and Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt am Main, Germany
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2
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Yang H, Gao J, Peng X, Han Y. Application of synthetic biology strategies to promote biosynthesis of fatty acids and their derivatives. ADVANCES IN APPLIED MICROBIOLOGY 2024; 128:83-104. [PMID: 39059844 DOI: 10.1016/bs.aambs.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Fatty acids and their derivatives are indispensable biomolecules in all organisms, and can be used as intermediates in the synthesis of pharmaceuticals, biofuels and pesticides, and thus their demand has increased dramatically in recent years. In addition to serving as structural components of cell membranes and metabolic energy, fatty acids and their derivatives can also be used as signal transduction and regulatory bioactive molecules to regulate cell functions. Biosynthesis of fatty acids and their derivatives through microbial catalysis provides green and alternative options to meet the goal. However, the low biosynthetic titer of fatty acids and their derivatives limits their industrial production and application. In this review, we first summarize the metabolic pathways and related enzymes of fatty acids and their derivatives biosynthesis. Then, the strategies and research progress of biosynthesis of fatty acids and derivatives through metabolic and enzyme engineering were reviewed. The biosynthesis of saturated fatty acids (medium chain fatty acids and long chain fatty acids), bioactive fatty acids (PUFAs, oxylipins, ether lipids), and their derivatives with microbial and enzymatic catalysis were respectively summarized. Finally, synthetic biology strategies to improve fatty acids and their derivatives production through enzyme rational design, carbon metabolism flux, cofactors balance, and metabolic pathways design were discussed. The review provides references and prospects for fatty acids and their derivatives biosynthesis and industrial production.
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Affiliation(s)
- Haiqian Yang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Jie Gao
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, P.R. China
| | - Xiaowei Peng
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Yejun Han
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China.
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3
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Jing F, Chen K, Yandeau-Nelson MD, Nikolau BJ. Machine learning model of the catalytic efficiency and substrate specificity of acyl-ACP thioesterase variants generated from natural and in vitro directed evolution. Front Bioeng Biotechnol 2024; 12:1379121. [PMID: 38665811 PMCID: PMC11043601 DOI: 10.3389/fbioe.2024.1379121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
Modulating the catalytic activity of acyl-ACP thioesterase (TE) is an important biotechnological target for effectively increasing flux and diversifying products of the fatty acid biosynthesis pathway. In this study, a directed evolution approach was developed to improve the fatty acid titer and fatty acid diversity produced by E. coli strains expressing variant acyl-ACP TEs. A single round of in vitro directed evolution, coupled with a high-throughput colorimetric screen, identified 26 novel acyl-ACP TE variants that convey up to a 10-fold increase in fatty acid titer, and generate altered fatty acid profiles when expressed in a bacterial host strain. These in vitro-generated variant acyl-ACP TEs, in combination with 31 previously characterized natural variants isolated from diverse phylogenetic origins, were analyzed with a random forest classifier machine learning tool. The resulting quantitative model identified 22 amino acid residues, which define important structural features that determine the catalytic efficiency and substrate specificity of acyl-ACP TE.
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Affiliation(s)
- Fuyuan Jing
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
- Center for Metabolic Biology, Iowa State University, Ames, IA, United States
- Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, United States
| | - Keting Chen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Marna D. Yandeau-Nelson
- Center for Metabolic Biology, Iowa State University, Ames, IA, United States
- Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, United States
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Basil J. Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
- Center for Metabolic Biology, Iowa State University, Ames, IA, United States
- Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, United States
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4
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Asmus E, Barber DM, Bojack G, Bollenbach-Wahl B, Brown RW, Döller U, Freigang J, Gatzweiler E, Getachew R, Heinemann I, Hohmann S, Ko KY, Laber B, Lange G, Mattison RL, Minn K, Müller T, Petry T, Reingruber AM, Schmutzler D, Svejda A, Frackenpohl J. Discovery and optimization of spirocyclic lactams that inhibit acyl-ACP thioesterase. PEST MANAGEMENT SCIENCE 2024. [PMID: 38334233 DOI: 10.1002/ps.8015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/09/2024] [Indexed: 02/10/2024]
Abstract
BACKGROUND There are various methods to control weeds, that represent considerable challenges for farmers around the globe, although applying small molecular compounds is still the most effective and versatile technology to date. In the search for novel chemical entities with new modes-of-action that can control weeds displaying resistance, we have investigated two spirocyclic classes of acyl-ACP thioesterase inhibitors based on X-ray co-crystal structures and subsequent modelling studies. RESULTS By exploiting scaffold-hopping and isostere concepts, we were able to identify new spirolactam-based lead structures showing promising activity in vivo against commercially important grass weeds in line with strong target affinity. CONCLUSION The present work covers a series of novel herbicidal lead structures that contain a spirocyclic lactam as a structural key feature carrying ortho-substituted benzyl or heteroarylmethylene side chains. These new compounds show good acyl-ACP thioesterase inhibition in line with strong herbicidal activity. Glasshouse trials showed that the spirolactams outlined herein display promising control of grass-weed species in pre-emergence application combined with dose-response windows that enable partial selectivity in wheat and corn. Remarkably, some of the novel acyl-ACP thioesterase-inhibitors showed efficacy against resistant grass weeds such as Alopecurus myosuroides and Lolium spp. on competitive levels compared with commercial standards. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Elisabeth Asmus
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - David M Barber
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Guido Bojack
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Birgit Bollenbach-Wahl
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Ronald W Brown
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Uwe Döller
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Jörg Freigang
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Elmar Gatzweiler
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Rahel Getachew
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Ines Heinemann
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Sabine Hohmann
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Kwang-Yoon Ko
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Bernd Laber
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Gudrun Lange
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Rebecca L Mattison
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Klemens Minn
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Thomas Müller
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Thomas Petry
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Anna M Reingruber
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Dirk Schmutzler
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Andrea Svejda
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
| | - Jens Frackenpohl
- Research & Development, Weed Control, Division Crop Science, Bayer AG, Industriepark Höchst, Frankfurt, Germany
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5
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Dhembla C, Kumar A, Arya R, Kundu S, Sundd M. Mitochondrial Acyl Carrier Protein of Leishmania major Displays Features Distinct from the Canonical Type II ACP. Biochemistry 2023; 62:3347-3359. [PMID: 37967383 DOI: 10.1021/acs.biochem.3c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
Prokaryotes synthesize fatty acids using a type II synthesis pathway (FAS). In this process, the central player, i.e., the acyl carrier protein (ACP), sequesters the growing acyl chain in its internal hydrophobic cavity. As the acyl chain length increases, the cavity expands in size, which is reflected in the NMR chemical shift perturbations and crystal structures of the acyl-ACP intermediates. A few eukaryotic organelles, such as plastids and mitochondria, also harbor type II fatty acid synthesis machinery. Plastid FAS from spinach and Plasmodium falciparum has been characterized at the molecular level, but the mitochondrial pathway remains unexplored. Here, we report NMR studies of the mitochondrial acyl-acyl carrier protein intermediates of Leishmania major (acyl-LmACP). Our studies show that LmACP experiences remarkably small conformational changes upon acylation, with perturbations confined to helices II and III only. CastP determined that the cavity size of apo-LmACP (PDB entry 5ZWT) is less than that of Escherichia coli ACP (PDB 1T8K). Thus, the small chemical shift perturbations observed in the LmACP intermediates, coupled with CastP results, suggest an unusually small cavity when fully expanded. The faster rate of C8-LmACP chain hydrolysis compared to E. coli ACP (EcACP) also supports these convictions. Structure comparison of LmACP with other type II ACP disclosed unique differences in the helix I and loop I conformations, as well as several residues present there. Numerous hydrophobic residues in helix I and loop I (conserved in all mitochondrial ACPs) are substituted with hydrophilic residues in the bacterial/plastid type II ACP. For instance, Phe and leucine at positions 14 and 34 in LmACP are substituted with a hydrophilic residue and Ala in bacterial/plastid type II ACP. Mutation of Leu 34 to Ala (corresponding residue in EcACP) resulted in a complete loss of structure, underscoring its importance in maintaining the ACP fold. Thus, our NMR studies, combined with insights from the crystal structure, highlight several unique features of LmACP, distinct from the prokaryote and plastid type II ACP. Given the high sequence identity, the features might be conserved in all mitochondrial ACPs.
