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Abstract
Fatty acid (FA) biosynthesis plays a central role in the metabolism of living cells as building blocks of biological membranes, energy reserves of the cell, and precursors to second messenger molecules. In keeping with its central metabolic role, FA biosynthesis impacts several cellular functions and its misfunction is linked to disease, such as cancer, obesity, and non-alcoholic fatty liver disease. Cellular FA biosynthesis is conducted by fatty acid synthases (FAS). All FAS enzymes catalyze similar biosynthetic reactions, but the functional architectures adopted by these cellular catalysts can differ substantially. This variability in FAS structure amongst various organisms and the essential role played by FA biosynthetic pathways makes this metabolic route a valuable target for the development of antibiotics. Beyond cellular FA biosynthesis, the quest for renewable energy sources has piqued interest in FA biosynthetic pathway engineering to generate biofuels and fatty acid derived chemicals. For these applications, based on FA biosynthetic pathways, to succeed, detailed metabolic, functional and structural insights into FAS are required, along with an intimate knowledge into the regulation of FAS. In this review, we summarize our present knowledge about the functional, structural, and regulatory aspects of FAS.
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Affiliation(s)
- Aybeg N Günenc
- Research Group for Structural Biochemistry and Mechanisms, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Benjamin Graf
- Research Group for Structural Biochemistry and Mechanisms, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Holger Stark
- Department of Structural Dynamics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ashwin Chari
- Research Group for Structural Biochemistry and Mechanisms, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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Xie X, Garg A, Keatinge-Clay AT, Khosla C, Cane DE. Epimerase and Reductase Activities of Polyketide Synthase Ketoreductase Domains Utilize the Same Conserved Tyrosine and Serine Residues. Biochemistry 2016; 55:1179-86. [PMID: 26863427 DOI: 10.1021/acs.biochem.6b00024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The role of the conserved active site tyrosine and serine residues in epimerization catalyzed by polyketide synthase ketoreductase (PKS KR) domains has been investigated. Both mutant and wild-type forms of epimerase-active KR domains, including the intrinsically redox-inactive EryKR3° and PicKR3° as well as redox-inactive mutants of EryKR1, were incubated with [2-(2)H]-(2R,3S)-2-methyl-3-hydroxypentanoyl-SACP ([2-(2)H]-2) and 0.05 equiv of NADP(+) in the presence of the redox-active, epimerase-inactive EryKR6 domain. The residual epimerase activity of each mutant was determined by tandem equilibrium isotope exchange, in which the first-order, time-dependent washout of isotope from 2 was monitored by liquid chromatography-tandem mass spectrometry with quantitation of the deuterium content of the diagnostic pantetheinate ejection fragment (4). Replacement of the active site Tyr or Ser residues, alone or together, significantly reduced the observed epimerase activity of each KR domain with minimal effect on substrate binding. Our results demonstrate that the epimerase and reductase activities of PKS KR domains share a common active site, with both reactions utilizing the same pair of Tyr and Ser residues.
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Affiliation(s)
- Xinqiang Xie
- Department of Chemistry, Box H, Brown University , Providence, Rhode Island 02912-9108, United States
| | - Ashish Garg
- Department of Chemistry, Box H, Brown University , Providence, Rhode Island 02912-9108, United States
| | - Adrian T Keatinge-Clay
- Departments of Molecular Biosciences and Chemistry, The University of Texas at Austin , 1 University Station A5300, Austin, Texas 78712-0165, United States
| | - Chaitan Khosla
- Departments of Chemical Engineering, Chemistry, and Biochemistry, Stanford University , Stanford, California 94305, United States
| | - David E Cane
- Department of Chemistry, Box H, Brown University , Providence, Rhode Island 02912-9108, United States
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Beld J, Lee DJ, Burkart MD. Fatty acid biosynthesis revisited: structure elucidation and metabolic engineering. MOLECULAR BIOSYSTEMS 2015; 11:38-59. [PMID: 25360565 PMCID: PMC4276719 DOI: 10.1039/c4mb00443d] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fatty acids are primary metabolites synthesized by complex, elegant, and essential biosynthetic machinery. Fatty acid synthases resemble an iterative assembly line, with an acyl carrier protein conveying the growing fatty acid to necessary enzymatic domains for modification. Each catalytic domain is a unique enzyme spanning a wide range of folds and structures. Although they harbor the same enzymatic activities, two different types of fatty acid synthase architectures are observed in nature. During recent years, strained petroleum supplies have driven interest in engineering organisms to either produce more fatty acids or specific high value products. Such efforts require a fundamental understanding of the enzymatic activities and regulation of fatty acid synthases. Despite more than one hundred years of research, we continue to learn new lessons about fatty acid synthases' many intricate structural and regulatory elements. In this review, we summarize each enzymatic domain and discuss efforts to engineer fatty acid synthases, providing some clues to important challenges and opportunities in the field.
