1
|
Lu H, Wang Z, Cao B, Cong F, Wang X, Wei W. Dietary sources of branched-chain fatty acids and their biosynthesis, distribution, and nutritional properties. Food Chem 2024; 431:137158. [PMID: 37604010 DOI: 10.1016/j.foodchem.2023.137158] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 08/05/2023] [Accepted: 08/13/2023] [Indexed: 08/23/2023]
Abstract
Branched-chain fatty acids (BCFAs) consist of a wide variety of fatty acids with alkyl branching of methyl group. The most common BCFAs are the types with one methyl group (mmBCFA) on the penultimate carbon (iBCFA) or the antepenultimate carbon (aiBCFA). Long-chain mmBCFAs are widely existing in animal fats, milks and are mostly derived from bacteria in the diet or animal digestive system. Recent studies show that BCFAs benefit human intestinal health and immune homeostasis, but the connection between their content, distribution in the human and their nutritional functions are not well established. In this paper, we reviewed BCFAs from various dietary sources focused on their molecular species. The BCFAs biosynthesis in bacteria, Caenorhabditis elegans, mammals and their distribution in human tissues are summarized. This paper also discusses the nutritional properties of BCFAs including influences on intestinal health, immunoregulatory effects, anti-carcinoma, and anti-obesity activities, by highlighting the most recent research progress.
Collapse
Affiliation(s)
- Huijia Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Zhen Wang
- Wilmar (Shanghai) Biotechnology Research & Development Center, Shanghai 200137, China; School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen 518107, China
| | - Bo Cao
- Wilmar (Shanghai) Biotechnology Research & Development Center, Shanghai 200137, China
| | - Fang Cong
- Wilmar (Shanghai) Biotechnology Research & Development Center, Shanghai 200137, China.
| | - Xingguo Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wei Wei
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| |
Collapse
|
2
|
Braesel J, Lee JH, Arnould B, Murphy BT, Eustáquio AS. Diazaquinomycin Biosynthetic Gene Clusters from Marine and Freshwater Actinomycetes. JOURNAL OF NATURAL PRODUCTS 2019; 82:937-946. [PMID: 30896942 PMCID: PMC6902439 DOI: 10.1021/acs.jnatprod.8b01028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Tuberculosis is an infectious disease of global concern. Members of the diazaquinomycin (DAQ) class of natural products have shown potent and selective activity against drug-resistant Mycobacterium tuberculosis. However, poor solubility has prevented further development of this compound class. Understanding DAQ biosynthesis may provide a viable route for the generation of derivatives with improved properties. We have sequenced the genomes of two actinomycete bacteria that produce distinct DAQ derivatives. While software tools for automated biosynthetic gene cluster (BGC) prediction failed to detect DAQ BGCs, comparative genomics using MAUVE alignment led to the identification of putative BGCs in the marine Streptomyces sp. F001 and in the freshwater Micromonospora sp. B006. Deletion of the identified daq BGC in strain B006 using CRISPR-Cas9 genome editing abolished DAQ production, providing experimental evidence for BGC assignment. A complete model for DAQ biosynthesis is proposed based on the genes identified. Insufficient knowledge of natural product biosynthesis is one of the major challenges of productive genome mining approaches. The results reported here fill a gap in knowledge regarding the genetic basis for the biosynthesis of DAQ antibiotics. Moreover, identification of the daq BGC shall enable future generations of improved derivatives using biosynthetic methods.
Collapse
Affiliation(s)
- Jana Braesel
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jung-Ho Lee
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Benoit Arnould
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Brian T. Murphy
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alessandra S. Eustáquio
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| |
Collapse
|
3
|
Genome-Wide Mutagenesis Links Multiple Metabolic Pathways with Actinorhodin Production in Streptomyces coelicolor. Appl Environ Microbiol 2019; 85:AEM.03005-18. [PMID: 30709825 PMCID: PMC6585502 DOI: 10.1128/aem.03005-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/25/2019] [Indexed: 12/22/2022] Open
Abstract
Streptomyces species are important antibiotic-producing organisms that tightly regulate their antibiotic production. Actinorhodin is a typical antibiotic produced by the model actinomycete Streptomyces coelicolor To discover the regulators of actinorhodin production, we constructed a library of 50,000 independent mutants with hyperactive Tn5 transposase-based transposition systems. Five hundred fifty-one genes were found to influence actinorhodin production in 988 individual mutants. Genetic complementation suggested that most of the insertions (76%) were responsible for the changes in antibiotic production. Genes involved in diverse cellular processes such as amino acid biosynthesis, carbohydrate metabolism, cell wall homeostasis, and DNA metabolism affected actinorhodin production. Genome-wide mutagenesis can identify novel genes and pathways that impact antibiotic levels, potentially aiding in engineering strains to optimize the production of antibiotics in Streptomyces IMPORTANCE Previous studies have shown that various genes can influence antibiotic production in Streptomyces and that intercommunication between regulators can complicate antibiotic production. Therefore, to gain a better understanding of antibiotic regulation, a genome-wide perspective on genes that influence antibiotic production was needed. We searched for genes that affected production of the antibiotic actinorhodin using a genome-wide gene disruption system. We identified 551 genes that altered actinorhodin levels, and more than half of these genes were newly identified effectors. Some of these genes may be candidates for engineering Streptomyces strains to improve antibiotic production levels.
Collapse
|
4
|
Yi JS, Kim M, Kim EJ, Kim BG. Production of pikromycin using branched chain amino acid catabolism in Streptomyces venezuelae ATCC 15439. J Ind Microbiol Biotechnol 2018. [PMID: 29523997 DOI: 10.1007/s10295-018-2024-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Branched chain amino acids (BCAA) are catabolized into various acyl-CoA compounds, which are key precursors used in polyketide productions. Because of that, BCAA catabolism needs fine tuning of flux balances for enhancing the production of polyketide antibiotics. To enhance BCAA catabolism for pikromycin production in Streptomyces venezuelae ATCC 15439, three key enzymes of BCAA catabolism, 3-ketoacyl acyl carrier protein synthase III, acyl-CoA dehydrogenase, and branched chain α-keto acid dehydrogenase (BCDH) were manipulated. BCDH overexpression in the wild type strain resulted in 1.3 fold increase in pikromycin production compared to that of WT, resulting in total 25 mg/L of pikromycin. To further increase pikromycin production, methylmalonyl-CoA mutase linked to succinyl-CoA production was overexpressed along with BCDH. Overexpression of the two enzymes resulted in the highest titer of total macrolide production of 43 mg/L, which was about 2.2 fold increase compared to that of the WT. However, it accumulated and produced dehydroxylated forms of pikromycin and methymycin, including their derivatives as well. It indicated that activities of pikC, P450 monooxygenase, newly became a bottleneck in pikromycin synthesis.
Collapse
Affiliation(s)
- Jeong Sang Yi
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Minsuk Kim
- Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun-Jung Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea. .,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea. .,Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea. .,Interdisciplinary Program for Biochemical Engineering and Biotechnology, and Bioengineering Institute, Seoul National University, Seoul, 08826, Republic of Korea.
| |
Collapse
|
5
|
Röttig A, Strittmatter CS, Schauer J, Hiessl S, Poehlein A, Daniel R, Steinbüchel A. Role of Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase in Oleaginous Streptomyces sp. Strain G25. Appl Environ Microbiol 2016; 82:5969-81. [PMID: 27474711 PMCID: PMC5038041 DOI: 10.1128/aem.01719-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/20/2016] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED Recently, we isolated a novel Streptomyces strain which can accumulate extraordinarily large amounts of triacylglycerol (TAG) and consists of 64% fatty acids (dry weight) when cultivated with glucose and 50% fatty acids (dry weight) when cultivated with cellobiose. To identify putative gene products responsible for lipid storage and cellobiose utilization, we analyzed its draft genome sequence. A single gene encoding a wax ester synthase/acyl coenzyme A (CoA):diacylglycerol acyltransferase (WS/DGAT) was identified and heterologously expressed in Escherichia coli The purified enzyme AtfG25 showed acyltransferase activity with C12- or C16-acyl-CoA, C12 to C18 alcohols, or dipalmitoyl glycerol. This acyltransferase exhibits 24% amino acid identity to the model enzyme AtfA from Acinetobacter baylyi but has high sequence similarities to WS/DGATs from other Streptomyces species. To investigate the impact of AtfG25 on lipid accumulation, the respective gene, atfG25, was inactivated in Streptomyces sp. strain G25. However, cells of the insertion mutant still exhibited DGAT activity and were able to store TAG, albeit in lower quantities and at lower rates than the wild-type strain. These findings clearly indicate that AtfG25 has an important, but not exclusive, role in TAG biosynthesis in the novel Streptomyces isolate and suggest the presence of alternative metabolic pathways for lipid accumulation which are discussed in the present study. IMPORTANCE A novel Streptomyces strain was isolated from desert soil, which represents an extreme environment with high temperatures, frequent drought, and nutrient scarcity. We believe that these harsh conditions promoted the development of the capacity for this strain to accumulate extraordinarily large amounts of lipids. In this study, we present the analysis of its draft genome sequence with a special focus on enzymes potentially involved in its lipid storage. Furthermore, the activity and importance of the detected acyltransferase were studied. As discussed in this paper, and in contrast to many other bacteria, streptomycetes seem to possess a complex metabolic network to synthesize lipids, whereof crucial steps are still largely unknown. This paper therefore provides insights into a range of topics, including extremophile bacteria, the physiology of lipid accumulation, and the biotechnological production of bacterial lipids.