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Affiliation(s)
- Chetna Dhembla
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Ambrish Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| | - Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
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6
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Abel SAG, Alnafta N, Asmus E, Bollenbach-Wahl B, Braun R, Dittgen J, Endler A, Frackenpohl J, Freigang J, Gatzweiler E, Heinemann I, Helmke H, Laber B, Lange G, Machettira A, McArthur G, Müller T, Odaybat M, Reingruber AM, Roth S, Rosinger CH, Schmutzler D, Schulte W, Stoppel R, Tiebes J, Volpin G, Barber DM. A Study in Scaffold Hopping: Discovery and Optimization of Thiazolopyridines as Potent Herbicides That Inhibit Acyl-ACP Thioesterase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:18212-18226. [PMID: 37677080 DOI: 10.1021/acs.jafc.3c02490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
In the search for new chemical entities that can control resistant weeds by addressing novel modes of action (MoAs), we were interested in further exploring a compound class that contained a 1,8-naphthyridine core. By leveraging scaffold hopping methodologies, we were able to discover the new thiazolopyridine compound class that act as potent herbicidal molecules. Further biochemical investigations allowed us to identify that the thiazolopyridines inhibit acyl-acyl carrier protein (ACP) thioesterase (FAT), with this being further confirmed via an X-ray cocrystal structure. Greenhouse trials revealed that the thiazolopyridines display excellent control of grass weed species in pre-emergence application coupled with dose response windows that enable partial selectivity in certain crops.
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Affiliation(s)
- Steven A G Abel
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Neanne Alnafta
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Elisabeth Asmus
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Birgit Bollenbach-Wahl
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Ralf Braun
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Jan Dittgen
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Anne Endler
- Targenomix GmbH, Am Mühlenberg 11, 14476, Potsdam, Germany
| | - Jens Frackenpohl
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Jörg Freigang
- Research and Development, Hit Discovery, Bayer AG, Crop Science Division, Alfred-Nobel-Straße 50, 40789, Monheim am Rhein, Germany
| | - Elmar Gatzweiler
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Ines Heinemann
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Hendrik Helmke
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Bernd Laber
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Gudrun Lange
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Anu Machettira
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Gillian McArthur
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Thomas Müller
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Magdalena Odaybat
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Anna M Reingruber
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Sina Roth
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Christopher H Rosinger
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Dirk Schmutzler
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Wolfgang Schulte
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Rhea Stoppel
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Jörg Tiebes
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Giulio Volpin
- Research and Development, Small Molecules Technologies, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - David M Barber
- Research and Development, Weed Control Research, Bayer AG, Crop Science Division, Industriepark Höchst, 65926, Frankfurt am Main, Germany
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7
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Cai Z, Xian P, Cheng Y, Yang Y, Zhang Y, He Z, Xiong C, Guo Z, Chen Z, Jiang H, Ma Q, Nian H, Ge L. Natural variation of GmFATA1B regulates seed oil content and composition in soybean. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:2368-2379. [PMID: 37655952 DOI: 10.1111/jipb.13561] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/30/2023] [Indexed: 09/02/2023]
Abstract
Soybean (Glycine max) produces seeds that are rich in unsaturated fatty acids and is an important oilseed crop worldwide. Seed oil content and composition largely determine the economic value of soybean. Due to natural genetic variation, seed oil content varies substantially across soybean cultivars. Although much progress has been made in elucidating the genetic trajectory underlying fatty acid metabolism and oil biosynthesis in plants, the causal genes for many quantitative trait loci (QTLs) regulating seed oil content in soybean remain to be revealed. In this study, we identified GmFATA1B as the gene underlying a QTL that regulates seed oil content and composition, as well as seed size in soybean. Nine extra amino acids in the conserved region of GmFATA1B impair its function as a fatty acyl-acyl carrier protein thioesterase, thereby affecting seed oil content and composition. Heterogeneously overexpressing the functional GmFATA1B allele in Arabidopsis thaliana increased both the total oil content and the oleic acid and linoleic acid contents of seeds. Our findings uncover a previously unknown locus underlying variation in seed oil content in soybean and lay the foundation for improving seed oil content and composition in soybean.
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Affiliation(s)
- Zhandong Cai
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Shaoguan University, Shaoguan, 512000, China
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China
| | - Peiqi Xian
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Yanbo Cheng
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Yuan Yang
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Yakun Zhang
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Zihang He
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Chuwen Xiong
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Zhibin Guo
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Zhicheng Chen
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Huiqian Jiang
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Qibin Ma
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
| | - Hai Nian
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Liangfa Ge
- Guangdong Sub-center of National Center for Soybean Improvement, South China Agricultural University, Guangzhou, 510642, China
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China
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8
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Li X, Yang M, Sun D, Shi J, Yang M, Feng Y, Xue S. Unique recognition of the microalgal plastidial glycerol-3-phosphate acyltransferase for acyl-ACP. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 332:111725. [PMID: 37142097 DOI: 10.1016/j.plantsci.2023.111725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/06/2023]
Abstract
Plastidial glycerol-3-phosphate acyltransferases (GPATs) catalyze acyl-ACP and glycerol-3-phosphate to synthesize lysophosphatidic acid in vivo, which initiates the formation of various glycerolipids. Although the physiological substrates of plastidial GPATs are acyl-ACPs, acyl-CoAs have been commonly studied on the GPATs in vitro. However, little is known whether there are any distinct features of GPATs towards acyl-ACP and acyl-CoA. In this study, the results showed that the microalgal plastidial GPATs preferred acyl-ACP to acyl-CoA, while surprisingly, the plant-derived plastidial GPATs showed no obvious preferences towards these two acyl carriers. The key residues responsible for the distinct feature of microalgal plastidial GPATs were compared with plant-derived plastidial GPATs in their efficiency to catalyze acyl-ACP and acyl-CoA. Microalgal plastidial GPATs uniquely recognized acyl-ACP as compared to with other acyltransferases. The structure of the acyltransferases-ACP complex highlights only the involvement of the large structural domain in ACP in microalgal plastidial GPAT while in the other acyltransferases, both large and small structural domains were involved in the recognition process. The interaction sites on the plastidial GPAT from the green alga Myrmecia incisa (MiGPAT1) with ACP turned out to be K204, R212 and R266. A unique recognition between the microalgal plastidial GPAT and ACP was elucidated.
