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Tsakem B, Li G, Teponno RB. Structures, biosynthesis and biological activities of benastatins, anthrabenzoxocinones and fredericamycins. Bioorg Chem 2024; 150:107572. [PMID: 38901281 DOI: 10.1016/j.bioorg.2024.107572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 06/16/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
The fast spread of antibiotic resistance results in the requirement for a constant introduction of new candidates. Pentangular polyphenols, a growing family of actinomycetes-derived aromatic type II polyketides, have attracted considerable attention due to their intriguing polycyclic systems and potent antimicrobial activity. Among them, benastatins, anthrabenzoxocinones (ABXs), and fredericamycins, display unique variations in their polycyclic frameworks, yet concurrently share structural commonalities within their substitutions. The present review summarizes advances in the isolation, spectroscopic characteristics, biosynthesis, and biological activities of pentangular polyphenols benastatins (1-16), ABXs (17-39), and fredericamycins (40-42) from actinomycetes. The information presented here thus prompts researchers to further explore and discover additional congeners within these three small classes of pentangular polyphenols.
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Affiliation(s)
- Bienvenu Tsakem
- Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon
| | - Gang Li
- China-Cameroon Joint Laboratory on Bioactive Natural Products from Endophytes, Department of Natural Medicinal Chemistry and Pharmacognosy, School of Pharmacy, Qingdao University, Qingdao 266071, People's Republic of China.
| | - Rémy Bertrand Teponno
- Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
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2
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Heo KT, Lee B, Hwang GJ, Park B, Jang JP, Hwang BY, Jang JH, Hong YS. A unique dual acyltransferase system shared in the polyketide chain initiation of kidamycinone and rubiflavinone biosynthesis. Front Microbiol 2023; 14:1274358. [PMID: 38029143 PMCID: PMC10646177 DOI: 10.3389/fmicb.2023.1274358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/04/2023] [Indexed: 12/01/2023] Open
Abstract
The pluramycin family of natural products has diverse substituents at the C2 position, which are closely related to their biological activity. Therefore, it is important to understand the biosynthesis of C2 substituents. In this study, we describe the biosynthesis of C2 moieties in Streptomyces sp. W2061, which produces kidamycin and rubiflavinone C-1, containing anthrapyran aglycones. Sequence analysis of the loading module (Kid13) of the PKS responsible for the synthesis of these anthrapyran aglycones is useful for confirming the incorporation of atypical primer units into the corresponding products. Kid13 is a ketosynthase-like decarboxylase (KSQ)-type loading module with unusual dual acyltransferase (AT) domains (AT1-1 and AT1-2). The AT1-2 domain primarily loads ethylmalonyl-CoA and malonyl-CoA for rubiflavinone and kidamycinone and rubiflavinone, respectively; however, the AT1-1 domain contributed to the functioning of the AT1-2 domain to efficiently load ethylmalonyl-CoA for rubiflavinone. We found that the dual AT system was involved in the production of kidamycinone, an aglycone of kidamycin, and rubiflavinone C-1 by other shared biosynthetic genes in Streptomyces sp. W2061. This study broadens our understanding of the incorporation of atypical primer units into polyketide products.
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Affiliation(s)
- Kyung Taek Heo
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
| | - Byeongsan Lee
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju-si, Republic of Korea
| | - Gwi Ja Hwang
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
| | - Beomcheol Park
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju-si, Republic of Korea
| | - Jun-Pil Jang
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
| | - Bang Yeon Hwang
- College of Pharmacy, Chungbuk National University, Cheongju-si, Republic of Korea
| | - Jae-Hyuk Jang
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
| | - Young-Soo Hong
- Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju-si, Republic of Korea
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3
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Fazal A, Hemsworth GR, Webb ME, Seipke RF. A Standalone β-Ketoreductase Acts Concomitantly with Biosynthesis of the Antimycin Scaffold. ACS Chem Biol 2021; 16:1152-1158. [PMID: 34151573 DOI: 10.1021/acschembio.1c00229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Antimycins are anticancer compounds produced by a hybrid nonribosomal peptide synthetase/polyketide synthase (NRPS/PKS) pathway. The biosynthesis of these compounds is well characterized, with the exception of the standalone β-ketoreductase enzyme AntM that is proposed to catalyze the reduction of the C8 carbonyl of the antimycin scaffold. Inactivation of antM and structural characterization suggested that rather than functioning as a post-PKS tailoring enzyme, AntM acts upon the terminal biosynthetic intermediate while it is tethered to the PKS acyl carrier protein. Mutational analysis identified two amino acid residues (Tyr185 and Phe223) that are proposed to serve as checkpoints controlling substrate access to the AntM active site. Aromatic checkpoint residues are conserved in uncharacterized standalone β-ketoreductases, indicating that they may also act concomitantly with synthesis of the scaffold. These data provide novel mechanistic insights into the functionality of standalone β-ketoreductases and will enable their reprogramming for combinatorial biosynthesis.