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Affiliation(s)
- Joris Beld
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.
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Sun YH, Cheng Q, Tian WX, Wu XD. A substitutive substrate for measurements of beta-ketoacyl reductases in two fatty acid synthase systems. ACTA ACUST UNITED AC 2007; 70:850-6. [PMID: 18201766 DOI: 10.1016/j.jbbm.2007.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 10/13/2007] [Accepted: 10/15/2007] [Indexed: 11/25/2022]
Abstract
Bacterial beta-ketoacyl-ACP reductase (FabG) and the beta-ketoacyl reductase domain in mammalian fatty acid synthase (FAS) have the same function and both are rendered as the novel targets for drugs. Herein we developed a convenient method, using an available compound ethyl acetoacetate (EAA) as the substitutive substrate, to measure their activities by monitoring decrease of NADPH absorbance at 340 nm. In addition to the result, ethyl 3-hydroxybutyrate (EHB) was detected by HPLC analysis in the reaction system, indicating that EAA worked effectively as the substrate of FabG and FAS since its beta-keto group was reduced. Then, the detailed kinetic characteristics, such as optimal ionic strength, pH value and temperature, and kinetic parameters, for FabG and FAS with this substitutive substrate were determined. The Km and kcat values of FabG obtained for EAA were 127 mM and 0.30 s(-1), while those of this enzyme for NADPH were 10.0 microM and 0.59 s(-1), respectively. The corresponding Km and kcat values of FAS were 126 mM and 4.63 s(-1) for EAA; 8.7 microM and 4.09 s(-1) for NADPH. Additionally, the inhibitory kinetics of FabG and FAS, by a known inhibitor EGCG, was also studied.
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Affiliation(s)
- Ying-Hui Sun
- Department of Biology, Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China
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Udwary DW, Merski M, Townsend CA. A method for prediction of the locations of linker regions within large multifunctional proteins, and application to a type I polyketide synthase. J Mol Biol 2002; 323:585-98. [PMID: 12381311 PMCID: PMC3400148 DOI: 10.1016/s0022-2836(02)00972-5] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Multifunctional proteins often appear to result from fusion of smaller proteins and in such cases typically can be separated into their ancestral components simply by cleaving the linker regions that separate the domains. Though possibly guided by sequence alignment, structural evidence, or light proteolysis, determination of the locations of linker regions remains empirical. We have developed an algorithm, named UMA, to predict the locations of linker regions in multifunctional proteins by quantification of the conservation of several properties within protein families, and the results agree well with structurally characterized proteins. This technique has been applied to a family of fungal type I iterative polyketide synthases (PKS), allowing prediction of the locations of all of the standard PKS domains, as well as two previously unidentified domains. Using these predictions, we report the cloning of the first fragment from the PKS norsolorinic acid synthase, responsible for biosynthesis of the first isolatable intermediate in aflatoxin production. The expression, light proteolysis and catalytic abilities of this acyl carrier protein-thioesterase didomain are discussed.