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Affiliation(s)
- Xianglong Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Miao Yang
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, 116081, China
| | - Dongru Sun
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Jianping Shi
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Ming Yang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yanbin Feng
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
| | - Song Xue
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
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9
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Çolak NG, Eken NT, Ülger M, Frary A, Doğanlar S. Mapping of quantitative trait loci for the nutritional value of fresh market tomato. Funct Integr Genomics 2023; 23:121. [PMID: 37039853 DOI: 10.1007/s10142-023-01045-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/12/2023]
Abstract
The incidence of many diseases, such as cancer, cardiovascular diseases, and diabetes, is associated with malnutrition and an unbalanced daily diet. Vegetables are an important source of vitamins and essential compounds for human health. As a result, such metabolites have increasingly become the focus of breeding programs. Tomato is one of the most popular components of our daily diet. Therefore, the improvement of tomato's nutritional quality is an important goal. In the present study, we performed targeted metabolic profiling of an interspecific Solanum pimpinellifolium × S. lycopersicum inbred backcross line (IBL) population and identified quantitative trait loci responsible for the nutritional value of tomato. Transgressive segregation was apparent for many of the nutritional compounds such that some IBLs had extremely high levels of various amino acids and vitamins compared to their parents. A total of 117 QTLs for nutritional traits including 62 QTLs for amino acids, 18 QTLs for fatty acids, 12 QTLs for water-soluble vitamins, and 25 QTLs for fat-soluble vitamins were identified. Moreover, almost 24% of identified QTLs were confirmed in previous studies, and 40 possible gene candidates were found for 18 identified QTLs. These findings can help breeders to improve the nutritional value of tomato.
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Affiliation(s)
- Nergiz Gürbüz Çolak
- Department of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, İzmir, 35430, Turkey
- Plant Science and Technology Application and Research Center, Izmir Institute of Technology, İzmir, 35430, Turkey
| | - Neslihan Tek Eken
- Department of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, İzmir, 35430, Turkey
| | - Mehmet Ülger
- MULTI Tarım Seed Company, Antalya, 07112, Turkey
| | - Anne Frary
- Department of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, İzmir, 35430, Turkey
| | - Sami Doğanlar
- Department of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, İzmir, 35430, Turkey.
- Plant Science and Technology Application and Research Center, Izmir Institute of Technology, İzmir, 35430, Turkey.
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10
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Yang T, Yang Y, Yang M, Ren J, Xue C, Feng Y, Xue S. Conformational Changes of Acyl Carrier Protein Switch the Chain Length Preference of Acyl-ACP Thioesterase ChFatB2. Int J Mol Sci 2023; 24:ijms24076864. [PMID: 37047837 PMCID: PMC10095102 DOI: 10.3390/ijms24076864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 04/09/2023] Open
Abstract
Microbial fatty acids are synthesized by Type II fatty acid synthase and could be tailored by acyl-ACP thioesterase. With the prospects of medium-chain fatty-acid-derivative biofuels, the selectivity of thioesterase has been studied to control the fatty acid product chain length. Here, we report an alternative approach by manipulating the acyl carrier protein portion of acyl-ACP to switch the chain length propensity of the thioesterase. It was demonstrated that ChFatB2 from Cuphea hookeriana preferred C10-ACP to C8-ACP with ACP from E. coli, while converting preference to C8-ACP with ACP from Cuphea lanceolate. Circular dichroism (CD) results indicated that the C8-EcACP encountered a 34.4% α-helix increment compared to C10-EcACP, which resulted in an approximate binding affinity decrease in ChFatB2 compared to C10-EcACP. Similarly, the C10-ClACP2 suffered a 45% decrease in helix content compared to C8–ClACP2, and the conformational changes resulted in an 18% binding affinity decline with ChFatB2 compared with C10-ClACP2. In brief, the study demonstrates that the ACP portion of acyl-ACP contributes to the selectivity of acyl-ACP thioesterase, and the conformational changes of EcACP and ClACP2 switch the chain length preference of ChFatB2 between C8 and C10. The result provides fundamentals for the directed synthesis of medium-chain fatty acids based on regulating the conformational changes of ACPs.
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Affiliation(s)
- Tianxiang Yang
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Yunlong Yang
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Ming Yang
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Jiangang Ren
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Changying Xue
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Yanbin Feng
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
| | - Song Xue
- School of Bioengineering, Dalian University of Technology, Dalian 116023, China
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11
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Evaluation of strategies to narrow the product chain-length distribution of microbially synthesized free fatty acids. Metab Eng 2023; 77:21-31. [PMID: 36863604 DOI: 10.1016/j.ymben.2023.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/29/2023] [Accepted: 02/28/2023] [Indexed: 03/04/2023]
Abstract
The dominant strategy for tailoring the chain-length distribution of free fatty acids (FFA) synthesized by heterologous hosts is expression of a selective acyl-acyl carrier protein (ACP) thioesterase. However, few of these enzymes can generate a precise (greater than 90% of a desired chain-length) product distribution when expressed in a microbial or plant host. The presence of alternative chain-lengths can complicate purification in situations where blends of fatty acids are not desired. We report the assessment of several strategies for improving the dodecanoyl-ACP thioesterase from the California bay laurel to exhibit more selective production of medium-chain free fatty acids to near exclusivity. We demonstrated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) was an effective library screening technique for identification of thioesterase variants with favorable shifts in chain-length specificity. This strategy proved to be a more effective screening technique than several rational approaches discussed herein. With this data, we isolated four thioesterase variants which exhibited a more selective FFA distribution over wildtype when expressed in the fatty acid accumulating E. coli strain, RL08. We then combined mutations from the MALDI isolates to generate BTE-MMD19, a thioesterase variant capable of producing free fatty acids consisting of 90% of C12 products. Of the four mutations which conferred a specificity shift, we noted that three affected the shape of the binding pocket, while one occurred on the positively charged acyl carrier protein landing pad. Finally, we fused the maltose binding protein (MBP) from E. coli to the N - terminus of BTE-MMD19 to improve enzyme solubility and achieve a titer of 1.9 g per L of twelve-carbon fatty acids in a shake flask.
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12
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Strategies to Enhance the Biosynthesis of Monounsaturated Fatty Acids in Escherichia coli. BIOTECHNOL BIOPROC E 2023. [DOI: 10.1007/s12257-022-0295-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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13
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Kalinger RS, Rowland O. Determinants of substrate specificity in a catalytically diverse family of acyl-ACP thioesterases from plants. BMC PLANT BIOLOGY 2023; 23:1. [PMID: 36588156 PMCID: PMC9806908 DOI: 10.1186/s12870-022-04003-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 12/13/2022] [Indexed: 05/05/2023]
Abstract
BACKGROUND ACYL-LIPID THIOESTERASES (ALTs) are a subclass of plastid-localized, fatty acyl-acyl carrier protein (ACP) thioesterase enzymes from plants. They belong to the single hot dog-fold protein family. ALT enzymes generate medium-chain (C6-C14) and C16 fatty acids, methylketone precursors (β-keto fatty acids), and 3-hydroxy fatty acids when expressed heterologously in E. coli. The diverse substrate chain-length and oxidation state preferences of ALTs set them apart from other plant acyl-ACP thioesterases, and ALTs show promise as metabolic engineering tools to produce high-value medium-chain fatty acids and methylketones in bacterial or plant systems. Here, we used a targeted motif-swapping approach to explore connections between ALT protein sequence and substrate specificity. Guided by comparative motif searches and computational modelling, we exchanged regions of amino acid sequence between ALT-type thioesterases from Arabidopsis thaliana, Medicago truncatula, and Zea mays to create chimeric ALT proteins. RESULTS Comparing the activity profiles of chimeric ALTs in E. coli to their wild-type counterparts led to the identification of interacting regions within the thioesterase domain that shape substrate specificity and enzyme activity. Notably, the presence of a 31-CQH[G/C]RH-36 motif on the central α-helix was shown to shift chain-length specificity towards 12-14 carbon chains, and to be a core determinant of substrate specificity in ALT-type thioesterases with preference for 12-14 carbon 3-hydroxyacyl- and β-ketoacyl-ACP substrates. For an ALT containing this motif to be functional, an additional 108-KXXA-111 motif and compatible sequence spanning aa77-93 of the surrounding β-sheet must also be present, demonstrating that interactions between residues in these regions of the catalytic domain are critical to thioesterase activity. The behaviour of chimeric enzymes in E. coli also indicated that aa77-93 play a significant role in dictating whether an ALT will prefer ≤10-carbon or ≥ 12-carbon acyl chain-lengths, and aa91-96 influence selectivity for substrates of fully or partially reduced oxidation states. Additionally, aa64-67 on the hot dog-fold β-sheet were shown to be important for enabling an ALT to act on 3-hydroxy fatty acyl-ACP substrates. CONCLUSIONS By revealing connections between thioesterase sequence and substrate specificity, this study is an advancement towards engineering recombinant ALTs with product profiles suited for specific applications.