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Affiliation(s)
- Asif Fazal
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Glyn R. Hemsworth
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Michael E. Webb
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Ryan F. Seipke
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
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4
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Messiha HL, Payne KAP, Scrutton NS, Leys D. A Biological Route to Conjugated Alkenes: Microbial Production of Hepta-1,3,5-triene. ACS Synth Biol 2021; 10:228-235. [PMID: 33535752 DOI: 10.1021/acssynbio.0c00464] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Conjugated alkenes such as dienes and polyenes have a range of applications as pharmaceutical agents and valuable building blocks in the polymer industry. Development of a renewable route to these compounds provides an alternative to fossil fuel derived production. The enzyme family of the UbiD decarboxylases offers substantial scope for alkene production, readily converting poly unsaturated acids. However, biochemical pathways producing the required substrates are poorly characterized, and UbiD-application has hitherto been limited to biological styrene production. Herein, we present a proof-of-principle study for microbial production of polyenes using a bioinspired strategy employing a polyketide synthase (PKS) in combination with a UbiD-enzyme. Deconstructing a bacterial iterative type II PKS enabled repurposing the broad-spectrum antibiotic andrimid biosynthesis pathway to access the metabolic intermediate 2,4,6-octatrienoic acid, a valuable chemical for material and pharmaceutical industry. Combination with the fungal ferulic acid decarboxylase (Fdc1) led to a biocatalytic cascade-type reaction for the production of hepta-1,3,5-triene in vivo. Our approach provides a novel route to generate unsaturated hydrocarbons and related chemicals and provides a blue-print for future development and application.
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Affiliation(s)
- Hanan L. Messiha
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Karl A. P. Payne
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Future Biomanufacturing Research Hub (Future BRH), Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Nigel S. Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Future Biomanufacturing Research Hub (Future BRH), Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - David Leys
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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5
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Klein JG, Wu Y, Kokona B, Charkoudian LK. Widening the bottleneck: Heterologous expression, purification, and characterization of the Ktedonobacter racemifer minimal type II polyketide synthase in Escherichia coli. Bioorg Med Chem 2020; 28:115686. [PMID: 33069071 DOI: 10.1016/j.bmc.2020.115686] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/16/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Enzyme assemblies such as type II polyketide synthases (PKSs) produce a wide array of bioactive secondary metabolites. While the molecules produced by type II PKSs have found remarkable clinical success, the biosynthetic prowess of these enzymes has been stymied by 1) the inability to reconstitute the bioactivity of the minimal PKS enzymes in vitro and 2) limited exploration of type II PKSs from diverse phyla. To begin filling this unmet need, we expressed, purified, and characterized the ketosynthase chain length factor (KS-CLF) and acyl carrier protein (ACP) from Ktedonobacter racemifer (Kr). Using E. coli as a heterologous host, we obtained soluble proteins in titers signifying improvements over previous KS-CLF heterologous expression efforts. Characterization of these enzymes reveals that KrACP has self-malonylating activity. Sedimentation velocity analytical ultracentrifugation (SV-AUC) analysis of holo-KrACP and KrKS-CLF indicates that these enzymes do not interact in vitro, suggesting that the acylated state of these proteins might play an important role in facilitating biosynthetically relevant interactions. These results lay important groundwork for optimizing the interaction between KrKS-CLF and KrACP and exploring the biosynthetic potential of other non-actinomycete type II PKSs.
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Affiliation(s)
- Joshua G Klein
- Haverford College, Department of Chemistry, Haverford, PA 19041, United States
| | - Yang Wu
- Haverford College, Department of Chemistry, Haverford, PA 19041, United States
| | - Bashkim Kokona
- Haverford College, Department of Chemistry, Haverford, PA 19041, United States.
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Rodríguez Estévez M, Myronovskyi M, Rosenkränzer B, Paululat T, Petzke L, Ristau J, Luzhetskyy A. Novel Fredericamycin Variant Overproduced by a Streptomycin-resistant Streptomyces albus subsp. chlorinus Strain. Mar Drugs 2020; 18:E284. [PMID: 32481766 PMCID: PMC7345809 DOI: 10.3390/md18060284] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/22/2020] [Accepted: 05/27/2020] [Indexed: 11/16/2022] Open
Abstract
Streptomycetes are an important source of natural products potentially applicable in the pharmaceutical industry. Many of these drugs are secondary metabolites whose biosynthetic genes are very often poorly expressed under laboratory cultivation conditions. In many cases, antibiotic-resistant mutants exhibit increased production of natural drugs, which facilitates the identification and isolation of new substances. In this study, we report the induction of a type II polyketide synthase gene cluster in the marine strain Streptomyces albus subsp. chlorinus through the selection of streptomycin-resistant mutants, resulting in overproduction of the novel compound fredericamycin C2 (1). Fredericamycin C2 (1) is structurally related to the potent antitumor drug lead fredericamycin A.
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Affiliation(s)
- Marta Rodríguez Estévez
- Pharmazeutische Biotechnologie, Universität des Saarlandes, 66123 Saarbrücken, Germany; (M.R.E.); (M.M.); (B.R.)
| | - Maksym Myronovskyi
- Pharmazeutische Biotechnologie, Universität des Saarlandes, 66123 Saarbrücken, Germany; (M.R.E.); (M.M.); (B.R.)
| | - Birgit Rosenkränzer
- Pharmazeutische Biotechnologie, Universität des Saarlandes, 66123 Saarbrücken, Germany; (M.R.E.); (M.M.); (B.R.)
| | - Thomas Paululat
- Organische Chemie II, Universität Siegen, 57068 Siegen, Germany;
| | - Lutz Petzke
- BASF SE, 67056 Ludwigshafen, Germany; (L.P.); (J.R.)
| | | | - Andriy Luzhetskyy
- Pharmazeutische Biotechnologie, Universität des Saarlandes, 66123 Saarbrücken, Germany; (M.R.E.); (M.M.); (B.R.)
- Helmholtz-Institut für Pharmazeutische Forschung Saarland, 66123 Saarbrücken, Germany
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Antimicrobial biosynthetic potential and diversity of culturable soil actinobacteria from forest ecosystems of Northeast India. Sci Rep 2020; 10:4104. [PMID: 32139731 PMCID: PMC7057963 DOI: 10.1038/s41598-020-60968-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
Actinobacteria is a goldmine for the discovery of abundant secondary metabolites with diverse biological activities. This study explores antimicrobial biosynthetic potential and diversity of actinobacteria from Pobitora Wildlife Sanctuary and Kaziranga National Park of Assam, India, lying in the Indo-Burma mega-biodiversity hotspot. A total of 107 actinobacteria were isolated, of which 77 exhibited significant antagonistic activity. 24 isolates tested positive for at least one of the polyketide synthase type I, polyketide synthase type II or non-ribosomal peptide synthase genes within their genome. Their secondary metabolite pathway products were predicted to be involved in the production of ansamycin, benzoisochromanequinone, streptogramin using DoBISCUIT database. Molecular identification indicated that these actinobacteria predominantly belonged to genus Streptomyces, followed by Nocardia and Kribbella. 4 strains, viz. Streptomyces sp. PB-79 (GenBank accession no. KU901725; 1313 bp), Streptomyces sp. