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Pöschel L, Guevara-Martínez M, Hörnström D, van Maris AJA, Buchhaupt M. Engineering of thioesterase YciA from Haemophilus influenzae for production of carboxylic acids. Appl Microbiol Biotechnol 2023; 107:6219-6236. [PMID: 37572123 PMCID: PMC10560148 DOI: 10.1007/s00253-023-12691-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 08/14/2023]
Abstract
Acyl-CoA-thioesterases, which hydrolyze acyl-CoA-esters and thereby release the respective acid, have essential functions in cellular metabolism and have also been used to produce valuable compounds in biotechnological processes. Thioesterase YciA originating from Haemophilus influenzae has been previously used to produce specific dicarboxylic acids from CoA-bound intermediates of the ethylmalonyl CoA pathway (EMCP) in Methylorubrum extorquens. In order to identify variants of the YciA enzyme with the capability to hydrolyze so far inaccessible CoA-esters of the EMCP or with improved productivity, we engineered the substrate-binding region of the enzyme. Screening a small semi-rational mutant library directly in M. extorquens yielded the F35L variant which showed a drastic product level increase for mesaconic acid (6.4-fold) and 2-methylsuccinic acid (4.4-fold) compared to the unaltered YciA enzyme. Unexpectedly, in vitro enzyme assays using respective M. extorquens cell extracts or recombinantly produced thioesterases could not deliver congruent data, as the F35L variant showed strongly reduced activity in these experiments. However, applied in an Escherichia coli production strain, the protein variant again outperformed the wild-type enzyme by allowing threefold increased 3-hydroxybutyric acid product titers. Saturation mutagenesis of the codon for position 35 led to the identification of another highly efficient YciA variant and enabled structure-function interpretations. Our work describes an important module for dicarboxylic acid production with M. extorquens and can guide future thioesterase improvement approaches. KEY POINTS: • Substitutions at position F35 of YciAHI changed the productivity of YciA-based release of carboxylic acid products in M. extorquens AM1 and E. coli. • YciAHI F35N and F35L are improved variants for dicarboxylic production of 2-methylsuccinic acid and mesaconic acid with M. extorquens AM1. • In vitro enzyme assays did not reveal superior properties of the optimized protein variants.
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Affiliation(s)
- Laura Pöschel
- DECHEMA-Forschungsinstitut, Microbial Biotechnology, Theodor-Heuss-Allee 25, 60486, Frankfurt Am Main, Germany
- Faculty of Biological Sciences, Goethe University Frankfurt, Max-Von-Laue-Str. 9, 60438, Frankfurt Am Main, Germany
| | - Mónica Guevara-Martínez
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, SE 10691, Stockholm, Sweden
| | - David Hörnström
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, SE 10691, Stockholm, Sweden
| | - Antonius J A van Maris
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, SE 10691, Stockholm, Sweden
| | - Markus Buchhaupt
- DECHEMA-Forschungsinstitut, Microbial Biotechnology, Theodor-Heuss-Allee 25, 60486, Frankfurt Am Main, Germany.
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2
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Liu J, Mandlaa, Wang J, Sun Z, Chen Z. A strategy to enhance and modify fatty acid synthesis in Corynebacterium glutamicum and Escherichia coli: overexpression of acyl-CoA thioesterases. Microb Cell Fact 2023; 22:191. [PMID: 37735384 PMCID: PMC10512533 DOI: 10.1186/s12934-023-02189-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/30/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND Fatty acid (FA) is an important platform compound for the further synthesis of high-value biofuels and oleochemicals, but chemical synthesis of FA has many limitations. One way to meet the future demand for FA could be to use microbial cell factories for FA biosynthesis. RESULTS Thioesterase (TE; TesA, TesB, and TE9) of Corynebacterium glutamicum (CG) can potentially improve FA biosynthesis, and tesA, tesB, and te9 were overexpressed in C. glutamicum and Escherichia coli (EC), respectively, in this study. The results showed that the total fatty acid (TFA) production of CGtesB and ECtesB significantly increased to 180.52 mg/g dry cell weight (DCW) and 123.52 mg/g DCW, respectively (P < 0.05). Overexpression strains CG and EC could increase the production of C16:0, C18:1(t), C18:2, C20:1, C16:1, C18:0, and C18:1(c) (P < 0.05), respectively, and the changes of long-chain FA resulted in the enhancement of TFA production. The enzymatic properties of TesA, TesB, and TE9 in vitro were determined: they were specific for long-, broad and short-chain substrates, respectively; the optimal temperature was 30.0 °C and the optimal acid-base (pH) were 8.0, 8.0, and 9.0, respectively; they were inhibited by Fe2+, Cu2+, Zn2+, Mg2+, and K+. CONCLUSION Overexpression TE enhances and modifies FA biosynthesis with multiple productive applications, and the enzyme properties provided useful clues for optimizing FA synthesis.