Collapse
Affiliation(s)
- Annika Röttig
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Carl Simon Strittmatter
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Jennifer Schauer
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Sebastian Hiessl
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Göttingen, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany Faculty of Environmental Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| |
Collapse
|
6
|
Cabruja M, Lyonnet BB, Millán G, Gramajo H, Gago G. Analysis of coenzyme A activated compounds in actinomycetes. Appl Microbiol Biotechnol 2016; 100:7239-48. [PMID: 27270600 DOI: 10.1007/s00253-016-7635-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/06/2016] [Accepted: 05/14/2016] [Indexed: 10/21/2022]
Abstract
Acyl-CoAs are crucial compounds involved in essential metabolic pathways such as the Krebs cycle and lipid, carbohydrate, and amino acid metabolisms, and they are also key signal molecules involved in the transcriptional regulation of lipid biosynthesis in many organisms. In this study, we took advantage of the high selectivity of mass spectrometry and developed an ion-pairing reverse-phase high-pressure liquid chromatography electrospray ionization high-resolution mass spectrometry (IP-RP-HPLC/ESI-HRMS) method to carry on a comprehensive analytical determination of the wide range of fatty acyl-CoAs present in actinomycetes. The advantage of using a QTOF spectrometer resides in the excellent mass accuracy over a wide dynamic range and measurements of the true isotope pattern that can be used for molecular formula elucidation of unknown analytes. As a proof of concept, we used this assay to determine the composition of the fatty acyl-CoA pools in Mycobacterium, Streptomyces, and Corynebacterium species, revealing an extraordinary difference in fatty acyl-CoA amounts and species distribution between the three genera and between the two species of mycobacteria analyzed, including the presence of different chain-length carboxy-acyl-CoAs, key substrates of mycolic acid biosynthesis. The method was also used to analyze the impact of two fatty acid synthase inhibitors on the acyl-CoA profile of Mycobacterium smegmatis, which showed some unexpected low levels of C24 acyl-CoAs in the isoniazid-treated cells. This robust, sensitive, and reliable method should be broadly applicable in the studies of the wide range of bacteria metabolisms in which acyl-CoA molecules participate.
Collapse
Affiliation(s)
- Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina
| | - Bernardo Bazet Lyonnet
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina
| | - Gustavo Millán
- Laboratory of Mass Spectrometry, Centro Científico Tecnológico Rosario, CONICET, Rosario, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina.
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina.
| |
Collapse
|
7
|
Escudero L, Al-Refai M, Nieto C, Laatsch H, Malpartida F, Seco EM. New Rimocidin/CE-108 Derivatives Obtained by a Crotonyl-CoA Carboxylase/Reductase Gene Disruption in Streptomyces diastaticus var. 108: Substrates for the Polyene Carboxamide Synthase PcsA. PLoS One 2015; 10:e0135891. [PMID: 26284936 PMCID: PMC4540446 DOI: 10.1371/journal.pone.0135891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/27/2015] [Indexed: 11/19/2022] Open
Abstract
The rimJ gene, which codes for a crotonyl-CoA carboxylase/reductase, lies within the biosynthetic gene cluster for two polyketides belonging to the polyene macrolide group (CE-108 and rimocidin) produced by Streptomyces diastaticus var. 108. Disruption of rimJ by insertional inactivation gave rise to a recombinant strain overproducing new polyene derivatives besides the parental CE-108 (2a) and rimocidin (4a). The structure elucidation of one of them, CE-108D (3a), confirmed the incorporation of an alternative extender unit for elongation step 13. Other compounds were also overproduced in the fermentation broth of rimJ disruptant. The new compounds are in vivo substrates for the previously described polyene carboxamide synthase PcsA. The rimJ disruptant strain, constitutively expressing the pcsA gene, allowed the overproduction of CE-108E (3b), the corresponding carboxamide derivative of CE-108D (3a), with improved pharmacological properties.
Collapse
Affiliation(s)
- Leticia Escudero
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Mahmoud Al-Refai
- Department of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077, Göttingen, Germany
| | - Cristina Nieto
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Hartmut Laatsch
- Department of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077, Göttingen, Germany
| | - Francisco Malpartida
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Elena M. Seco
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
- * E-mail:
| |
Collapse
|
8
|
Wu H, San KY. Efficient odd straight medium chain free fatty acid production by metabolically engineered Escherichia coli. Biotechnol Bioeng 2014; 111:2209-19. [PMID: 24889416 DOI: 10.1002/bit.25296] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/24/2014] [Accepted: 05/25/2014] [Indexed: 11/11/2022]
Abstract
Free fatty acids (FFAs) can be used as precursors for the production of biofuels or chemicals. Different composition of FFAs will be useful for further modification of the biofuel/biochemical quality. Microbial biosynthesis of even chain FFAs can be achieved by introducing an acyl-acyl carrier protein thioesterase gene into E. coli. In this study, odd straight medium chain FFAs production was investigated by using metabolic engineered E. coli carrying acyl-ACP thioesterase (TE, Ricinus communis), propionyl-CoA synthase (Salmonella enterica), and β-ketoacyl-acyl carrier protein synthase III (four different sources) with supplement of extracellular propionate. By using these metabolically engineered E. coli, significant quantity of C13 and C15 odd straight-chain FFAs could be produced from glucose and propionate. The highest concentration of total odd straight chain FFAs attained was 1205 mg/L by the strain HWK201 (pXZ18, pBHE2), and 85% of the odd straight chain FFAs was C15. However, the highest percentage of odd straight chain FFAs was achieved by the strain HWK201 (pXZ18, pBHE3) of 83.2% at 48 h. This strategy was also applied successfully in strains carrying different TE, such as the medium length acyl-ACP thioesterase gene from Umbellularia californica. C11 and C13 became the major odd straight-chain FFAs.
Collapse
Affiliation(s)
- Hui Wu
- Department of Bioengineering, Rice University, Houston, Texas
| | | |
Collapse
|
9
|
Sidebottom AM, Johnson AR, Karty JA, Trader DJ, Carlson EE. Integrated metabolomics approach facilitates discovery of an unpredicted natural product suite from Streptomyces coelicolor M145. ACS Chem Biol 2013; 8:2009-16. [PMID: 23777274 DOI: 10.1021/cb4002798] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Natural products exhibit a broad range of biological properties and have been a crucial source of therapeutic agents and novel scaffolds. Although bacterial secondary metabolomes are widely explored, they remain incompletely cataloged by current isolation and characterization strategies. To identify metabolites residing in unexplored chemical space, we have developed an integrated discovery approach that combines bacterial growth perturbation, accurate mass spectrometry, comparative mass spectra data analysis, and fragmentation spectra clustering for the identification of low-abundant, novel compounds from complex biological matrices. In this investigation, we analyzed the secreted metabolome of the extensively studied Actinomycete, Streptomyces coelicolor M145, and discovered a low-abundant suite of 15 trihydroxamate, amphiphilic siderophores. Compounds in this class have primarily been observed in marine microorganisms making their detection in the soil-dwelling S. coelicolor M145 significant. At least 10 of these ferrioxamine-based molecules are not known to be produced by any organism, and none have previously been detected from S. coelicolor M145. In addition, we confirmed the production of ferrioxamine D1, a relatively hydrophilic family member that has not been shown to be biosynthesized by this organism. The identified molecules are part of only a small list of secondary metabolites that have been discovered since sequencing of S. coelicolor M145 revealed that it possessed numerous putative secondary metabolite-producing gene clusters with no known metabolites. Thus, the identified siderophores represent the unexplored metabolic potential of both well-studied and new organisms that could be uncovered with our sensitive and robust approach.
Collapse
Affiliation(s)
- Ashley M. Sidebottom
- Department of Chemistry and ‡Department of Molecular
and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Andrew R. Johnson
- Department of Chemistry and ‡Department of Molecular
and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Jonathan A. Karty
- Department of Chemistry and ‡Department of Molecular
and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Darci J. Trader
- Department of Chemistry and ‡Department of Molecular
and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Erin E. Carlson
- Department of Chemistry and ‡Department of Molecular
and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| |
Collapse
|
10
|
|
11
|
Wilson MC, Moore BS. Beyond ethylmalonyl-CoA: the functional role of crotonyl-CoA carboxylase/reductase homologs in expanding polyketide diversity. Nat Prod Rep 2011; 29:72-86. [PMID: 22124767 DOI: 10.1039/c1np00082a] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review covers the emerging biosynthetic role of crotonyl-CoA carboxylase/reductase (CCR) homologs in extending the structural and functional diversity of polyketide natural products. CCRs catalyze the reductive carboxylation of α,β-unsaturated acyl-CoA substrates to produce a variety of substituted malonyl-CoA derivatives employed as polyketide synthase extender units. Here we discuss the history of CCRs in both primary and secondary metabolism, the mechanism by which they function, examples of new polyketide diversity from pathway specific CCRs, and the role of CCRs in facilitating the bioengineering novel polyketides.
Collapse
Affiliation(s)
- Micheal C Wilson
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, USA
| | | |
Collapse
|
12
|
Gago G, Diacovich L, Arabolaza A, Tsai SC, Gramajo H. Fatty acid biosynthesis in actinomycetes. FEMS Microbiol Rev 2011; 35:475-97. [PMID: 21204864 DOI: 10.1111/j.1574-6976.2010.00259.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation for elucidating the type II FAS pathways in other bacteria (White et al., 2005). However, fatty acid biosynthesis is more diverse in the phylum Actinobacteria: Mycobacterium, possess both FAS systems while Streptomyces species have only the multienzyme FAS II system and Corynebacterium species exclusively FAS I. In this review, we present an overview of the genome organization, biochemical properties and physiological relevance of the two FAS systems in the three genera of actinomycetes mentioned above. We also address in detail the biochemical and structural properties of the acyl-CoA carboxylases (ACCases) that catalyzes the first committed step of fatty acid synthesis in actinomycetes, and discuss the molecular bases of their substrate specificity and the structure-based identification of new ACCase inhibitors with antimycobacterial properties.
Collapse
Affiliation(s)
- Gabriela Gago
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | | | | | | | | |
Collapse
|
13
|
Arabolaza A, D'Angelo M, Comba S, Gramajo H. FasR, a novel class of transcriptional regulator, governs the activation of fatty acid biosynthesis genes in Streptomyces coelicolor. Mol Microbiol 2010; 78:47-63. [PMID: 20624224 DOI: 10.1111/j.1365-2958.2010.07274.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane lipid homeostasis is essential for bacterial survival and adaptation to different environments. The regulation of fatty acid biosynthesis is therefore crucial for maintaining the correct composition and biophysical properties of cell membranes. This regulation implicates a biochemical control of key enzymes and a transcriptional regulation of genes involved in lipid metabolism. In Streptomyces coelicolor we found that control of lipid homeostasis is accomplished, at least in part, through the transcriptional regulation of fatty acid biosynthetic genes. A novel transcription factor, FasR (SCO2386), controls expression of fabDHPF operon and lies immediately upstream of fabD, in a cluster of genes that is highly conserved within actinomycetes. Disruption of fasR resulted in a mutant strain, with severe growth defects and a delay in the timing of morphological and physiological differentiation. Expression of fab genes was downregulated in the fasR mutant, indicating a role for this transcription factor as an activator. Consequently, the mutant showed a significant drop in fatty acid synthase activity and triacylglyceride accumulation. FasR binds specifically to a DNA sequence containing fabDHPF promoter region, both in vivo and in vitro. These data provide the first example of positive regulation of genes encoding core proteins of saturated fatty acid synthase complex.
Collapse
Affiliation(s)
- Ana Arabolaza
- Microbiology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (S2002LRK) Rosario, Argentina
| | | | | | | |
Collapse
|
14
|
Cronan JE, Thomas J. Bacterial fatty acid synthesis and its relationships with polyketide synthetic pathways. Methods Enzymol 2009; 459:395-433. [PMID: 19362649 DOI: 10.1016/s0076-6879(09)04617-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
This review presents the most thoroughly studied bacterial fatty acid synthetic pathway, that of Escherichia coli and then discusses the exceptions to the E. coli pathway present in other bacteria. The known interrelationships between the fatty acid and polyketide synthetic pathways are also assessed, mainly in the Streptomyces group of bacteria. Finally, we present a compendium of methods for analysis of bacterial fatty acid synthetic pathways.
Collapse
Affiliation(s)
- John E Cronan
- Department of Biochemistry, University of Illinois, Urbana, Illinois, USA
| | | |
Collapse
|
15
|
Branched-chain amino acid catabolism provides precursors for the Type II polyketide antibiotic, actinorhodin, via pathways that are nutrient dependent. J Ind Microbiol Biotechnol 2008; 36:129-37. [DOI: 10.1007/s10295-008-0480-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 09/17/2008] [Indexed: 10/21/2022]
|
16
|
Jovetic S, Feroggio M, Marinelli F, Lancini G. Factors influencing cell fatty acid composition and A40926 antibiotic complex production in Nonomuraea sp. ATCC 39727. J Ind Microbiol Biotechnol 2008; 35:1131-8. [DOI: 10.1007/s10295-008-0392-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 07/02/2008] [Indexed: 11/30/2022]
|
17
|
Funabashi M, Funa N, Horinouchi S. Phenolic lipids synthesized by type III polyketide synthase confer penicillin resistance on Streptomyces griseus. J Biol Chem 2008; 283:13983-91. [PMID: 18364359 DOI: 10.1074/jbc.m710461200] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type III polyketide synthases (PKSs) found in plants, fungi, and bacteria synthesize a variety of aromatic polyketides. A Gram-positive, filamentous bacterium Streptomyces griseus contained an srs operon, in which srsA encoded a type III PKS, srsB encoded a methyltransferase, and srsC encoded a flavoprotein hydroxylase. Consistent with this annotation, overexpression of the srs genes in a heterologous host, Streptomyces lividans, showed that SrsA was a type III PKS responsible for synthesis of phenolic lipids, alkylresorcinols, and alkylpyrones, SrsB was a methyltransferase acting on the phenolic lipids to yield alkylresorcinol methyl ethers, and SrsC was a hydroxylase acting on the alkylresorcinol methyl ethers. In vitro SrsA reaction showed that SrsA synthesized alkylresorcinols from acyl-CoAs of various chain lengths as a starter substrate, one molecule of methylmalonyl-CoA, and two molecules of malonyl-CoA. SrsA was thus unique in that it incorporated the extender substrates in a strictly controlled order of malonyl-CoA, malonyl-CoA, and methylmalonyl-CoA to produce alkylresorcinols. An srsA mutant, which produced no phenolic lipids, was highly sensitive to beta-lactam antibiotics, such as penicillin G and cephalexin. Together with the fact that the alkylresorcinols were fractionated mainly in the cell wall fraction, this observation suggests that the phenolic lipids, perhaps associated with the cytoplasmic membrane because of their amphiphilic property, affect the characteristic and rigidity of the cytoplasmic membrane/peptidoglycan of a variety of bacteria. An srs-like operon is found widely among Gram-positive and -negative bacteria, indicating wide distribution of the phenolic lipids.
Collapse
Affiliation(s)
- Masanori Funabashi
- Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo,Tokyo 113-8657, Japan
| | | | | |
Collapse
|
18
|
Xu Z, Schenk A, Hertweck C. Molecular analysis of the benastatin biosynthetic pathway and genetic engineering of altered fatty acid-polyketide hybrids. J Am Chem Soc 2007; 129:6022-30. [PMID: 17439117 DOI: 10.1021/ja069045b] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The entire gene locus encoding the biosynthesis of the potent glutathione-S-transferase inhibitors and apoptosis inducers benastatin A and B has been cloned and sequenced. The cluster identity was unequivocally proven by deletion of flanking regions and heterologous expression in S. albus and S. lividans. Inactivation and complementation experiments revealed that a KSIII component (BenQ) similar to FabH is crucial for providing and selecting the rare hexanoate PKS starter unit. In the absence of BenQ, several novel penta- and hexacyclic benastatin derivatives with antiproliferative activities are formed. In total, five new compounds were isolated and fully characterized, and the chemical analysis was confirmed by derivatization. The most intriguing observation is that the ben PKS can utilize typical straight and branched fatty acid synthase primers. If shorter straight-chain starters are utilized, the length of the polyketide backbone is increased, resulting in the formation of an extended, hexacyclic ring system reminiscent of proposed intermediates in the griseorhodin and fredericamycin pathways. Analysis and manipulation of the hybrid fatty acid polyketide pathway provides strong support for the hypothesis that the number of chain elongations is dependent on the total size of the polyketide chain that is accommodated in the PKS enzyme cavity. Our results also further substantiate the potential of metabolic engineering toward polyphenols with altered substituents and ring systems.
Collapse
Affiliation(s)
- Zhongli Xu
- Leibniz Institute for Natural Product Research and Infection Biology, HKI, Department of Biomolecular Chemistry, Beutenbergstrasse 11a, 07745 Jena, Germany
| | | | | |
Collapse
|
19
|
Kato JY, Funa N, Watanabe H, Ohnishi Y, Horinouchi S. Biosynthesis of gamma-butyrolactone autoregulators that switch on secondary metabolism and morphological development in Streptomyces. Proc Natl Acad Sci U S A 2007; 104:2378-83. [PMID: 17277085 PMCID: PMC1892969 DOI: 10.1073/pnas.0607472104] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) is a representative of the gamma-butyrolactone autoregulators that trigger secondary metabolism and morphogenesis in the Gram-positive, filamentous bacterial genus Streptomyces. Here, we report the A factor biosynthesis pathway in Streptomyces griseus. The monomeric AfsA, containing a tandem repeat domain of approximately 80 aa, catalyzed beta-ketoacyl transfer from 8-methyl-3-oxononanoyl-acyl carrier protein to the hydroxyl group of dihydroxyacetone phosphate (DHAP), thus producing an 8-methyl-3-oxononanoyl-DHAP ester. The fatty acid ester was nonenzymatically converted to a butenolide phosphate by intramolecular aldol condensation. The butenolide phosphate was then reduced by BprA that was encoded just downstream of afsA. The phosphate group on the resultant butanolide was finally removed by a phosphatase, resulting in formation of A factor. The 8-methyl-3-oxononanoyl-DHAP ester produced by the action of AfsA was also converted to A factor in an alternative way; the phosphate group on the ester was first removed by a phosphatase and the dephosphorylated ester was converted nonenzymatically to a butenolide, which was then reduced by a reductase different from BprA, resulting in A factor. Because introduction of afsA alone into Escherichia coli caused the host to produce a substance having A factor activity, the reductase(s) and phosphatase(s) were not specific to the A factor biosynthesis but commonly present in bacteria. AfsA is thus the key enzyme for the biosynthesis of gamma-butyrolactones.
Collapse
Affiliation(s)
| | | | - Hidenori Watanabe
- Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Sueharu Horinouchi
- Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
20
|
Parry RJ. New prodiginines from a ketosynthase swap. ACTA ACUST UNITED AC 2005; 12:145-6. [PMID: 15734641 DOI: 10.1016/j.chembiol.2005.01.007] [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: 11/17/2022]
Abstract
The prodiginine antibiotics exhibit antitumor and immunosuppressive activity. In this issue of Chemistry & Biology, Reynolds and coworkers demonstrate that new prodiginines can be obtained by substituting a FabH ketosynthase for the RedP ketosynthase in the undecylprodiginine biosynthetic gene cluster.
Collapse
Affiliation(s)
- Ronald J Parry
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| |
Collapse
|
21
|
Brunati M, Bava A, Marinelli F, Lancini G. Influence of Leucine and Valine on Ramoplanin Production by Actinoplanes sp. ATCC 33076. J Antibiot (Tokyo) 2005; 58:473-8. [PMID: 16161487 DOI: 10.1038/ja.2005.63] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ramoplanin is a glycolipodepsipeptide antibiotic obtained by fermentation of the Actinoplanes sp. ATCC 33076, isolated as a complex of three closely related components A1, A2 and A3, which differ in their fatty acid moiety. We have investigated the influence of L-leucine and L-valine, the biosynthetic precursors of the fatty acids in A2 and A3 factors, on the complex composition and antibiotic productivity. Addition of 5 g/litre of L-leucine at the time of inoculation increases antibiotic production and improves the production of A2 factor, which represents the active principle component under clinical development. Addition of L-valine in the same conditions modifies the composition of the complex towards the A3 factor but does not improve total antibiotic productivity. A possible explanation for the different actions of the two amino acids is presented.
Collapse
Affiliation(s)
- Mara Brunati
- Vicuron Pharmaceuticals, Via R Lepetit 34, 21040, Gerenzano, Varese, Italy.
| | | | | | | |
Collapse
|
22
|
Li Y, Florova G, Reynolds KA. Alteration of the fatty acid profile of Streptomyces coelicolor by replacement of the initiation enzyme 3-ketoacyl acyl carrier protein synthase III (FabH). J Bacteriol 2005; 187:3795-9. [PMID: 15901703 PMCID: PMC1112031 DOI: 10.1128/jb.187.11.3795-3799.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The first elongation step of fatty acid biosynthesis by a type II dissociated fatty acid synthases is catalyzed by 3-ketoacyl-acyl carrier protein (ACP) synthase III (KASIII, FabH). This enzyme, encoded by the fabH gene, catalyzes a decarboxylative condensation between an acyl coenzyme A (CoA) primer and malonyl-ACP. In organisms such as Escherichia coli, which generate only straight-chain fatty acids (SCFAs), FabH has a substrate preference for acetyl-CoA. In streptomycetes and other organisms which produce a mixture of both SCFAs and branched-chain fatty acids (BCFAs), FabH has been shown to utilize straight- and branched-chain acyl-CoA substrates. We report herein the generation of a Streptomyces coelicolor mutant (YL/ecFabH) in which the chromosomal copy of the fabH gene has been replaced and the essential process of fatty acid biosynthesis is initiated by plasmid-based expression of the E. coli FabH (bearing only 35% amino acid identity to the Streptomyces enzyme). The YL/ecFabH mutant produces predominantly SCFAs (86%). In contrast, BCFAs predominate (approximately 70%) in both the S. coelicolor parental strain and S. coelicolor YL/sgFabH (a deltafabH mutant carrying a plasmid expressing the Streptomyces glaucescens FabH). These results provide the first unequivocal evidence that the substrate specificity of FabH observed in vitro is a determinant of the fatty acid made in an organism. The YL/ecFabH strain grows significantly slower on both solid and liquid media. The levels of FabH activity in cell extracts of YL/ecFabH were also significantly lower than those in cell extracts of YL/sgFabH, suggesting that a decreased rate of fatty acid synthesis may account for the observed decreased growth rate. The production of low levels of BCFAs in YL/ecFabH suggests either that the E. coli FabH is more tolerant of different acyl-CoAs substrates than previously thought or that there is an additional pathway for initiation of BCFA biosynthesis in Streptomyces coelicolor.
Collapse
Affiliation(s)
- Yongli Li
- Department of Medicinal Chemistry and Institute of Structural Biology and Drug Discovery, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | |
Collapse
|
23
|
Beck HC. Branched-chain fatty acid biosynthesis in a branched-chain amino acid aminotransferase mutant of Staphylococcus carnosus. FEMS Microbiol Lett 2005; 243:37-44. [PMID: 15667998 DOI: 10.1016/j.femsle.2004.11.041] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Revised: 11/17/2004] [Accepted: 11/21/2004] [Indexed: 10/26/2022] Open
Abstract
Fatty acid biosynthesis by a mutant strain of Staphylococcus carnosus deficient in branched-chain amino acid aminotransferase (IlvE) activity was analysed. This mutant was unable to produce the appropriate branched-chain alpha-ketoacid precursors for branched-chain fatty acid biosynthesis from the amino acids valine, isoleucine, and leucine, and required the short branched chain acids 2-methylbutanoic acid or 2-methylpropanoic acid for growth in a defined medium. The isoleucine related metabolites, alpha-keto-beta-methylvaleric acid and 2-methylbutanal also served as growth factors. Growth in rich medium and growth in defined medium supplemented with 2-methylpropanoic acid lead to extensive alteration of the fatty acid composition in the cell membrane. In rich medium, a change from 51.7% to 17.1% anteiso-C15:0, and from 3.6% to 33.9% iso-C14:0 fatty acids as compared to the wild-type strain was observed. Despite the deficiency in IlvE activity, the mutant strain was still able to produce the short chain carboxylic acids, 3-methylbutanoic acid and 2-methylpropanoic acid when cultivated in rich medium. Supplementation experiments employing deuterated glucose induced the valine biosynthetic pathway for 2-methylpropanoic acid production, revealing that the IlvE protein plays an important, but not essential role in the biosynthesis of branched-chain fatty acids and secondary metabolites in S. carnosus.
Collapse
Affiliation(s)
- Hans C Beck
- Danish Technological Institute, Holbergsvej 10, DK-6000 Kolding, Denmark.
| |
Collapse
|
24
|
Mo S, Kim BS, Reynolds KA. Production of Branched-Chain Alkylprodiginines in S. coelicolor by Replacement of the 3-Ketoacyl ACP Synthase III Initiation Enzyme, RedP. ACTA ACUST UNITED AC 2005; 12:191-200. [PMID: 15734646 DOI: 10.1016/j.chembiol.2004.11.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 11/05/2004] [Accepted: 11/05/2004] [Indexed: 11/24/2022]
Abstract
The enzyme RedP is thought to initiate the biosynthesis of the undecylpyrolle component of the antibiotic undecylprodiginine produced by Streptomyces coelicolor. RedP has homology to FabH, which initiates fatty acid biosynthesis by condensing the appropriate acyl-CoA starter unit with malonyl ACP. We have generated a redP-deletion mutant of S. coelicolor M511 (SJM1) and shown that it produces reduced levels of prodiginines and two new analogs, methylundecylprodiginine and methyldodecylprodiginine. Incorporation studies with perdeuterated valine were consistent with these being generated using methylbutyryl-CoA and isobutyryl-CoA as starter units, respectively. Plasmid-based expression of a streptomycete fabH in the SJM1 mutant led to restoration of overall prodiginine titers but the same overall ratio of undecylprodiginines and novel prodiginines. Thus, the redP FabH can be replaced by FabH enzymes with different substrate specificities and provides a method for generating novel prodiginines.
Collapse
Affiliation(s)
- Sangjoon Mo
- Department of Medicinal Chemistry and, Institute of Structural Biology and Drug Discovery, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | |
Collapse
|
25
|
Dembitsky VM, Rezanka T, Srebnik M. Lipid compounds of freshwater sponges: family Spongillidae, class Demospongiae. Chem Phys Lipids 2003; 123:117-55. [PMID: 12691847 DOI: 10.1016/s0009-3084(03)00020-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
More than 100 novel, unusual and rare fatty acids, lipids and sterols have been isolated from freshwater sponges. The structures, biogenesis, synthesis and bioactivity of some lipid compounds of freshwater sponge species are reviewed.
Collapse
Affiliation(s)
- Valery M Dembitsky
- Department of Medicinal Chemistry and Natural Products, School of Pharmacy, P.O. Box 12065, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
| | | | | |
Collapse
|
26
|
|
27
|
Tsvetanova BC, Kiemle DJ, Price NPJ. Biosynthesis of tunicamycin and metabolic origin of the 11-carbon dialdose sugar, tunicamine. J Biol Chem 2002; 277:35289-96. [PMID: 12093793 DOI: 10.1074/jbc.m201345200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tunicamycin is a reversible inhibitor of polyprenol-phosphate: N-acetylhexosamine-1-phosphate translocases and is produced by several Streptomyces species. We have examined tunicamycin biosynthesis, an important but poorly characterized biosynthetic pathway. Biosynthetic precursors have been identified by incorporating radioactive and stable isotopes, and by determining the labeling pattern using electrospray ionization-collision induced dissociation-mass spectrometry (ESI-CID-MS), and proton, deuterium, and C-13 nuclear magnetic resonance (NMR) spectroscopy. Preparation and analysis of [uracil-5-(2)H]-labeled tunicamycin established the complete ESI-CID-MS fragmentation pathway for the major components of the tunicamycin complex. Competitive metabolic experiments indicate that 7 deuteriums incorporate into tunicamycin from [6,6'-(2)H,(2)H]-labeled D-glucose, 6 of which arise from D-GlcNAc and 1 from uridine and/or D-ribose. Inverse correlation NMR experiments (heteronuclear single-quantum coherence (HSQC)) of (13)C-labeled tunicamycin enriched from D-[1-(13)C]glucose suggest that the unique tunicamine 11-carbon dialdose sugar backbone arises from a 5-carbon furanose precursor derived from uridine and a 6-carbon N-acetylamino-pyranose precursor derived from UDP-D-N-acetylglucosamine. The equivalent incorporation of (13)C into both the alpha-1" and beta-11' anomeric carbons of tunicamycin supports a direct biosynthesis via 6-carbon metabolism. It also indicates that the tunicamine motif and the alpha-1"-linked GlcNAc residue are both derived from the same metabolic pool of UDP-GlcNAc, without significant differential metabolic processing. A biosynthetic pathway is therefore proposed for tunicamycin for the first time: an initial formation of the 11-carbon tunicamine sugar motif from uridine and UDP-GlcNAc via uridine-5'-aldehyde and UDP-4-keto-6-ene-N-acetylhexosamine, respectively, and subsequent formation of the anomeric-to-anomeric alpha, beta-1",11'-glycosidic bond.
Collapse
Affiliation(s)
- Billyana C Tsvetanova
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York 13210, USA
| | | | | |
Collapse
|
28
|
Kim BS, Cropp TA, Florova G, Lindsay Y, Sherman DH, Reynolds KA. An unexpected interaction between the modular polyketide synthases, erythromycin DEBS1 and pikromycin PikAIV, leads to efficient triketide lactone synthesis. Biochemistry 2002; 41:10827-33. [PMID: 12196022 DOI: 10.1021/bi0256779] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An unusual feature of the 6-module pikromycin polyketide synthase (PikPKS, PikAI-PikAIV) of S. venezuelae is the ability to generate both 12- and 14-membered ring macrolides. The PikAIV component containing the last extension module and a thioesterase domain is responsible for generating both of these products. In the case of the 12-membered ring macrolide, an acyl-enzyme intermediate on PikAIII is able to efficiently "skip" the last extension step and is cyclized by the TE domain of PikAIV, presumably as a result of a PikAIII-PikAIV interaction. Herein we report that plasmid-based expression (pBK3) of DEBS1, which comprises the loading domain and the first two modules of the Saccharopolyspora erythrea 6-deoxyerythronolide B synthase, in S. venezuelae leads to efficient 15 +/- 3 mg/L production of triketide lactone products (TKLs). Comparable levels of TKLs were observed with a plasmid (pBK1) which expressed DEBS1 fused to a TE domain (DEBS1-TE). These results are in stark contrast to previous in vivo and in vitro analyses, where only DEBS1-TE efficiently produces TKLs. Levels of TKLs decreased dramatically with expression of DEBS1 in both pikAIV and pikAIII-pikAIV deletion hosts (0.5 mg/L), but not DEBS1-TE, and could be partially restored by addition of a PikAIV complementation plasmid. These data suggest that PikAIV is able to efficiently catalyze formation of 6-membered lactone ring products from acyl-bound intermediates on DEBS1 in a manner analogous to that observed for 12-membered macrolide products from PikAIII. Significant sequence similarity and length of the C-terminal linker region of PikAIII and DEBS1 suggest that this region may be responsible for the interaction with PikAIV. A replacement of this linker region of DEBS1 with the corresponding region of PikAI led to a 95% decrease in TKL levels in S. venezuelae, consistent with this hypothesis.
Collapse
Affiliation(s)
- Beom Seok Kim
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | | | | | | | |
Collapse
|
29
|
Florova G, Kazanina G, Reynolds KA. Enzymes involved in fatty acid and polyketide biosynthesis in Streptomyces glaucescens: role of FabH and FabD and their acyl carrier protein specificity. Biochemistry 2002; 41:10462-71. [PMID: 12173933 DOI: 10.1021/bi0258804] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Malonyl acyl carrier protein (ACP) is used as an extender unit in each of the elongation steps catalyzed by the type II dissociated fatty acid synthase (FAS) and polyketide synthase (PKS) of Streptomyces glaucescens. Initiation of straight-chain fatty acid biosynthesis by the type II FAS involves a direct condensation of acetyl-CoA with this malonyl-ACP to generate a 3-ketobutyryl-ACP product and is catalyzed by FabH. In vitro experiments with a reconstituted type II PKS system in the absence of FabH have previously shown that the acetyl-ACP (generated by decarboxylation of malonyl-ACP), not acetyl-CoA, is used to initiate tetracenomycin C (TCM C) biosynthesis. We have shown that sgFabH activity is present in S. glaucescens fermentations during TCM C production, suggesting that it could contribute to initiation of TCM C biosynthesis in vivo. Isotope incorporation studies with [CD3]acetate and [13CD3]acetate demonstrated significant intact retention of three deuteriums into the starter unit of palmitate and complete washout of deuterium label into the starter unit of TCM C. These observations provide evidence that acetyl-CoA is not used directly as a starter unit for TCM C biosynthesis in vivo and argue against an involvement of FabH in this process. Consistent with this conclusion, assays of the purified recombinant sgFabH with acetyl-CoA demonstrated activity using malonyl-ACP generated from either FabC (the S. glaucescens FAS ACP) (k(cat) 42.2 min(-1), K(m) 4.5 +/- 0.3 microM) or AcpP (the E. coli FAS ACP) (k(cat) 7.5 min(-1), K(m) 6.3 +/- 0.3 microM) but not TcmM (the S. glaucescens PKS ACP). In contrast, the sgFabD which catalyzes conversion of malonyl-CoA to malonyl-ACP for fatty acid biosynthesis was shown to be active with TcmM (k(cat) 150 min(-1), K(m) 12.2 +/- 1.2 microM), AcpP (k(cat) 141 min(-1), K(m) 13.2 +/- 1.6 microM), and FabC (k(cat) 560 min(-1), K(m) 12.7 +/- 2.6 microM). This enzyme was shown to be present during TCM C production and could play a role in generating malonyl-ACP for both processes. Previous demonstrations that the purified PKS ACPs catalyze self-malonylation and that a FabD activity is not required for polyketide biosynthesis are shown to be an artifact of the expression and purification protocols. The relaxed ACP specificity of FabD and the lack of a clear alternative are consistent with a role of FabD in providing malonyl-ACP precursors for PKS as well as FAS processes. In contrast, the ACP specificity of FabH, isotope labeling studies, and a demonstrated alternative mechanism for initiation of the PKS process provide unequivocal evidence that FabH is involved only in the FAS process.
Collapse
Affiliation(s)
- Galina Florova
- Department for Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | |
Collapse
|
30
|
Lobo S, Florova G, Reynolds KA. A Streptomyces collinus thiolase with novel acetyl-CoA:acyl carrier protein transacylase activity. Biochemistry 2001; 40:11955-64. [PMID: 11570897 DOI: 10.1021/bi011325a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetyl-CoA:acyl carrier protein (ACP) transacylase (ACT) activity has been demonstrated for the 3-ketoacyl-ACP synthase III (KASIII) which initiates fatty acid biosynthesis in the type II dissociable fatty acid synthases of plants and bacteria. Several lines of evidence have indicated the possibility of ACT activity being associated with proteins other than KASIII. Using a crude extract of Streptomyces collinus, we have resolved from KASIII an additional protein with ACT activity and subsequently purified it 85-fold in five chromatographic steps. The 45 kDa protein was shown by gel filtration to have a molecular mass of 185 +/- 35 kDa, consistent with a homotetrameric structure for the native enzyme. The corresponding gene (fadA) was cloned and sequenced and shown to encode a protein with amino acid sequence homology to type II thiolases. The fadA was expressed in Escherichia coli, and the resulting recombinant FadA enzyme purified by metal chelate chromatography was shown to have both ACT and thiolase activities. Kinetic studies revealed that in an ACT assay FadA had a substrate specificity for a two-carbon acetyl-CoA substrate (K(m) 8.7 +/- 1.4 microM) but was able to use ACPs from both type II fatty acid and polyketide synthases (Streptomyces glaucescens FabC ACP, K(m) 10.7 +/- 1.4 microM; E. coli FabC ACP, K(m) 8.8 +/- 2 microM; FrenN ACP, K(m) 44 +/- 12 microM). In the thiolase assay kinetic analyses revealed similar K(m) values for binding of substrates acetoacetyl-CoA (K(m) 9.8 +/- 0.8 microM) and CoA (K(m) 10.9 +/- 1.8 microM). A Cys92Ser mutant of FadA possessed virtually unchanged K(m) values for acetoacetyl-CoA and CoA but had a greater than 99% decrease in k(cat) for the thiolase activity. No detectable ACT activity was observed for the Cys92Ser mutant, demonstrating that both activities are associated with FadA and likely involve formation of the same covalent acetyl-S-Cys enzyme intermediate. An ACT activity with ACP has not previously been observed for thiolases and in the case of the S. collinus FadA is significantly lower (k(cat) 3 min(-1)) than the thiolase activity of FadA (k(cat) 2170 min(-1)). The ACT activity of FadA is comparable to the KAS activity and significantly higher than the ACT activity, reported for a streptomycete KASIII.
Collapse
Affiliation(s)
- S Lobo
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | |
Collapse
|
31
|
Revill WP, Bibb MJ, Scheu AK, Kieser HJ, Hopwood DA. Beta-ketoacyl acyl carrier protein synthase III (FabH) is essential for fatty acid biosynthesis in Streptomyces coelicolor A3(2). J Bacteriol 2001; 183:3526-30. [PMID: 11344162 PMCID: PMC99652 DOI: 10.1128/jb.183.11.3526-3530.2001] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Streptomyces coelicolor fab (fatty acid biosynthesis) gene cluster (fabD-fabH-acpP-fabF) is cotranscribed to produce a leaderless mRNA transcript. One of these genes, fabH, encodes a ketoacyl synthase III that is essential to and is proposed to be responsible for initiation of fatty acid biosynthesis in S. coelicolor.
Collapse
Affiliation(s)
- W P Revill
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom.
| | | | | | | | | |
Collapse
|
32
|
Smirnova N, Reynolds KA. Engineered fatty acid biosynthesis in Streptomyces by altered catalytic function of beta-ketoacyl-acyl carrier protein synthase III. J Bacteriol 2001; 183:2335-42. [PMID: 11244075 PMCID: PMC95142 DOI: 10.1128/jb.183.7.2335-2342.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Streptomyces glaucescens beta-ketoacyl-acyl carrier protein (ACP) synthase III (KASIII) initiates straight- and branched-chain fatty acid biosynthesis by catalyzing the decarboxylative condensation of malonyl-ACP with different acyl-coenzyme A (CoA) primers. This KASIII has one cysteine residue, which is critical for forming an acyl-enzyme intermediate in the first step of the process. Three mutants (Cys122Ala, Cys122Ser, Cys122Gln) were created by site-directed mutagenesis. Plasmid-based expression of these mutants in S. glaucescens resulted in strains which generated 75 (Cys122Ala) to 500% (Cys122Gln) more straight-chain fatty acids (SCFA) than the corresponding wild-type strain. In contrast, plasmid-based expression of wild-type KASIII had no effect on fatty acid profiles. These observations are attributed to an uncoupling of the condensation and decarboxylation activities in these mutants (malonyl-ACP is thus converted to acetyl-ACP, a SCFA precursor). Incorporation experiments with perdeuterated acetic acid demonstrated that 9% of the palmitate pool of the wild-type strain was generated from an intact D(3) acetyl-CoA starter unit, compared to 3% in a strain expressing the Cys122Gln KASIII. These observations support the intermediacy of malonyl-ACP in generating the SCFA precursor in a strain expressing this mutant. To study malonyl-ACP decarboxylase activity in vitro, the KASIII mutants were expressed and purified as His-tagged proteins in Escherichia coli and assayed. In the absence of the acyl-CoA substrate the Cys122Gln mutant and wild-type KASIII were shown to have comparable decarboxylase activities in vitro. The Cys122Ala mutant exhibited higher activity. This activity was inhibited for all enzymes by the presence of high concentrations of isobutyryl-CoA (>100 microM), a branched-chain fatty acid biosynthetic precursor. Under these conditions the mutant enzymes had no activity, while the wild-type enzyme functioned as a ketoacyl synthase. These observations indicate the likely upper and lower limits of isobutyryl-CoA and related acyl-CoA concentrations within S. glaucescens.
Collapse
Affiliation(s)
- N Smirnova
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | |
Collapse
|
33
|
Zhang W, Reynolds KA. MeaA, a putative coenzyme B12-dependent mutase, provides methylmalonyl coenzyme A for monensin biosynthesis in Streptomyces cinnamonensis. J Bacteriol 2001; 183:2071-80. [PMID: 11222607 PMCID: PMC95104 DOI: 10.1128/jb.183.6.2071-2080.2001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ratio of the major monensin analogs produced by Streptomyces cinnamonensis is dependent upon the relative levels of the biosynthetic precursors methylmalonyl-coenzyme A (CoA) (monensin A and monensin B) and ethylmalonyl-CoA (monensin A). The meaA gene of this organism was cloned and sequenced and was shown to encode a putative 74-kDa protein with significant amino acid sequence identity to methylmalonyl-CoA mutase (MCM) (40%) and isobutyryl-CoA mutase (ICM) large subunit (36%) and small subunit (52%) from the same organism. The predicted C terminus of MeaA contains structural features highly conserved in all coenzyme B12-dependent mutases. Plasmid-based expression of meaA from the ermE* promoter in the S. cinnamonensis C730.1 strain resulted in a decreased ratio of monensin A to monensin B, from 1:1 to 1:3. Conversely, this ratio increased to 4:1 in a meaA mutant, S. cinnamonensis WM2 (generated from the C730.1 strain by insertional inactivation of meaA by using the erythromycin resistance gene). In both of these experiments, the overall monensin titers were not significantly affected. Monensin titers, however, did decrease over 90% in an S. cinnamonensis WD2 strain (an icm meaA mutant). Monensin titers in the WD2 strain were restored to at least wild-type levels by plasmid-based expression of the meaA gene or the Amycolatopsis mediterranei mutAB genes (encoding MCM). In contrast, growth of the WD2 strain in the presence of 0.8 M valine led only to a partial restoration (<25%) of monensin titers. These results demonstrate that the meaA gene product is significantly involved in methylmalonyl-CoA production in S. cinnamonensis and that under the tested conditions the presence of both MeaA and ICM is crucial for monensin production in the WD2 strain. These results also indicate that valine degradation, implicated in providing methylmalonyl-CoA precursors for many polyketide biosynthetic processes, does not do so to a significant degree for monensin biosynthesis in the WD2 mutant.
Collapse
Affiliation(s)
- W Zhang
- Institute for Structural Biology and Drug Discovery and Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | |
Collapse
|
34
|
Cropp TA, Wilson DJ, Reynolds KA. Identification of a cyclohexylcarbonyl CoA biosynthetic gene cluster and application in the production of doramectin. Nat Biotechnol 2000; 18:980-3. [PMID: 10973220 DOI: 10.1038/79479] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The side chain of the antifungal antibiotic ansatrienin A from Streptomyces collinus contains a cyclohexanecarboxylic acid (CHC)-derived moiety. This moiety is also observed in trace amounts of omega-cyclohexyl fatty acids (typically less than 1% of total fatty acids) produced by S. collinus. Coenzyme A-activated CHC (CHC-CoA) is derived from shikimic acid through a reductive pathway involving a minimum of nine catalytic steps. Five putative CHC-CoA biosynthetic genes in the ansatrienin biosynthetic gene cluster of S. collinus have been identified. Plasmid-based heterologous expression of these five genes in Streptomyces avermitilis or Streptomyces lividans allows for production of significant amounts of omega-cyclohexyl fatty acids (as high as 49% of total fatty acids). In the absence of the plasmid these organisms are dependent on exogenously supplied CHC for omega-cyclohexyl fatty acid production. Doramectin is a commercial antiparasitic avermectin analog produced by fermenting a bkd mutant of S. avermitilis in the presence of CHC. Introduction of the S. collinus CHC-CoA biosynthetic gene cassette into this organism resulted in an engineered strain able to produce doramectin without CHC supplementation. The CHC-CoA biosynthetic gene cluster represents an important genetic tool for precursor-directed biosynthesis of doramectin and has potential for directed biosynthesis in other important polyketide-producing organisms.
Collapse
Affiliation(s)
- T A Cropp
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, 800 E. Leigh St. Suite 212, Richmond, VA 23219, USA
| | | | | |
Collapse
|
35
|
Patton SM, Cropp TA, Reynolds KA. A novel delta(3),delta(2)-enoyl-CoA isomerase involved in the biosynthesis of the cyclohexanecarboxylic acid-derived moiety of the polyketide ansatrienin A. Biochemistry 2000; 39:7595-604. [PMID: 10858310 DOI: 10.1021/bi0005714] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The side chain of the antifungal polyketide ansatrienin A produced by Streptomyces collinus contains a cyclohexanecarboxylic acid (CHC) derived moiety. This CHC in the coenzyme A activated form (CHC-CoA) is derived from shikimic acid via a pathway in which the penultimate step is the isomerization of 2-cyclohexenylcarbonyl-CoA to 1-cyclohexenylcarbonyl-CoA. We have purified a 28 kDa 2-cyclohexenylcarbonyl-CoA isomerase (ChcB) from S. collinus and cloned and sequenced the corresponding chcB gene. The predicted amino acid sequence of ChcB showed moderate sequence identity to members of the hydratase/isomerase superfamily of enzymes. The recombinant ChcB was overexpressed in Escherichia coli and purified to homogeneity using metal chelate chromatography. Kinetic analysis demonstrated that recombinant ChcB had wide substrate specificity and could catalyze a double bond isomerization using 2-cyclohexenylcarbonyl-CoA (K(m) 116 +/- 68 microM, k(cat)( )()3.7 +/- 1.0 min(-)(1)), trans-3-hexenyl-CoA (K(m) 39 +/- 10 microM, k(cat)( )()12.8 +/- 1 min(-)(1)), and vinylacetyl-CoA (K(m) 156 +/- 34 microM, k(cat)( )()29 +/- 3 min(-)(1)) as substrates. ChcB activity in cell extracts of S. collinus SP1, an insertionally disrupted chcB mutant, was shown to decrease by more than 99% (as compared to the wild-type strain) using all three of these substrates. The S. collinus SP1 strain, unlike the wild-type strain, could not produce omega-cyclohexyl fatty acids but was still able to grow efficiently on methyl oleate as a sole carbon source. These observations demonstrate that the S. collinus ChcB is required for catalyzing the isomerization of 2-cyclohexenylcarbonyl-CoA to 1-cyclohexenylcarbonyl-CoA during CHC-CoA biosynthesis but not for degradation of unsaturated fatty acids. The chcB gene does not appear to be associated with the ansatrienin biosynthetic gene cluster, which has previously been shown to contain at least one gene known to be essential for CHC-CoA biosynthesis. This finding represents a notable exception to the general rule regarding the clustering of polyketide biosynthetic pathway genes.
Collapse
Affiliation(s)
- S M Patton
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond 23219, USA
| | | | | |
Collapse
|
36
|
Cropp TA, Smogowicz AA, Hafner EW, Denoya CD, McArthur HAI, Reynolds KA. Fatty-acid biosynthesis in a branched-chain α-keto acid dehydrogenase mutant ofStreptomyces avermitilis. Can J Microbiol 2000. [DOI: 10.1139/w00-028] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fatty-acid biosynthesis by a branched-chain alpha-keto acid dehydrogenase (bkd) mutant of Streptomyces avermitilis was analyzed. This mutant is unable to produce the appropriate precursors of branched-chain fatty acid (BCFA) biosynthesis, but unlike the comparable Bacillus subtilis mutant, was shown not to have an obligate growth requirement for these precursors. The bkd mutant produced only straight-chain fatty acids (SCFAs) with membrane fluidity provided entirely by unsaturated fatty acids (UFAs), the levels of which increased dramatically compared to the wild-type strain. The levels of UFAs increased in both the wild-type and bkd mutant strains as the growth temperature was lowered from 37°C to 24°C, suggesting that a regulatory mechanism exists to alter the proportion of UFAs in response either to a loss of BCFA biosynthesis, or a decreased growth temperature. No evidence of a regulatory mechanism for BCFAs was observed, as the types of these fatty acids, which contribute significantly to membrane fluidity, did not alter when the wild-type S. avermitilis was grown at different temperatures. The principal UFA produced by S. avermitilis was shown to be delta9-hexadecenoate, the same fatty acid produced by Escherichia coli. This observation, and the inability of S. avermitilis to convert exogenous labeled palmitate to the corresponding UFA, was shown to be consistent with an anaerobic pathway for UFA biosynthesis. Incorporation studies with theS. avermitilis bkd mutant demonstrated that the fatty acid synthase has a remarkably broad substrate specificity and is able to process a wide range of exogenous branched chain carboxylic acids into unusual BCFAs.Key words: Streptomyces avermitilis, fatty acid biosynthesis, avermectin.
Collapse
|
37
|
Liu H, Reynolds KA. Role of crotonyl coenzyme A reductase in determining the ratio of polyketides monensin A and monensin B produced by Streptomyces cinnamonensis. J Bacteriol 1999; 181:6806-13. [PMID: 10542184 PMCID: PMC94147 DOI: 10.1128/jb.181.21.6806-6813.1999] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ccr gene, encoding crotonyl coenzyme A (CoA) reductase (CCR), was cloned from Streptomyces cinnamonensis C730.1 and shown to encode a protein with 90% amino acid sequence identity to the CCRs of Streptomyces collinus and Streptomyces coelicolor. A ccr-disrupted mutant, S. cinnamonensis L1, was constructed by inserting the hyg resistance gene into a unique BglII site within the ccr coding region. By use of the ermE* promoter, the S. collinus ccr gene was expressed from plasmids in S. cinnamonensis C730. 1/pHL18 and L1/pHL18. CCR activity in mutant L1 was shown to decrease by more than 90% in both yeast extract-malt extract (YEME) medium and a complex fermentation medium, compared to that in wild-type C730.1. Compared to C730.1, mutants C730.1/pHL18 and L1/pHL18 exhibited a huge increase in CCR activity (14- and 13-fold, respectively) in YEME medium and a moderate increase (3.7- and 2. 7-fold, respectively) in the complex fermentation medium. In the complex fermentation medium, S. cinnamonensis L1 produced monensins A and B in a ratio of 12:88, dramatically lower than the 50:50 ratio observed for both C730.1 and C730.1/pHL18. Plasmid (pHL18)-based expression of the S. collinus ccr gene in mutant L1 increased the monensin A/monensin B ratio to 42:58. Labeling experiments with [1, 2-(13)C(2)]acetate demonstrated the same levels of intact incorporation of this material into the butyrate-derived portion of monensin A in both C730.1 and mutant C730.1/pLH18 but a markedly decreased level of such incorporation in mutant L1. The addition of crotonic acid at 15 mM led to significant increases in the monensin A/monensin B ratio in C730.1 and C730.1/pHL18 but had no effect in S. cinnamonensis L1. These results demonstrate that CCR plays a significant role in providing butyryl-CoA for monensin A biosynthesis and is present in wild-type S. cinnamonensis C730.1 at a level sufficient that the availability of the appropriate substrate (crotonyl-CoA) is limiting.
Collapse
Affiliation(s)
- H Liu
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | |
Collapse
|
38
|
Bao W, Sheldon PJ, Hutchinson CR. Purification and properties of the Streptomyces peucetius DpsC beta-ketoacyl:acyl carrier protein synthase III that specifies the propionate-starter unit for type II polyketide biosynthesis. Biochemistry 1999; 38:9752-7. [PMID: 10423255 DOI: 10.1021/bi990751h] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biosynthesis of the polyketide-derived carbon skeleton of daunorubicin (DNR) begins with propionate rather than acetate, which is the starter unit for most other aromatic polyketides. The dpsCgene has been implicated in specifying the unique propionate-starter unit, and it encodes a protein that is very similar to the Escherichia coli beta-ketoacyl:acyl carrier protein (ACP) synthase III (FabH or KS III) enzyme of fatty acid biosynthesis. Purified DpsC was found to use propionyl-coenzyme A as substrate and to be acylated by propionate at the Ser-118 residue. DpsC exhibits KS III activity in catalyzing the condensation of propionyl-CoA and malonyl-ACP, and also functions as an acyltransferase in the transfer of propionate to an ACP. The DpsC enzyme has a high-substrate specificity, utilizing only propionyl-CoA, and not malonyl-CoA, 2-methylmalonyl-CoA or acetyl-CoA, as the starter unit of DNR biosynthesis.
Collapse
Affiliation(s)
- W Bao
- School of Pharmacy and Department of Bacteriology, University of Wisconsin, Madison 53706, USA
| | | | | |
Collapse
|
39
|
Han L, Lobo S, Reynolds KA. Characterization of beta-ketoacyl-acyl carrier protein synthase III from Streptomyces glaucescens and its role in initiation of fatty acid biosynthesis. J Bacteriol 1998; 180:4481-6. [PMID: 9721286 PMCID: PMC107458 DOI: 10.1128/jb.180.17.4481-4486.1998] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Streptomyces glaucescens fabH gene, encoding beta-ketoacyl-acyl carrier protein (beta-ketoacyl-ACP) synthase (KAS) III (FabH), was overexpressed in Escherichia coli, and the resulting gene product was purified to homogeneity by metal chelate chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the purified protein revealed an Mr of 37,000, while gel filtration analysis determined a native Mr of 72,000 +/- 3,000 (mean +/- standard deviation), indicating that the enzyme is homodimeric. The purified recombinant protein demonstrated both KAS activity and acyl coenzyme A (acyl-CoA):ACP transacylase (ACAT) activity in a 1:0.12 ratio. The KAS and ACAT activities were both sensitive to thiolactomycin inhibition. The KAS activity of the protein demonstrated a Km value of 3.66 microM for the malonyl-ACP substrate and an unusual broad specificity for acyl-CoA substrates, with Km values of 2.4 microM for acetyl-CoA, 0.71 microM for butyryl-CoA, and 0.41 microM for isobutyryl-CoA. These data suggest that the S. glaucescens FabH is responsible for initiating both straight- and branched-chain fatty acid biosynthesis in Streptomyces and that the ratio of the various fatty acids produced by this organism will be dictated by the ratios of the various acyl-CoA substrates that can react with FabH. Results from a series of in vivo directed biosynthetic experiments in which the ratio of these acyl-CoA substrates was varied are consistent with this hypothesis. An additional set of in vivo experiments using thiolactomycin provides support for the role of FabH and further suggests that a FabH-independent pathway for straight-chain fatty acid biosynthesis operates in S. glaucescens.
Collapse
Affiliation(s)
- L Han
- Department of Medicinal Chemistry and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | | | | |
Collapse
|
40
|
Affiliation(s)
- B J Rawlings
- Department of Chemistry, University of Leicester, UK.
| |
Collapse
|
41
|
Annous BA, Becker LA, Bayles DO, Labeda DP, Wilkinson BJ. Critical role of anteiso-C15:0 fatty acid in the growth of Listeria monocytogenes at low temperatures. Appl Environ Microbiol 1997; 63:3887-94. [PMID: 9327552 PMCID: PMC168698 DOI: 10.1128/aem.63.10.3887-3894.1997] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Listeria monocytogenes is a food-borne pathogen capable of growth at refrigeration temperatures. Membrane lipid fatty acids are major determinants of a sufficiently fluid membrane state to allow growth at low temperatures. L. monocytogenes was characterized by a fatty acid profile dominated to an unusual extent (> 95%) by branched-chain fatty acids, with the major fatty acids being anteiso-C15:0, anteiso-C17:0, and iso-C15:0 in cultures grown in complex or defined media at 37 degrees C. Determination of the fatty acid composition of L. monocytogenes 10403S and SLCC 53 grown over the temperature range 45 to 5 degrees C revealed two modes of adaptation of fatty acid composition to lower growth temperatures: (i) shortening of fatty acid chain length and (ii) alteration of branching from iso to anteiso. Two transposon Tn917-induced cold-sensitive mutants incapable of growth at low temperatures had dramatically altered fatty acid compositions with low levels of i-C15:0, a-C15:0, and a-C17:0 and high levels of i-C14:0, C14:0, i-C16:0, and C16:0. The levels of a-C15:0 and a-C17:0 and the ability to grow at low temperatures were restored by supplementing media with 2-methylbutyric acid, presumably because it acted as a precursor of methylbutyryl coenzyme A, the primer for synthesis of anteiso odd-numbered fatty acids. When mid-exponential-phase 10403S cells grown at 37 degrees C were temperature down-shocked to 5 degrees C they were able, for the most part, to reinitiate growth before the membrane fatty acid composition had reset to a composition more typical for low-temperature growth. No obvious evidence was found for a role for fatty acid unsaturation in adaptation of L. monocytogenes to cold temperature. The switch to a fatty acid profile dominated by a-C15:0 at low temperatures and the association of cold sensitivity with deficiency of a-C15:0 focus attention on the critical role of this fatty acid in growth of L. monocytogenes in the cold, presumably through its physical properties and their effects, in maintaining a fluid, liquid-crystalline state of the membrane lipids.