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Ming D, Kong Y, Wakil SJ, Brink J, Ma J. Domain movements in human fatty acid synthase by quantized elastic deformational model. Proc Natl Acad Sci U S A 2002; 99:7895-9. [PMID: 12060737 PMCID: PMC122991 DOI: 10.1073/pnas.112222299] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2002] [Accepted: 04/12/2002] [Indexed: 11/18/2022] Open
Abstract
This paper reports the results of applying a computational method called the quantized elastic deformational model, to the determination of conformational flexibility of the supermolecular complex of human fatty acid synthase. The essence of this method is the ability to model large-scale conformational changes such as domain movements by treating the protein as an elastic object without the knowledge of protein primary sequence and atomic coordinates. The calculation was based on the electron density maps of the synthase at 19 A. The results suggest that the synthase is a very flexible molecule. Two types of flexible hinges in the structure were identified. One is an intersubunit hinge formed by the intersubunit connection and the other is an intrasubunit hinge located between domains I and II. Despite the fact that the dimeric synthase has a chemically symmetric structure, large domain movements around the hinge region occur in various directions and allow the molecule to adopt a wide range of conformations. These domain movements are likely to be important in facilitating and regulating the entire palmitate synthesis by coordinating the communication between components of the molecule, for instance, adjusting the distance between various active sites inside the catalytic reaction center. Finally, the ability to describe protein motions of a supermolecular complex, without the information of protein sequence and atomic coordinates, is a major advance in computational modeling of protein dynamics. The method provides an unprecedented ability to model protein motions at such a low resolution of structure.
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Affiliation(s)
- Dengming Ming
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, BCM-125, Houston, TX 77030, USA
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Chirala SS, Jayakumar A, Gu ZW, Wakil SJ. Human fatty acid synthase: role of interdomain in the formation of catalytically active synthase dimer. Proc Natl Acad Sci U S A 2001; 98:3104-8. [PMID: 11248039 PMCID: PMC30614 DOI: 10.1073/pnas.051635998] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human and animal fatty acid synthases are dimers of two identical multifunctional proteins (M(r) 272,000) arranged in an antiparallel configuration. This arrangement generates two active centers for fatty acid synthesis separated by interdomain (ID) regions and predicts that two appropriate halves of the monomer should be able to reconstitute an active fatty acid synthesizing center. This prediction was confirmed by the reconstitution of the synthase active center by using two heterologously expressed halves of the monomer protein. Each of these recombinant halves of synthase monomer contains half of the ID regions. We show here that the fatty acid synthase activity could not be reconstituted when the ID sequences present in the two recombinant halves are deleted, suggesting that these ID sequences are essential for fatty acid synthase dimer formation. Further, we confirm that the ID sequences are the only regions of fatty acid synthase monomers that showed significant dimer formation, by using the yeast two-hybrid system. These results are consistent with the proposal that the ID region, which has no known catalytic activity, associates readily and holds together the two dynamic active centers of the fatty acid synthase dimer, therefore playing an important role in the architecture of catalytically active fatty acid synthase.
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Affiliation(s)
- S S Chirala
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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8
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Barry CE, Lee RE, Mdluli K, Sampson AE, Schroeder BG, Slayden RA, Yuan Y. Mycolic acids: structure, biosynthesis and physiological functions. Prog Lipid Res 1998; 37:143-79. [PMID: 9829124 DOI: 10.1016/s0163-7827(98)00008-3] [Citation(s) in RCA: 388] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- C E Barry
- Tuberculosis Research Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA.