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Affiliation(s)
- Jin Liu
- Food Science and Engineering College, Inner Mongolia Agricultural University, 306 Zhaowood Road, Saihan District, Hohhot, 010018, Inner Mongolia, China
| | - Mandlaa
- Food Science and Engineering College, Inner Mongolia Agricultural University, 306 Zhaowood Road, Saihan District, Hohhot, 010018, Inner Mongolia, China
| | - Jia Wang
- Food Science and Engineering College, Inner Mongolia Agricultural University, 306 Zhaowood Road, Saihan District, Hohhot, 010018, Inner Mongolia, China
| | - Ziyu Sun
- Food Science and Engineering College, Inner Mongolia Agricultural University, 306 Zhaowood Road, Saihan District, Hohhot, 010018, Inner Mongolia, China.
| | - Zhongjun Chen
- Food Science and Engineering College, Inner Mongolia Agricultural University, 306 Zhaowood Road, Saihan District, Hohhot, 010018, Inner Mongolia, China.
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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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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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Hickman TWP, Baud D, Benhamou L, Hailes HC, Ward JM. Characterisation of four hotdog-fold thioesterases for their implementation in a novel organic acid production system. Appl Microbiol Biotechnol 2020; 104:4397-4406. [PMID: 32193574 PMCID: PMC7190597 DOI: 10.1007/s00253-020-10519-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 02/23/2020] [Accepted: 03/03/2020] [Indexed: 11/24/2022]
Abstract
With increasing interest in the diverse properties of organic acids and their application in synthetic pathways, developing biological tools for producing known and novel organic acids would be very valuable. In such a system, organic acids may be activated as coenzyme A (CoA) esters, then modified by CoA-dependent enzymes, followed by CoA liberation by a broad-acting thioesterase. This study has focused on the identification of suitable thioesterases (TE) for utilisation in such a pathway. Four recombinant hotdog-fold TEs were screened with a range of CoA esters in order to identify a highly active, broad spectrum TE. The TesB-like TE, RpaL, from Rhodopseudomonas palustris was found to be able to use aromatic, alicyclic and both long and short aliphatic CoA esters. Size exclusion chromatography, revealed RpaL to be a monomer of fused hotdog domains, in contrast to the complex quaternary structures found with similar TesB-like TEs. Nonetheless, sequence alignments showed a conserved catalytic triad despite the variation in quaternary arrangement. Kinetic analysis revealed a preference towards short-branched chain CoA esters with the highest specificity towards DL-β-hydroxybutyryl CoA (1.6 × 104 M−1 s−1), which was found to decrease as the acyl chain became longer and more functionalised. Substrate inhibition was observed with the fatty acyl n-heptadecanoyl CoA at concentrations exceeding 0.3 mM; however, this was attributed to its micellar aggregation properties. As a result of the broad activity observed with RpaL, it is a strong candidate for implementation in CoA ester pathways to generate modified or novel organic acids.
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Affiliation(s)
- T W P Hickman
- Department of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - D Baud
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - L Benhamou
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - H C Hailes
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - J M Ward
- Department of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK.
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Khandokar Y, Srivastava P, Raidal S, Sarker S, Forwood JK. Structural basis for disulphide-CoA inhibition of a butyryl-CoA hexameric thioesterase. J Struct Biol 2020; 210:107477. [PMID: 32027968 DOI: 10.1016/j.jsb.2020.107477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/30/2020] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
Acyl-coenzyme A thioesterases (ACTs) catalyse the hydrolysis of thioester bonds between fatty-acyl chains and coenzyme A (CoA), producing a free fatty-acyl chain and CoA. These enzymes are expressed ubiquitously across prokaryotes and eukaryotes, and play important roles in lipid metabolism. There are 25 thioesterase families, subdivided based on their active site configuration, protein oligomerization, and substrate specificity. Understanding the mechanism of regulation within these families is important due to their roles in controlling the cell concentration of a range of fatty acids and CoA-bound compounds. Here we report a structural basis for a novel mode of inhibition of an ACT from Staphylococcus aureus. The enzyme displays a hotdog fold composed of five β-strands wrapping around a central α-helix, and an additional 30 residue α-helix located at its C-terminus. We show that the enzyme is a hexamer and has specificity towards butyryl-CoA. Structural analysis revealed putative catalytic residues, and we show through site directed mutagenesis that Asn28, Asp43, and Thr60 are critical for activity. Additionally, we show that the Asn28Ala destabilises the enzyme oligomeric state into two distinct populations. Co-crystallization of the enzyme with the substrate butyryl-CoA produced a crystal with three CoA ligands bound in the enzyme active sites: CoA, butyryl-CoA, and disulphide-CoA, the latter of which inhibits enzyme activity. Our study provides new insights into the structure and specificity of hexameric thioesterases, inhibitory feedback mechanisms, and possible biotechnological applications in short-chain fatty acid production such as biofuels, pharmaceuticals, and industrial compounds.
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Affiliation(s)
- Yogesh Khandokar
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, 3052 Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Parul Srivastava
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Shane Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Subir Sarker
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC 3086, Australia
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
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7
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Multidimensional engineering of Saccharomyces cerevisiae for efficient synthesis of medium-chain fatty acids. Nat Catal 2020. [DOI: 10.1038/s41929-019-0409-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Swarbrick CMD, Bythrow GV, Aragao D, Germain GA, Quadri LEN, Forwood JK. Mycobacteria Encode Active and Inactive Classes of TesB Fatty-Acyl CoA Thioesterases Revealed through Structural and Functional Analysis. Biochemistry 2017; 56:1460-1472. [PMID: 28156101 DOI: 10.1021/acs.biochem.6b01049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacteria contain a large number of highly divergent species and exhibit unusual lipid metabolism profiles, believed to play important roles in immune invasion. Thioesterases modulate lipid metabolism through the hydrolysis of activated fatty-acyl CoAs; multiple copies are present in mycobacteria, yet many remain uncharacterized. Here, we undertake a comprehensive structural and functional analysis of a TesB thioesterase from Mycobacterium avium (MaTesB). Structural superposition with other TesB thioesterases reveals that the Asp active site residue, highly conserved across a wide range of TesB thioesterases, is mutated to Ala. Consistent with these structural data, the wild-type enzyme failed to hydrolyze an extensive range of acyl-CoA substrates. Mutation of this residue to an active Asp residue restored activity against a range of medium-chain length fatty-acyl CoA substrates. Interestingly, this Ala mutation is highly conserved across a wide range of Mycobacterium species but not found in any other bacteria or organism. Our structural homology analysis revealed that at least one other TesB acyl-CoA thioesterase also contains an Ala residue at the active site, while two other Mycobacterium TesB thioesterases harbor an Asp residue at the active site. The inactive TesBs display a common quaternary structure that is distinct from that of the active TesB thioesterases. Investigation of the effect of expression of either the catalytically active or inactive MaTesB in Mycobacterium smegmatis exposed, to the best of our knowledge, the first genotype-phenotype association implicating a mycobacterial tesB gene. This is the first report that mycobacteria encode active and inactive forms of thioesterases, the latter of which appear to be unique to mycobacteria.
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Affiliation(s)
- Crystall M D Swarbrick
- School of Biomedical Sciences, Charles Sturt University , Wagga Wagga, New South Wales 2678, Australia
| | - Glennon V Bythrow
- Department of Biology, Brooklyn College, City University of New York , 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Biology Program, Graduate Center, City University of New York , 365 Fifth Avenue, New York, New York 10016, United States
| | - David Aragao
- Australian Synchrotron , 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Gabrielle A Germain
- Department of Biology, Brooklyn College, City University of New York , 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Biology Program, Graduate Center, City University of New York , 365 Fifth Avenue, New York, New York 10016, United States
| | - Luis E N Quadri
- Department of Biology, Brooklyn College, City University of New York , 2900 Bedford Avenue, Brooklyn, New York 11210, United States.,Biology and Biochemistry Programs, Graduate Center, City University of New York , 365 Fifth Avenue, New York, New York 10016, United States
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University , Wagga Wagga, New South Wales 2678, Australia
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