Collapse
Affiliation(s)
- B A Annous
- Department of Biological Sciences, Illinois State University, Normal 61790-4120, USA
| | | | | | | | | |
Collapse
|
42
|
Abstract
ccr encoding crotonyl coenzyme A (CoA) reductase (CCR), which catalyzes the conversion of crotonyl-CoA to butyryl-CoA in the presence of NADPH, was previously cloned from Streptomyces collinus. We now report that a complete open reading frame, designated meaA, is located downstream from ccr. The predicted gene product showed 35% identity with methylmalonyl-CoA mutases from various sources. In addition, the predicted amino acid sequences of S. collinus ccr and meaA exhibit strong similarity to that of adhA (43% identity), a putative alcohol dehydrogenase gene, and meaA (62% identity) of Methylobacterium extorquens, respectively. Both adhA and meaA are involved in the assimilation of C1 and C2 compounds in an unknown pathway in the isocitrate lyase (ICL)-negative Methylobacterium. We have demonstrated that S. collinus can grow with acetate as its sole carbon source even though there is no detectable ICL, suggesting that in this organism ccr and meaA may also be involved in a pathway for the assimilation of C2 compounds. Previous studies with streptomycetes provided a precedent for a pathway that initiates with the condensation of two acetyl-CoA molecules to form butyryl-CoA, which is then transformed to succinyl-CoA with two separate CoB12-mediated rearrangements and a series of oxidations. The biological functions of ccr and meaA in this process were investigated by gene disruption. A ccr-blocked mutant showed no detectable crotonyl-CoA reductase activity and, compared to the wild-type strain, exhibited dramatically reduced growth when acetate was the sole carbon source. An meaA-blocked mutant also exhibited reduced growth on acetate. However, both methylmalonyl-CoA mutase and isobutyryl-CoA mutase, which catalyze the two CoB12-dependent rearrangements in this proposed pathway, were shown to be present in the meaA-blocked mutant. These results suggested that both ccr and meaA are involved in a novel pathway for the growth of S. collinus when acetate is its sole carbon source.
Collapse
Affiliation(s)
- L Han
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, 21201, USA
| | | |
Collapse
|
43
|
Wallace KK, Lobo S, Han L, McArthur HA, Reynolds KA. In vivo and in vitro effects of thiolactomycin on fatty acid biosynthesis in Streptomyces collinus. J Bacteriol 1997; 179:3884-91. [PMID: 9190803 PMCID: PMC179196 DOI: 10.1128/jb.179.12.3884-3891.1997] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A stable-isotope assay was used to analyze the effectiveness of various perdeuterated short-chain acyl coenzyme A (acyl-CoA) compounds as starter units for straight- and branched-chain fatty acid biosynthesis in cell extracts of Streptomyces collinus. In these extracts perdeuterated isobutyryl-CoA was converted to isopalmitate (a branched-chain fatty acid), while butyryl-CoA was converted to palmitate (a straight-chain fatty acid). These observations are consistent with previous in vivo analyses of fatty acid biosynthesis in S. collinus, which suggested that butyryl-CoA and isobutyryl-CoA function as starter units for palmitate and isopalmitate biosynthesis, respectively. Additionally, in vitro analysis demonstrated that acetyl-CoA can function as a starter unit for palmitate biosynthesis. Palmitate biosynthesis and isopalmitate biosynthesis in these cell extracts were both effectively inhibited by thiolactomycin, a known type II fatty acid synthase inhibitor. In vivo experiments demonstrated that concentrations of thiolactomycin ranging from 0.1 to 0.2 mg/ml produced both a dramatic decrease in the cellular levels of branched-chain fatty acids and a surprising three- to fivefold increase in the cellular levels of the straight-chain fatty acids palmitate and myristate. Additional in vivo incorporation studies with perdeuterated butyrate suggested that, in accord with the in vitro studies, the biosynthesis of the palmitate from butyryl-CoA decreases in the presence of thiolactomycin. In contrast, in vivo incorporation studies with perdeuterated acetate demonstrated that the biosynthesis of palmitate from acetyl-CoA increases in the presence of thiolactomycin. These observations clearly demonstrate that isobutyryl-CoA is a starter unit for isopalmitate biosynthesis and that either acetyl-CoA or butyryl-CoA can be a starter unit for palmitate biosynthesis in S. collinus. However, the pathway for palmitate biosynthesis from acetyl-CoA is less sensitive to thiolactomycin, and it is suggested that the basis for this difference is in the initiation step.
Collapse
Affiliation(s)
- K K Wallace
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, 21201, USA
| | | | | | | | | |
Collapse
|
44
|
Gandecha AR, Large SL, Cundliffe E. Analysis of four tylosin biosynthetic genes from the tylLM region of the Streptomyces fradiae genome. Gene 1997; 184:197-203. [PMID: 9031628 DOI: 10.1016/s0378-1119(96)00595-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The tylLM region of the tylosin biosynthetic gene cluster of Streptomyces fradiae contains four open reading frames (orfs1*-4*). The function of the orf1* product is not known. The product of orf2* (tylM2) is the glycosyltransferase that adds mycaminose to the 5-hydroxyl group of tylactone, the polyketide aglycone of tylosin (Ty). A methyltransferase, responsible for 3-N-methylation during mycaminose production, is encoded by orf3* (tylM1). The product of orf4* (cer) is crotonyl-CoA reductase, which converts acetoacetyl-CoA to butyryl-CoA for use as a 4C extender unit during tylactone production.
Collapse
Affiliation(s)
- A R Gandecha
- Department of Biochemistry, University of Leicester, UK
| | | | | |
Collapse
|
45
|
Sajbidor J. Effect of some environmental factors on the content and composition of microbial membrane lipids. Crit Rev Biotechnol 1997; 17:87-103. [PMID: 9192472 DOI: 10.3109/07388559709146608] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lipids are known as a part of an effective adaptation mechanism reflecting the changes in the extracellular environment. The fluidity of biological membranes is influenced by the lipid structure and the portion of saturated, unsaturated, branched, or cyclic fatty acids in individual phospholipids. For all living organisms undergoing environmental adaptation, the fluidity can be changed only to a relatively small extent. This range is genetically determined and it is specific for every microorganism. This article presents recent knowledge about the influence of some environmental parameters (temperature, osmotic pressure, pH, the presence of salt or ethanol in medium) on a microbial membrane with the emphasis on regulation aspect in fatty acid biosynthesis. The main tools for regulation of membrane fluidity, for example, fatty acid desaturation or incorporation of branched and cyclic fatty acids into phospholipids, are discussed in more detail.
Collapse
Affiliation(s)
- J Sajbidor
- Department of Biochemical Technology, Faculty of Chemical Technology, Slovak Technical University, Bratislava
| |
Collapse
|
46
|
Wang P, Denoya CD, Morgenstern MR, Skinner DD, Wallace KK, Digate R, Patton S, Banavali N, Schuler G, Speedie MK, Reynolds KA. Cloning and characterization of the gene encoding 1-cyclohexenylcarbonyl coenzyme A reductase from Streptomyces collinus. J Bacteriol 1996; 178:6873-81. [PMID: 8955309 PMCID: PMC178588 DOI: 10.1128/jb.178.23.6873-6881.1996] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We report the cloning of the gene encoding the 1-cyclohexenylcarbonyl coenzyme A reductase (ChcA) of Streptomyces collinus, an enzyme putatively involved in the final reduction step in the formation of the cyclohexyl moiety of ansatrienin from shikimic acid. The cloned gene, with a proposed designation of chcA, encodes an 843-bp open reading frame which predicts a primary translation product of 280 amino acids and a calculated molecular mass of 29.7 kDa. Highly significant sequence similiarity extending along almost the entire length of the protein was observed with members of the short-chain alcohol dehydrogenase superfamily. The S. collinus chcA gene was overexpressed in Escherichia coli by using a bacteriophage T7 transient expression system, and a protein with a specific ChcA activity was detected. The E. coli-produced ChcA protein was purified and shown to have similar steady-state kinetics and electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels as the enoyl-coenzyme A reductase protein prepared from S. collinus. The enzyme demonstrated the ability to catalyze, in vitro, three of the reductive steps involved in the formation of cyclohexanecarboxylic acid. An S. collinus chcA mutant, constructed by deletion of a genomic region comprising the 5' end of chcA, lost the ChcA activity and the ability to synthesize either cyclohexanecarboxylic acid or ansatrienin. These results suggest that chcA encodes the ChcA that is involved in catalyzing multiple reductive steps in the pathway that provides the cyclohexanecarboxylic acid from shikimic acid.
Collapse
Affiliation(s)
- P Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, 21201, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|