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Affiliation(s)
- Rebecca S Kalinger
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Owen Rowland
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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14
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Pu Y, Cao Y, Xian M. Modification of Fatty Acid Composition of Escherichia coli by Co-Expression of Fatty Acid Desaturase and Thioesterase from Arabidopsis thaliana. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9120771. [PMID: 36550977 PMCID: PMC9774610 DOI: 10.3390/bioengineering9120771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/22/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
Fatty acid composition has an important influence on the fluidity of biological membranes, which is a key factor for the survival of Escherichia coli. With the aim to modify fatty acid composition in this experimentally friendly microorganism, the AtFab2 gene, encoding the Arabidopsis thaliana fatty acid desaturase, was expressed separately and jointly with AtFatA, a fatty acid thioesterase of the same plant origin. The expression of ATFab2 desaturase resulted in an enhancement of cis-vaccenic acid (18:1Δ11) contents, while amounts of palmitioleic acid (16:1Δ9) accumulated by E. coli were increased by 130% for the expression of the AtFatA thioesterase. In the final engineered strain co-expressing AtFab2 and AtFatA, the percentage of palmitic acid (16:0), the most abundant saturated fatty acid found in E. coli, was reduced to 29.9% and the ratio of unsaturated fatty acid to saturated fatty acid reached 2:1. Free fatty acids accounted for about 40% of total fatty acid profiles in the recombinant strain expressing both two genes, and the unsaturated fatty acid contents reached nearly 75% in the free fatty acid profiles. The increase of unsaturated fatty acid level might provide some implication for the construction of cold tolerant strains.
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Affiliation(s)
- Yihan Pu
- The High School Affiliated to Renmin University of China, Beijing 100086, China
| | - Yujin Cao
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Correspondence: (Y.C.); (M.X.)
| | - Mo Xian
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Correspondence: (Y.C.); (M.X.)
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15
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Chen M, Yang C, Deng L, Wang F, Liu J. Production of 1, 3- medium chain-2-long chain (MLM) triacylglycerols by metabolically engineered Escherichia coli. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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16
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Caswell BT, de Carvalho CC, Nguyen H, Roy M, Nguyen T, Cantu DC. Thioesterase enzyme families: Functions, structures, and mechanisms. Protein Sci 2022; 31:652-676. [PMID: 34921469 PMCID: PMC8862431 DOI: 10.1002/pro.4263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Thioesterases are enzymes that hydrolyze thioester bonds in numerous biochemical pathways, for example in fatty acid synthesis. This work reports known functions, structures, and mechanisms of updated thioesterase enzyme families, which are classified into 35 families based on sequence similarity. Each thioesterase family is based on at least one experimentally characterized enzyme, and most families have enzymes that have been crystallized and their tertiary structure resolved. Classifying thioesterases into families allows to predict tertiary structures and infer catalytic residues and mechanisms of all sequences in a family, which is particularly useful because the majority of known protein sequence have no experimental characterization. Phylogenetic analysis of experimentally characterized thioesterases that have structures with the two main structural folds reveal convergent and divergent evolution. Based on tertiary structure superimposition, catalytic residues are predicted.
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Affiliation(s)
- Benjamin T. Caswell
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Caio C. de Carvalho
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Hung Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Monikrishna Roy
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Tin Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - David C. Cantu
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
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17
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Otyama PI, Chamberlin K, Ozias-Akins P, Graham MA, Cannon EKS, Cannon SB, MacDonald GE, Anglin NL. Genome-wide approaches delineate the additive, epistatic, and pleiotropic nature of variants controlling fatty acid composition in peanut (Arachis hypogaea L.). G3-GENES GENOMES GENETICS 2021; 12:6423989. [PMID: 34751378 DOI: 10.1093/g3journal/jkab382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/26/2021] [Indexed: 11/12/2022]
Abstract
The fatty acid composition of seed oil is a major determinant of the flavor, shelf-life, and nutritional quality of peanuts. Major QTLs controlling high oil content, high oleic content, and low linoleic content have been characterized in several seed oil crop species. Here we employ genome-wide association approaches on a recently genotyped collection of 787 plant introduction accessions in the USDA peanut core collection, plus selected improved cultivars, to discover markers associated with the natural variation in fatty acid composition, and to explain the genetic control of fatty acid composition in seed oils. Overall, 251 single nucleotide polymorphisms (SNPs) had significant trait associations with the measured fatty acid components. Twelve SNPs were associated with two or three different traits. Of these loci with apparent pleiotropic effects, 10 were associated with both oleic (C18:1) and linoleic acid (C18:2) content at different positions in the genome. In all 10 cases, the favorable allele had an opposite effect-increasing and lowering the concentration, respectively, of oleic and linoleic acid. The other traits with pleiotropic variant control were palmitic (C16:0), behenic (C22:0), lignoceric (C24:0), gadoleic (C20:1), total saturated, and total unsaturated fatty acid content. One hundred (100) of the significantly associated SNPs were located within 1000 kbp of 55 genes with fatty acid biosynthesis functional annotations. These genes encoded, among others: ACCase carboxyl transferase subunits, and several fatty acid synthase II enzymes. With the exception of gadoleic (C20:1) and lignoceric (C24:0) acid content, which occur at relatively low abundance in cultivated peanut, all traits had significant SNP interactions exceeding a stringent Bonferroni threshold (α = 1%). We detected 7,682 pairwise SNP interactions affecting the relative abundance of fatty acid components in the seed oil. Of these, 627 SNP pairs had at least one SNP within 1000 kbp of a gene with fatty acid biosynthesis functional annotation. We evaluated 168 candidate genes underlying these SNP interactions. Functional enrichment and protein-to-protein interactions supported significant interactions (p-value < 1.0E-16) among the genes evaluated. These results show the complex nature of the biology and genes underlying the variation in seed oil fatty acid composition and contribute to an improved genotype-to-phenotype map for fatty acid variation in peanut seed oil.
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Affiliation(s)
- Paul I Otyama
- Interdepartmental Genetics and Genomics, Iowa State University, Ames, IA 50011, USA.,Agronomy Department, Iowa State University, Ames, IA 50011, USA.,ORISE Postdoctoral Fellow, Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA 50011, USA
| | - Kelly Chamberlin
- USDA-Agricultural Research Service, Stillwater, OK 740752714, USA
| | - Peggy Ozias-Akins
- Institute of Plant Breeding, Genetics, and Genomics and Department of Horticulture, University of Georgia, Tifton, GA 31793-5766, USA
| | - Michelle A Graham
- USDA-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - Ethalinda K S Cannon
- USDA-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - Steven B Cannon
- USDA-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | | | - Noelle L Anglin
- USDA-ARS Small Grains and Potato Research Laboratory, Aberdeen, ID 83210, USA
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18
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Kalinger RS, Williams D, Ahmadi Pirshahid A, Pulsifer IP, Rowland O. Production of C6-C14 Medium-Chain Fatty Acids in Seeds and Leaves via Overexpression of Single Hotdog-Fold Acyl-Lipid Thioesterases. Lipids 2021; 56:327-344. [PMID: 33547664 DOI: 10.1002/lipd.12299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/29/2020] [Accepted: 01/14/2021] [Indexed: 11/07/2022]
Abstract
ACYL-LIPID THIOESTERASES (ALT) are a type of plant acyl-acyl carrier protein thioesterase that generate a wide range of medium-chain fatty acids and methylketone (MK) precursors when expressed heterologously in Escherichia coli. While this makes ALT-type thioesterases attractive as metabolic engineering targets to increase production of high-value medium-chain fatty acids and MKs in plant systems, the behavior of ALT enzymes in planta was not well understood before this study. To profile the substrate specificities of ALT-type thioesterases in different plant tissue types, AtALT1-4 from Arabidopsis thaliana, which have widely varied chain length and oxidation state preferences in E. coli, were overexpressed in Arabidopsis seeds, Camelina sativa seeds, and Nicotiana benthamiana leaves. Seed-specific overexpression of ALT enzymes led to medium-chain fatty acid accumulation in Arabidopsis and Camelina seed triacylglycerols, and transient overexpression in N. benthamiana demonstrated that the substrate preferences of ALT-type thioesterases in planta generally agree with those previously determined in E. coli. AtALT1 and AtALT4 overexpression in leaves and seeds resulted in the accumulation of 12-14 carbon-length fatty acids and 6-8 carbon-length fatty acids, respectively. While it was difficult to completely profile the products of ALT-type thioesterases that generate MK precursors (i.e. β-keto fatty acids), our results nonetheless demonstrate that ALT enzymes are catalytically diverse in planta. The knowledge gained from this study is a significant step towards being able to use ALT-type thioesterases as metabolic engineering tools to modify the fatty acid profiles of oilseed crops, other plants, and microorganisms.
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Affiliation(s)
- Rebecca S Kalinger
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Danielle Williams
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Ali Ahmadi Pirshahid
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Ian P Pulsifer
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Owen Rowland
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
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19
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Wang Q, Feng Y, Lu Y, Xin Y, Shen C, Wei L, Liu Y, Lv N, Du X, Zhu W, Jeong BR, Xue S, Xu J. Manipulating fatty-acid profile at unit chain-length resolution in the model industrial oleaginous microalgae Nannochloropsis. Metab Eng 2021; 66:157-166. [PMID: 33823272 DOI: 10.1016/j.ymben.2021.03.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/22/2021] [Accepted: 03/28/2021] [Indexed: 12/01/2022]
Abstract
The chain length (CL) of fatty acids (FAs) is pivotal to oil property, yet to what extent it can be customized in industrial oleaginous microalgae is unknown. In Nannochloropsis oceanica, to modulate long-chain FAs (LCFAs), we first discovered a fungi/bacteria-originated polyketide synthase (PKS) system which involves a cytoplasmic acyl-ACP thioesterase (NoTE1). NoTE1 hydrolyzes C16:0-, C16:1- and C18:1-ACP in vitro and thus intercepts the specific acyl-ACPs elongated by PKS for polyunsaturated FA biosynthesis, resulting in elevation of C16/C18 monounsaturated FAs when overproduced and increase of C20 when knocked out. For medium-chain FAs (MCFAs; C8-C14), C8:0 and C10:0 FAs are boosted by introducing a Cuphea palustris acyl-ACP TE (CpTE), whereas C12:0 elevated by rationally engineering CpTE enzyme's substrate-binding pocket to shift its CL preference towards C12:0. A mechanistic model exploiting both native and engineered PKS and type II FAS pathways was thus proposed for manipulation of carbon distribution among FAs of various CL. The ability to tailor FA profile at the unit CL resolution from C8 to C20 in Nannochloropsis spp. lays the foundation for scalable production of designer lipids via industrial oleaginous microalgae.
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Affiliation(s)
- Qintao Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yanbin Feng
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yandu Lu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chen Shen
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yuxue Liu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China; University of Chinese Academy of Sciences, Beijing, China
| | - Nana Lv
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xuefeng Du
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Wenqiang Zhu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Byeong-Ryool Jeong
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Song Xue
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Laboratory of Energy Genetics and Shandong Energy Institute, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China; University of Chinese Academy of Sciences, Beijing, China.
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20
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Liu Y, Guo X, Liu W, Wang J, Kent Zhao Z. Structural Insights into Malic Enzyme Variants Favoring an Unnatural Redox Cofactor. Chembiochem 2021; 22:1765-1768. [PMID: 33523590 DOI: 10.1002/cbic.202000800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/27/2021] [Indexed: 01/07/2023]
Abstract
The use of nicotinamide cytosine dinucleotide (NCD), a biocompatible nicotinamide adenosine dinucleotide (NAD) analogue, is of great scientific and biotechnological interest. Several redox enzymes have been devised to favor NCD, and have been successfully applied in creating NCD-dependent redox systems. However, molecular interactions between cofactor and protein have still to be disclosed in order to guide further engineering efforts. Here we report the structural analysis of an NCD-favoring malic enzyme (ME) variant derived from Escherichia coli. The X-ray crystal structure data revealed that the residues located at position 346 and 401 in ME acted as the "gatekeepers" of the adenine moiety binding cavity. When Arg346 was substituted with either acidic or aromatic residues, the corresponding mutants showed substantially reduced NCD preference. Inspired by these observations, we generated Lactobacillus helveticus derived d-lactate dehydrogenase variants at Ile177, the counterpart to Arg346 in ME, and found a similar trend in terms of cofactor preference changes. As many NAD-dependent oxidoreductases share key structural features, our results provide guidance for protein engineering to obtain more NCD-favoring variants.
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Affiliation(s)
- Yuxue Liu
- College of Life Sciences, Henan Normal University, 46 East of Construction Road, Xinxiang, 453007, P. R. China.,Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China
| | - Xiaojia Guo
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China
| | - Wujun Liu
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.,Present address: Institute of Cancer Stem Cell, Dalian Medical University, Dalian, 116044, P. R. China
| | - Junting Wang
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China
| | - Zongbao Kent Zhao
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.,State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, Dalian, 116023, P. R. China
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21
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Martins-Noguerol R, DeAndrés-Gil C, Garcés R, Salas J, Martínez-Force E, Moreno-Pérez A. Characterization of the acyl-ACP thioesterases from Koelreuteria paniculata reveals a new type of FatB thioesterase. Heliyon 2020; 6:e05237. [PMID: 33102858 PMCID: PMC7569226 DOI: 10.1016/j.heliyon.2020.e05237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/03/2020] [Accepted: 10/08/2020] [Indexed: 11/04/2022] Open
Abstract
Koelreuteria paniculata is a deciduous tree, popular in temperate regions for its ornamental value, which accumulates unusual cyanolipids in its seeds. The seed oil of this plant is rich in the unusual cis-11-eicosenoic fatty acid (20:1, or gondoic acid), a monounsaturated oil of interest to the oleochemical industry. In higher plants, de novo fatty acid biosynthesis takes place in the plastids, a process that is terminated by hydrolysis of the thioester bond between the acyl moiety and the ACP by acyl-ACP thioesterases. The specificity of acyl-ACP thioesterases is fundamental in controlling the fatty acid composition of seed oil. To determine the mechanisms involved in fatty acid biosynthesis in K. paniculata seeds, we isolated, cloned and sequenced two cDNAs encoding acyl-ACP thioesterases in this plant, KpFatA and KpFatB. Both of them were expressed heterologously in Escherichia coli and characterized with different acyl-ACP substrates. The K. paniculata FatB2 displayed unusual substrate specificity, so that unlike most FatB2 type enzymes, it displayed preference for oleoyl-ACP instead of palmitoyl-ACP. This specificity was consistent with the changes in E. coli and N. benthamiana fatty acid composition following heterologous expression of this enzyme. KpFatB also showed certain genetic divergence relative to other FatB-type thioesterases and when modelled, its structure revealed differences at the active site. Together, these results suggest that this thioesterase could be a new class of FatB not described previously.
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Affiliation(s)
- R. Martins-Noguerol
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
| | - C. DeAndrés-Gil
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
| | - R. Garcés
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
| | - J.J. Salas
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
| | - E. Martínez-Force
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
| | - A.J. Moreno-Pérez
- Group of Genetics and Biochemistry of Seed Lipids, Department of Biochemistry and Molecular Biology of Plants Products, Instituto de la Grasa (CSIC), Ctra. de Utrera km 1, Building 46, 41013 Sevilla, Spain
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22
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Cho IJ, Choi KR, Lee SY. Microbial production of fatty acids and derivative chemicals. Curr Opin Biotechnol 2020; 65:129-141. [DOI: 10.1016/j.copbio.2020.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 12/11/2022]
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23
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Swarbrick CMD, Nanson JD, Patterson EI, Forwood JK. Structure, function, and regulation of thioesterases. Prog Lipid Res 2020; 79:101036. [PMID: 32416211 DOI: 10.1016/j.plipres.2020.101036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/15/2023]
Abstract
Thioesterases are present in all living cells and perform a wide range of important biological functions by catalysing the cleavage of thioester bonds present in a diverse array of cellular substrates. Thioesterases are organised into 25 families based on their sequence conservation, tertiary and quaternary structure, active site configuration, and substrate specificity. Recent structural and functional characterisation of thioesterases has led to significant changes in our understanding of the regulatory mechanisms that govern enzyme activity and their respective cellular roles. The resulting dogma changes in thioesterase regulation include mechanistic insights into ATP and GDP-mediated regulation by oligomerisation, the role of new key regulatory regions, and new insights into a conserved quaternary structure within TE4 family members. Here we provide a current and comparative snapshot of our understanding of thioesterase structure, function, and regulation across the different thioesterase families.
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Affiliation(s)
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Edward I Patterson
- Centre for Neglected Tropical Diseases, Departments of Vector Biology and Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, New South Wales, Australia.
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24
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Deng X, Chen L, Hei M, Liu T, Feng Y, Yang GY. Structure-guided reshaping of the acyl binding pocket of 'TesA thioesterase enhances octanoic acid production in E. coli. Metab Eng 2020; 61:24-32. [PMID: 32339761 DOI: 10.1016/j.ymben.2020.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/23/2020] [Accepted: 04/16/2020] [Indexed: 12/21/2022]
Abstract
Medium-chain fatty acids (C6-C10) have attracted much attention recently for their unique properties compared to their long-chain counterparts, including low melting points and relatively higher carbon conversion yield. Thioesterase enzymes, which can catalyze the hydrolysis of acyl-ACP (acyl carrier protein) to release free fatty acids (FAs), regulate both overall FA yields and acyl chain length distributions in bacterial and yeast fermentation cultures. These enzymes typically prefer longer chain substrates. Herein, seeking to increase bacterial production of MCFAs, we conducted structure-guided mutational screening of multiple residues in the substrate-binding pocket of the E. coli thioesterase enzyme 'TesA. Confirming our hypothesis that enhancing substrate selectivity for medium-chain acyl substrates would promote overall MCFA production, we found that replacement of residues lining the bottom of the pocket with more hydrophobic residues strongly promoted the C8 substrate selectivity of 'TesA. Specifically, two rounds of saturation mutagenesis led to the identification of the 'TesARD-2 variant that exhibited a 133-fold increase in selectivity for the C8-ACP substrate as compared to C16-ACP substrate. Moreover, the recombinant expression of this variant in an E. coli strain with a blocked β-oxidation pathway led to a 1030% increase in the in vivo octanoic acid (C8) production titer. When this strain was fermented in a 5-L fed-batch bioreactor, it produced 2.7 g/L of free C8 (45%, molar fraction) and 7.9 g/L of total free FAs, which is the highest-to-date free C8 titer to date reported using the E. coli type II fatty acid synthetic pathway. Thus, reshaping the substrate binding pocket of a bacterial thioesterase enzyme by manipulating the hydrophobicity of multiple residues altered the substrate selectivity and therefore fatty acid product distributions in cells. Our study demonstrates the relevance of this strategy for increasing titers of industrially attractive MCFAs as fermentation products.
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Affiliation(s)
- Xi Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liuqing Chen
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mohan Hei
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tiangang Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430072, China
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Guang-Yu Yang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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25
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Kalinger RS, Pulsifer IP, Hepworth SR, Rowland O. Fatty Acyl Synthetases and Thioesterases in Plant Lipid Metabolism: Diverse Functions and Biotechnological Applications. Lipids 2020; 55:435-455. [PMID: 32074392 DOI: 10.1002/lipd.12226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 11/09/2022]
Abstract
Plants use fatty acids to synthesize acyl lipids for many different cellular, physiological, and defensive roles. These roles include the synthesis of essential membrane, storage, or surface lipids, as well as the production of various fatty acid-derived metabolites used for signaling or defense. Fatty acids are activated for metabolic processing via a thioester linkage to either coenzyme A or acyl carrier protein. Acyl synthetases metabolically activate fatty acids to their thioester forms, and acyl thioesterases deactivate fatty acyl thioesters to free fatty acids by hydrolysis. These two enzyme classes therefore play critical roles in lipid metabolism. This review highlights the surprisingly complex and varying roles of fatty acyl synthetases in plant lipid metabolism, including roles in the intracellular trafficking of fatty acids. This review also surveys the many specialized fatty acyl thioesterases characterized to date in plants, which produce a great diversity of fatty acid products in a tissue-specific manner. While some acyl thioesterases produce fatty acids that clearly play roles in plant-insect or plant-microbial interactions, most plant acyl thioesterases have yet to be fully characterized both in terms of their substrate specificities and their functions. The biotechnological applications of plant acyl thioesterases and synthetases are also discussed, as there is significant interest in these enzymes as catalysts for the sustainable production of fatty acids and their derivatives for industrial uses.
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Affiliation(s)
- Rebecca S Kalinger
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Ian P Pulsifer
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Shelley R Hepworth
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Owen Rowland
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
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26
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Heil CS, Wehrheim SS, Paithankar KS, Grininger M. Fatty Acid Biosynthesis: Chain‐Length Regulation and Control. Chembiochem 2019; 20:2298-2321. [DOI: 10.1002/cbic.201800809] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/20/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Christina S. Heil
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - S. Sophia Wehrheim
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Karthik S. Paithankar
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
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27
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Feng Y, Zhang Y, Ding W, Wu P, Cao X, Xue S. Expanding of Phospholipid:Diacylglycerol AcylTransferase (PDAT) from Saccharomyces cerevisiae as Multifunctional Biocatalyst with Broad Acyl Donor/Acceptor Selectivity. Appl Biochem Biotechnol 2019; 188:824-835. [PMID: 30706417 DOI: 10.1007/s12010-019-02954-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/11/2019] [Indexed: 12/27/2022]
Abstract
Triacylglycerols are considered one of the most promising feedstocks for biofuels. Phospholipid:diacylglycerol acyltransferase (PDAT), responsible for the last step of triacylglycerol synthesis in the acyl-CoA-independent pathway, has attracted much attention by catalyzing membrane lipid transformation. However, due to lack of biochemical and enzymatic studies, PDAT has not carried forward in biocatalyst application. Here, the PDAT from Saccharomyces cerevisiae was expressed in Pichia pastoris. The purified enzymes were studied using different acyl donors and acceptors by thin layer chromatography and gas chromatography. In addition of the preferred acyl donor of PE and PC, the results identified that ScPDAT was capable of using broad acyl donors such as PA, PS, PG, MGDG, DGDG, and acyl-CoA, and ScPDAT was more likely to use unsaturated acyl donors comparing 18:0/18:1 to 18:0/18:0 phospholipids. With regard to acyl acceptors, ScPDAT preferred 1,2 to 1,3-diacylglycerol (DAG), while 12:0/12:0 DAG was identified as the optimal acyl acceptor, followed by 18:1/18:1 and 18:1/16:0 DAG. Additionally, ScPDAT reveals esterification activity that can utilize methanol as acyl acceptor to generate fatty acid methyl esters. The results fully expand the enzymatic selectivity of ScPDAT and provide fundamental knowledge for synthesis of triacylglycerol-derived biofuels.
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Affiliation(s)
- Yanbin Feng
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Yunxiu Zhang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Wei Ding
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Peichun Wu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Xupeng Cao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Song Xue
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
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28
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Identification of active site residues implies a two-step catalytic mechanism for acyl-ACP thioesterase. Biochem J 2018; 475:3861-3873. [DOI: 10.1042/bcj20180470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 02/02/2023]
Abstract
In plants and bacteria that use a Type II fatty acid synthase, isozymes of acyl-acyl carrier protein (ACP) thioesterase (TE) hydrolyze the thioester bond of acyl-ACPs, terminating the process of fatty acid biosynthesis. These TEs are therefore critical in determining the fatty acid profiles produced by these organisms. Past characterizations of a limited number of plant-sourced acyl-ACP TEs have suggested a thiol-based, papain-like catalytic mechanism, involving a triad of Cys, His, and Asn residues. In the present study, the sequence alignment of 1019 plant and bacterial acyl-ACP TEs revealed that the previously proposed Cys catalytic residue is not universally conserved and therefore may not be a catalytic residue. Systematic mutagenesis of this residue to either Ser or Ala in three plant acyl-ACP TEs, CvFatB1 and CvFatB2 from Cuphea viscosissima and CnFatB2 from Cocos nucifera, resulted in enzymatically active variants, demonstrating that this Cys residue (Cys348 in CvFatB2) is not catalytic. In contrast, the multiple sequence alignment, together with the structure modeling of CvFatB2, suggests that the highly conserved Asp309 and Glu347, in addition to previously proposed Asn311 and His313, may be involved in catalysis. The substantial loss of catalytic competence associated with site-directed mutants at these positions confirmed the involvement of these residues in catalysis. By comparing the structures of acyl-ACP TE and the Pseudomonas 4-hydroxybenzoyl-CoA TE, both of which fold in the same hotdog tertiary structure and catalyze the hydrolysis reaction of thioester bond, we have proposed a two-step catalytic mechanism for acyl-ACP TE that involves an enzyme-bound anhydride intermediate.
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29
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Aznar-Moreno JA, Sánchez R, Gidda SK, Martínez-Force E, Moreno-Pérez AJ, Venegas Calerón M, Garcés R, Mullen RT, Salas JJ. New Insights Into Sunflower ( Helianthus annuus L.) FatA and FatB Thioesterases, Their Regulation, Structure and Distribution. FRONTIERS IN PLANT SCIENCE 2018; 9:1496. [PMID: 30459777 PMCID: PMC6232763 DOI: 10.3389/fpls.2018.01496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/25/2018] [Indexed: 05/13/2023]
Abstract
Sunflower seeds (Helianthus annuus L.) accumulate large quantities of triacylglycerols (TAG) between 12 and 28 days after flowering (DAF). This is the period of maximal acyl-acyl carrier protein (acyl-ACP) thioesterase activity in vitro, the enzymes that terminate the process of de novo fatty acid synthesis by catalyzing the hydrolysis of the acyl-ACPs synthesized by fatty acid synthase. Fatty acid thioesterases can be classified into two families with distinct substrate specificities, namely FatA and FatB. Here, some new aspects of these enzymes have been studied, assessing how both enzymes contribute to the acyl composition of sunflower oil, not least through the changes in their expression during the process of seed filling. Moreover, the binding pockets of these enzymes were modeled based on new data from plant thioesterases, revealing important differences in their volume and geometry. Finally, the subcellular location of the two enzymes was evaluated and while both possess an N-terminal plastid transit peptide, only in FatB contains a hydrophobic sequence that could potentially serve as a transmembrane domain. Indeed, using in vivo imaging and organelle fractionation, H. annuus thioesterases, HaFatA and HaFatB, appear to be differentially localized in the plastid stroma and membrane envelope, respectively. The divergent roles fulfilled by HaFatA and HaFatB in oil biosynthesis are discussed in the light of our data.
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Affiliation(s)
- Jose A. Aznar-Moreno
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
| | - Rosario Sánchez
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Satinder K. Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | | | | | - Mónica Venegas Calerón
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Robert T. Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Joaquín J. Salas
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
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30
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Hernández Lozada NJ, Lai RY, Simmons TR, Thomas KA, Chowdhury R, Maranas CD, Pfleger BF. Highly Active C 8-Acyl-ACP Thioesterase Variant Isolated by a Synthetic Selection Strategy. ACS Synth Biol 2018; 7:2205-2215. [PMID: 30064208 DOI: 10.1021/acssynbio.8b00215] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Microbial metabolism is an attractive route for producing medium chain length fatty acids, e.g., octanoic acid, used in the oleochemical industry. One challenge to this strategy is the lack of enzymes that are both highly active in a microbial host and selective toward substrates with desired chain length. Of the many steps in fatty acid biosynthesis, the thioesterase is the most widely used enzyme for controlling chain length. Thioesterases hydrolyze the thioester bond between fatty acids and the acyl-carrier protein (ACP) or coenzyme A (CoA) cofactor. The functional role of thioesterases varies between organisms ( i.e., bacteria vs plant) and therefore so do the substrate specificities. As a result, microbial biocatalysts that utilize a heterologous thioesterase either produce high titers of fatty acids with mixed chain lengths or low titers of products with a narrow chain length distribution. To search for highly active enzymes that selectively hydrolyze octanoyl-ACP, we developed a genetic selection based on the lipoic acid requirement of Escherichia coli. We used the selection to identify variants in a randomly mutagenized library of the C8-specific Cuphea palustris FatB1 thioesterase. After optimizing expression of the thioesterase, E. coli cultures produced 1.7 g/L of octanoic acid with >90% specificity from a single chromosomal copy of this thioesterase. In vitro studies confirmed the mutant thioesterase possessed a 15-fold increase in kcat compared to its native sequence. The high level of specific activity allowed for low levels of expression while maintaining fatty acid titer. The low expression requirement will allow metabolic engineers to use more cellular resources to address other limitations in the pathway and maximize overall productivity.
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Affiliation(s)
- Néstor J. Hernández Lozada
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Rung-Yi Lai
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Trevor R. Simmons
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Kelsey A. Thomas
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Ratul Chowdhury
- Department of Chemical Engineering, Pennsylvania State University, 158 Fenske Laboratory, University Park, Pennsylvania 16802, United States
| | - Costas D. Maranas
- Department of Chemical Engineering, Pennsylvania State University, 158 Fenske Laboratory, University Park, Pennsylvania 16802, United States
| | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
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31
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Kalinger RS, Pulsifer IP, Rowland O. Elucidating the substrate specificities of acyl-lipid thioesterases from diverse plant taxa. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 127:104-118. [PMID: 29571003 DOI: 10.1016/j.plaphy.2018.03.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 05/21/2023]
Abstract
Acyl-ACP thioesterase enzymes, which cleave fatty acyl thioester bonds to release free fatty acids, contribute to much of the fatty acid diversity in plants. In Arabidopsis thaliana, a family of four single hot-dog fold domain, plastid-localized acyl-lipid thioesterases (AtALT1-4) generate medium-chain (C6-C14) fatty and β-keto fatty acids as secondary metabolites. These volatile products may serve to attract insect pollinators or deter predatory insects. Homologs of AtALT1-4 are present in all plant taxa, but are nearly all uncharacterized. Despite high sequence identity, AtALT1-4 generate different lipid products, suggesting that ALT homologs in other plants also have highly varied activities. We investigated the catalytic diversity of ALT-like thioesterases by screening the substrate specificities of 15 ALT homologs from monocots, eudicots, a lycophyte, a green microalga, and the ancient gymnosperm Gingko biloba, via expression in Escherichia coli. Overall, these enzymes had highly varied substrate preferences compared to one another and to AtALT1-4, and could be classified into four catalytic groups comprising members from diverse taxa. Group 1 ALTs primarily generated 14:1 β-keto fatty acids, Group 2 ALTs produced 6-10 carbon fatty/β-keto fatty acids, Group 3 ALTs predominantly produced 12-14 carbon fatty acids, and Group 4 ALTs mainly generated 16 carbon fatty acids. Enzymes in each group differed significantly in the quantities of lipids and types of minor products they generated in E. coli. Medium-chain fatty acids are used to manufacture insecticides, pharmaceuticals, and biofuels, and ALT-like proteins are ideal candidates for metabolic engineering to produce specific fatty acids in significant quantities.
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Affiliation(s)
- Rebecca S Kalinger
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Ian P Pulsifer
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Owen Rowland
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
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Sarria S, Bartholow TG, Verga A, Burkart MD, Peralta-Yahya P. Matching Protein Interfaces for Improved Medium-Chain Fatty Acid Production. ACS Synth Biol 2018; 7:1179-1187. [PMID: 29722970 DOI: 10.1021/acssynbio.7b00334] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Medium-chain fatty acids (MCFAs) are key intermediates in the synthesis of medium-chain chemicals including α-olefins and dicarboxylic acids. In bacteria, microbial production of MCFAs is limited by the activity and product profile of fatty acyl-ACP thioesterases. Here, we engineer a heterologous bacterial medium-chain fatty acyl-ACP thioesterase for improved MCFA production in Escherichia coli. Electrostatically matching the interface between the heterologous medium-chain Acinetobacter baylyi fatty acyl-ACP thioesterase (AbTE) and the endogenous E. coli fatty acid ACP ( E. coli AcpP) by replacing small nonpolar amino acids on the AbTE surface for positively charged ones increased secreted MCFA titers more than 3-fold. Nuclear magnetic resonance titration of E. coli 15N-octanoyl-AcpP with a single AbTE point mutant and the best double mutant showed a progressive and significant increase in the number of interactions when compared to AbTE wildtype. The best AbTE mutant produced 131 mg/L of MCFAs, with MCFAs being 80% of all secreted fatty acid chain lengths after 72 h. To enable the future screening of larger numbers of AbTE variants to further improve MCFA titers, we show that a previously developed G-protein coupled receptor (GPCR)-based MCFA sensor differentially detects MCFAs secreted by E. coli expressing different AbTE variants. This work demonstrates that engineering the interface of heterologous enzymes to better couple with endogenous host proteins is a useful strategy to increase the titers of microbially produced chemicals. Further, this work shows that GPCR-based sensors are producer microbe agnostic and can detect chemicals directly in the producer microbe supernatant, setting the stage for the sensor-guided engineering of MCFA producing microbes.
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Affiliation(s)
- Stephen Sarria
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Thomas G. Bartholow
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Adam Verga
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Pamela Peralta-Yahya
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Chimeric Fatty Acyl-Acyl Carrier Protein Thioesterases Provide Mechanistic Insight into Enzyme Specificity and Expression. Appl Environ Microbiol 2018; 84:AEM.02868-17. [PMID: 29549102 DOI: 10.1128/aem.02868-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 03/12/2018] [Indexed: 12/27/2022] Open
Abstract
Medium-chain fatty acids are commodity chemicals. Increasing and modifying the activity of thioesterases (TEs) on medium-chain fatty acyl-acyl carrier protein (acyl-ACP) esters may enable a high-yield microbial production of these molecules. The plant Cuphea palustris harbors two distinct TEs: C. palustris FatB1 (CpFatB1) (C8 specificity, lower activity) and CpFatB2 (C14 specificity, higher activity) with 78% sequence identity. We combined structural features from these two enzymes to create several chimeric TEs, some of which showed nonnatural fatty acid production as measured by an enzymatic assay and gas chromatography-mass spectrometry (GC-MS). Notably, chimera 4 exhibited an increased C8 fatty acid production in correlation with improved microbial expression. This chimera led us to identify CpFatB2-specific amino acids between positions 219 and 272 that lead to higher protein levels. Chimera 7 produced a broad range of fatty acids and appeared to combine a fatty acid binding pocket with long-chain specificity and an ACP interaction site that may activate fatty acid extrusion. Using homology modeling and in silico docking with ACP, we identified a "positive patch" within amino acids 162 to 218, which may direct the ACP interaction and regulate access to short-chain fatty acids. On the basis of this modeling, we transplanted putative ACP interaction sequences from CpFatB1 into CpFatB2 and created a chimeric thioesterase that produced medium-chain as well as long-chain fatty acids. Thus, the engineering of chimeric enzymes and characterizing their microbial activity and chain-length specificity suggested mechanistic insights into TE functions and also generated thioesterases with potentially useful properties. These observations may inform a rational engineering of TEs to allow alkyl chain length control.IMPORTANCE Medium-chain fatty acids are important commodity chemicals. These molecules are used as plastic precursors and in shampoos and other detergents and could be used as biofuel precursors if production economics were favorable. Hydrocarbon-based liquid fuels must be optimized to have a desired boiling point, low freezing point, low viscosity, and other physical characteristics. Similarly, the solubility and harshness of detergents and the flexibility of plastic polymers can be modulated. The length and distribution of the carbon chains in the hydrophobic tails determine these properties. The biological synthesis of cell membranes and fatty acids produces chains of primarily 16 to 18 carbons, which give rise to current biofuels. The ultimate goal of the work presented here is to engineer metabolic pathways to produce designer molecules with the correct number of carbons in a chain, so that such molecules could be used directly as specialty commodity chemicals or as fuels after minimal processing.
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Tuning of acyl-ACP thioesterase activity directed for tailored fatty acid synthesis. Appl Microbiol Biotechnol 2018; 102:3173-3182. [DOI: 10.1007/s00253-018-8770-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/03/2018] [Accepted: 01/05/2018] [Indexed: 12/16/2022]
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