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Tropf S, Revill WP, Bibb MJ, Hopwood DA, Schweizer M. Heterologously expressed acyl carrier protein domain of rat fatty acid synthase functions in Escherichia coli fatty acid synthase and Streptomyces coelicolor polyketide synthase systems. CHEMISTRY & BIOLOGY 1998; 5:135-46. [PMID: 9545424 DOI: 10.1016/s1074-5521(98)90058-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Fatty acid synthases (FASs) catalyze the de novo biosynthesis of long-chain saturated fatty acids by a process common to eubacteria and eukaryotes, using either a set of monofunctional proteins (Type II FAS) or a polypeptide containing several catalytic functions (Type I FAS). To compare the features of a Type I domain with its Type II counterpart we expressed and characterized an acyl carrier protein (ACP) domain of the Type I rat FAS. RESULTS An ACP domain of rat FAS was defined that allows expression of a small percentage of active holo-ACP both in Escherichia coli, increasing fivefold upon co-expression with an E. coli holo-ACP synthase, and in Streptomyces coelicolor. The rat ACP domain functions with some components of the E. coli FAS, and can replace the actinorhodin polyketide synthase (PKS) ACP in S. coelicolorA3(2). Purification of the rat ACP domain from E. coli resulted in loss of its functionality. Purified apo-ACP could be converted to its holo-form upon incubation with purified E. coli holo-ACP synthase in vitro, however, suggesting that the loss of functionality was not due to a conformational change. CONCLUSIONS Functionality of the recombinant rat ACP was shown in distantly related and diverse enzyme systems, suggesting that Type I and Type II ACPs have a similar conformation. A procedure was described that might permit the production of rat FAS holo-ACP for structural and further biochemical characterization.
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Affiliation(s)
- S Tropf
- Genetics and Microbiology Department, Institute of Food Research, Colney, UK
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Jayakumar A, Chirala SS, Wakil SJ. Human fatty acid synthase: assembling recombinant halves of the fatty acid synthase subunit protein reconstitutes enzyme activity. Proc Natl Acad Sci U S A 1997; 94:12326-30. [PMID: 9356448 PMCID: PMC24928 DOI: 10.1073/pnas.94.23.12326] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Our model of the native fatty acid synthase (FAS) depicts it as a dimer of two identical multifunctional proteins (Mr approximately 272,000) arranged in an antiparallel configuration so that the active Cys-SH of the beta-ketoacyl synthase of one subunit (where the acyl group is attached) is juxtaposed within 2 A of the pantetheinyl-SH of the second subunit (where the malonyl group is bound). This arrangement generates two active centers for fatty acid synthesis and predicts that if we have two appropriate halves of the monomer, we should be able to reconstitute an active fatty acid-synthesizing site. We cloned, expressed, and purified catalytically active thioredoxin (TRX) fusion proteins of the NH2-terminal half of the human FAS subunit protein (TRX-hFAS-dI; residues 1-1,297; Mr approximately 166) and of the C-terminal half (TRX-hFAS-dII-III; residues 1,296-2,504; Mr approximately 155). Adding equivalent amounts of TRX-hFAS-dI and TRX-hFAS-dII-III to a reaction mixture containing acetyl-CoA, malonyl-CoA, and NADPH resulted in the synthesis of long-chain fatty acids. The rate of synthesis was dependent upon the presence of both recombinant proteins and reached a constant level when they were present in equivalent amounts, indicating that the reconstitution of an active fatty acid-synthesizing site required the presence of every partial activity associated with the subunit protein. Analyses of the product acids revealed myristate to be the most abundant with small amounts of palmitate and stearate, possibly because of the way the fused recombinant proteins interacted with each other so that the thioesterase hydrolyzed the acyl group in its myristoyl state. The successful reconstitution of the human FAS activity from its domain I and domains II and III fully supports our model for the structure-function relationship of FAS in animal tissues.
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Affiliation(s)
- A Jayakumar
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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11
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Gu P, Welch WH, Guo L, Schegg KM, Blomquist GJ. Characterization of a novel microsomal fatty acid synthetase (FAS) compared to a cytosolic FAS in the housefly, Musca domestica. Comp Biochem Physiol B Biochem Mol Biol 1997; 118:447-56. [PMID: 9440236 DOI: 10.1016/s0305-0491(97)00112-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A novel membrane-bound fatty acid synthetase (FAS) associated with the microsomal fraction from the housefly, Musca domestica, was solubilized and purified to homogeneity. The microsomal FAS was solubilized by 0.75 M KCl in phosphate buffer and was purified to homogeneity by the sequential use of ammonium sulfate precipitation followed by Sepharose CL-6B, DEAE Sephacel and Red Agarose (dye ligand affinity) chromatography. The specific activity of the microsomal FAS was increased 1,440-fold to 6,522 U/mg during purification. The cytosolic FAS from the housefly was also purified by similar methods and the specific activity increased 183-fold to 7,533 U/mg. The relative molecular mass of the microsomal and cytosolic FAS are 419 +/- 22 kDa and 405 +/- 18 kDa, respectively, for the dimers as determined by gel permeation chromatography. The microsomal and the cytosolic FAS yield different tryptic digestion maps and have slightly different amino acid compositions, which demonstrate structural differences between the two FASs. In addition, there are differences between the two FASs in their kinetic characteristics and their ability to incorporate methylmalonylCoA into the growing fatty acyl chain.
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Affiliation(s)
- P Gu
- Department of Biochemistry/MS 330, University of Nevada, Reno 89557-0014, USA
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Chuck JA, McPherson M, Huang H, Jacobsen JR, Khosla C, Cane DE. Molecular recognition of diketide substrates by a beta-ketoacyl-acyl carrier protein synthase domain within a bimodular polyketide synthase. CHEMISTRY & BIOLOGY 1997; 4:757-66. [PMID: 9375254 DOI: 10.1016/s1074-5521(97)90314-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Modular polyketide synthases (PKSs) are large multifunctional proteins that catalyze the biosynthesis of structurally complex bioactive products. The modular organization of PKSs has allowed the application of a combinatorial approach to the synthesis of novel polyketides via the manipulation of these biocatalysts at the genetic level. The inherent specificity of PKSs for their natural substrates, however, may place limits on the spectrum of molecular diversity that can be achieved in polyketide products. With the aim of further understanding PKS specificity, as a route to exploiting PKSs in combinatorial synthesis, we chose to examine the substrate specificity of a single intact domain within a bimodular PKS to investigate its capacity to utilize unnatural substrates. RESULTS We used a blocked mutant of a bimodular PKS in which formation of the triketide product could occur only via uptake and processing of a synthetic diketide intermediate. By introducing systematic changes in the native diketide structure, by means of the synthesis of unnatural diketide analogs, we have shown that the ketosynthase domain of module 2 (KS2 domain) in 6-deoxyerythronolide B synthase (DEBS) tolerates a broad range of variations in substrate structure, but it strongly discriminates against some others. CONCLUSIONS Defining the boundaries of substrate recognition within PKS domains is crucial to the rationally engineered biosynthesis of novel polyketide products, many of which could be prepared only with great difficulty, if at all, by direct chemical synthesis or semi-synthesis. Our results suggest that the KS2 domain of DEBS1 has a relatively relaxed specificity that can be exploited for the design and synthesis of medicinally important polyketide products.
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Affiliation(s)
- J A Chuck
- Department of Chemistry, Brown University, Providence, RI 02912-9108, USA
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Jayakumar A, Huang WY, Raetz B, Chirala SS, Wakil SJ. Cloning and expression of the multifunctional human fatty acid synthase and its subdomains in Escherichia coli. Proc Natl Acad Sci U S A 1996; 93:14509-14. [PMID: 8962082 PMCID: PMC26163 DOI: 10.1073/pnas.93.25.14509] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/1996] [Indexed: 02/03/2023] Open
Abstract
We engineered a full-length (8.3-kbp) cDNA coding for fatty acid synthase (FAS; EC 2.3.1.85) from the human brain FAS cDNA clones we characterized previously. In the process of accomplishing this task, we developed a novel PCR procedure, recombinant PCR, which is very useful in joining two overlapping DNA fragments that do not have a common or unique restriction site. The full-length cDNA was cloned in pMAL-c2 for heterologous expression in Escherichia coli as a maltose-binding protein fusion. The recombinant protein was purified by using amylose-resin affinity and hydroxylapatite chromatography. As expected from the coding capacity of the cDNA expressed, the chimeric recombinant protein has a molecular weight of 310,000 and reacts with antibodies against both human FAS and maltose-binding protein. The maltose-binding protein-human FAS (MBP-hFAS) catalyzed palmitate synthesis from acetyl-CoA, malonyl-CoA, and NADPH and exhibited all of the partial activities of FAS at levels comparable with those of the native human enzyme purified from HepG2 cells. Like the native HepG2 FAS, the products of MBP-hFAS are mainly palmitic acid (> 90%) and minimal amounts of stearic and arachidic acids. Similarly, a human FAS cDNA encoding domain I (beta-ketoacyl synthase, acetyl-CoA and malonyl-CoA transacylases, and beta-hydroxyacyl dehydratase) was cloned and expressed in E. coli using pMAL-c2. The expressed fusion protein, MBP-hFAS domain I, was purified to apparent homogeneity (M(r) 190,000) and exhibited the activities of the acetyl/malonyl transacylases and the beta-hydroxyacyl dehydratase. In addition, a human FAS cDNA encoding domains II and III (enoyl and beta-ketoacyl reductases, acyl carrier protein, and thioesterase) was cloned in pET-32b(+) and expressed in E. coli as a fusion protein with thioredoxin and six in-frame histidine residues. The recombinant fusion protein, thioredoxin-human FAS domains II and III, that was purified from E. coli had a molecular weight of 159,000 and exhibited the activities of the enoyl and beta-ketoacyl reductases and the thioesterase. Both the MBP and the thioredoxin-His-tags do not appear to interfere with the catalytic activity of human FAS or its partial activities.
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Affiliation(s)
- A Jayakumar
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030, USA
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14
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Lambalot RH, Gehring AM, Flugel RS, Zuber P, LaCelle M, Marahiel MA, Reid R, Khosla C, Walsh CT. A new enzyme superfamily - the phosphopantetheinyl transferases. CHEMISTRY & BIOLOGY 1996; 3:923-36. [PMID: 8939709 DOI: 10.1016/s1074-5521(96)90181-7] [Citation(s) in RCA: 625] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND All polyketide synthases, fatty acid synthases, and non-ribosomal peptide synthetases require posttranslational modification of their constituent acyl carrier protein domain(s) to become catalytically active. The inactive apoproteins are converted to their active holo-forms by posttranslational transfer of the 4'-phosphopantetheinyl (P-pant) moiety of coenzyme A to the sidechain hydroxyl of a conserved serine residue in each acyl carrier protein domain. The first P-pant transferase to be cloned and characterized was the recently reported Escherichia coli enzyme ACPS, responsible for apo to holo conversion of fatty acid synthase. Surprisingly, initial searches of sequence databases did not reveal any proteins with significant peptide sequence similarity with ACPS. RESULTS Through refinement of sequence alignments that indicated low level similarity with the ACPS peptide sequence, we identified two consensus motifs shared among several potential ACPS homologs. This has led to the identification of a large family of proteins having 12-22 % similarity with ACPS, which are putative P-pant transferases. Three of these proteins, E. coli EntD and o195, and B. subtilis Sfp, have been overproduced, purified and found to have P-pant transferase activity, confirming that the observed low level of sequence homology correctly predicted catalytic function. Three P-pant transferases are now known to be present in E. coli (ACPS, EntD and o195); ACPS and EntD are specific for the activation of fatty acid synthase and enterobactin synthetase, respectively. The apo-protein substrate for o195 has not yet been identified. Sfp is responsible for the activation of the surfactin synthetase. CONCLUSIONS The specificity of ACPS and EntD for distinct P-pant-requiring enzymes suggests that each P-pant-requiring synthase has its own partner enzyme responsible for apo to holo activation of its acyl carrier domains. This is the first direct evidence that in organisms containing multiple P-pant-requiring pathways, each pathway has its own posttranslational modifying activity.
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Affiliation(s)
- R H Lambalot
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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Selective inhibition of R-enzymes by simple organic acids in yeast-catalysed reduction of ethyl 3-oxobutanoate. Enzyme Microb Technol 1991. [DOI: 10.1016/0141-0229(91)90068-l] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Robinson JA. Chemical and biochemical aspects of polyether-ionophore antibiotic biosynthesis. FORTSCHRITTE DER CHEMIE ORGANISCHER NATURSTOFFE = PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS. PROGRES DANS LA CHIMIE DES SUBSTANCES ORGANIQUES NATURELLES 1991; 58:1-81. [PMID: 1778521 DOI: 10.1007/978-3-7091-9141-5_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J A Robinson
- Organisch-Chemisches Institut, Universität Zürich, Switzerland
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Affiliation(s)
- S J Wakil
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030
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Huang WY, Stoops JK, Wakil SJ. Complete amino acid sequence of chicken liver acyl carrier protein derived from the fatty acid synthase. Arch Biochem Biophys 1989; 270:92-8. [PMID: 2648999 DOI: 10.1016/0003-9861(89)90011-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The acyl carrier protein domain of the chicken liver fatty acid synthase has been isolated after tryptic treatment of the synthase. The isolated domain functions as an acceptor of acetyl and malonyl moieties in the synthase-catalyzed transfer of these groups from their coenzyme A esters and therefore indicates that the acyl carrier protein domain exists in the complex as a discrete entity. The amino acid sequence of the acyl carrier protein was derived from analyses of peptide fragments produced by cyanogen bromide cleavage and trypsin and Staphylococcus aureus V8 protease digestions of the molecule. The isolated acyl carrier protein domain consists of 89 amino acid residues and has a calculated molecular weight of 10,127. The protein contains the phosphopantetheine group attached to the serine residue at position 38. The isolated acyl carrier protein peptide shows some sequence homology with the acyl carrier protein of Escherichia coli, particularly in the vicinity of the site of phosphopantetheine attachment, and shows extensive sequence homology with the acyl carrier protein from the uropygial gland of goose.
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Affiliation(s)
- W Y Huang
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030
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19
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Isolation and mapping of the beta-hydroxyacyl dehydratase activity of chicken liver fatty acid synthase. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37582-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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20
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Wiesner P, Beck J, Beck KF, Ripka S, Müller G, Lücke S, Schweizer E. Isolation and sequence analysis of the fatty acid synthetase FAS2 gene from Penicillium patulum. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 177:69-79. [PMID: 3053172 DOI: 10.1111/j.1432-1033.1988.tb14346.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The fatty acid synthetase complex of Penicillium patulum was isolated and shown to be structurally similar to other known fungal fatty acid synthetases. It is composed of two subunit, alpha and beta, each with a molecular mass of about 200 kDa. P. patulum genomic and cDNA libraries were constructed in lambda gt11 and EMBL3 vectors. From these libraries, the P. patulum FAS2 gene together with its flanking DNA was isolated. The cloned genomic DNA was sequenced over a length of 6357 base pairs. The coding sequence of fatty acid synthetase subunit alpha, being 5571 nucleotides long, was identified within this DNA segment. The FAS2 gene is a mosaic of three exons (514, 4949 and 108 base pairs) and two introns, each of 54 base pairs in length. Both introns were absent in the corresponding cDNA sequences. Like other fungal introns both contain an internal CTAAC sequence, located 10 base pairs upstream of their 3'-exon/intron boundaries. In addition, they have, at their ends, the GTCAAGT and TAG consensus sequences characteristic of all eucaryotic introns. Furthermore, two pairs of direct repeats, of as yet unknown significance, were found in the two P. patulum introns. The P. patulum FAS2 gene encodes a protein of 1857 amino acids and 204.5 kDa molecular mass. It is 90 nucleotides shorter than the corresponding S. cerevisiae gene. In both organisms, the FAS2 genes and their products exhibit a high degree of overall sequence similarity at both the DNA (63%) and protein (68%) levels. Therefore, the fatty acid synthetase alpha subunits of P. patulum and S. cerevisiae obviously contain the same catalytic domains in an identical sequential order.
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Affiliation(s)
- P Wiesner
- Lehrstuhl für Biochemie, Universität Erlangen-Nürnberg, Federal Republic of Germany
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21
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Kitamoto T, Nishigai M, Sasaki T, Ikai A. Structure of fatty acid synthetase from the Harderian gland of guinea pig. Proteolytic dissection and electron microscopic studies. J Mol Biol 1988; 203:183-95. [PMID: 3184185 DOI: 10.1016/0022-2836(88)90101-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Limited proteolysis and electron microscopic observation of fatty acid synthetase from the Harderian gland of guinea pig was performed to elucidate the higher-order structures of this multifunctional protein. Staphylococcus aureus V8 protease dissected the 250,000 Mr subunit of fatty acid synthetase into 120,000, 70,000, 35,000 and 30,000 Mr fragments, which were aligned in this order from the NH2 terminus. Some of the protease-resistant fragments produced with elastase, trypsin and lysyl endopeptidase were purified and fragment-specific antibodies (A40L, A33E and A25T) were prepared. A25T and A33F specifically bound the 35,000 and 30,000 Mr fragments, and A40L recognized the region between the 120,000 and 70,000 Mr fragments. Electron microscopic studies employing rotary shadowing, unidirectional shadowing and negative staining revealed that the overall dimension of the enzyme was 22 nm x 15 nm x 7 nm, and that two elongated subunits mainly composed of three subregions were in contact with each other at a few, three at most, points with two holes between them. The outer two attachment sites were often not in contact, indicating a certain flexibility of subunits at their ends. Immunocomplexes composed of fatty acid synthetase and fragment-specific antibodies were isolated and observed under the electron microscope. The attachment sites of A40L and A33E were located at the end of the minor and the major axes of the ellipsoidal contour of the molecule, respectively. Based on these results, the three-dimensional structure of animal fatty acid synthetase is discussed.
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Affiliation(s)
- T Kitamoto
- Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan
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22
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Small-angle neutron-scattering and electron microscope studies of the chicken liver fatty acid synthase. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61104-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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23
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Wakil SJ. The relationship between structure and function for and the regulation of the enzymes of fatty acid synthesis. Ann N Y Acad Sci 1986; 478:203-19. [PMID: 2879500 DOI: 10.1111/j.1749-6632.1986.tb15532.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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24
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Walters DW, Gilbert HF. Thiol/disulfide redox equilibrium and kinetic behavior of chicken liver fatty acid synthase. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)69281-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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25
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Hardie DG, Dewart KB, Aitken A, McCarthy AD. Amino acid sequence around the reactive serine residue of the thioesterase domain of rabbit fatty acid synthase. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 828:380-2. [PMID: 3921056 DOI: 10.1016/0167-4838(85)90320-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two thermolytic peptides containing the reactive serine residue of the thioesterase domain of rabbit fatty acid synthase have been isolated and sequenched by Edman degradation and fast atom bombardment mass spectrometry. The sequence (V-A-G-Y-S-Y-G) contains the motif G-X-S-X-G found around the reactive serine residue of all known serine proteinases and esterases.
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26
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Hammes GG. Fatty acid synthase: elementary steps in catalysis and regulation. CURRENT TOPICS IN CELLULAR REGULATION 1985; 26:311-24. [PMID: 4075824 DOI: 10.1016/b978-0-12-152826-3.50030-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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27
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Mattick JS, Tsukamoto Y, Nickless J, Wakil SJ. The architecture of the animal fatty acid synthetase. I. Proteolytic dissection and peptide mapping. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43805-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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28
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Tsukamoto Y, Wong H, Mattick JS, Wakil SJ. The architecture of the animal fatty acid synthetase complex. IV. Mapping of active centers and model for the mechanism of action. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43808-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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29
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Mattick JS, Nickless J, Mizugaki M, Yang CY, Uchiyama S, Wakil SJ. The architecture of the animal fatty acid synthetase. II. Separation of the core and thioesterase functions and determination of the N-C orientation of the subunit. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43806-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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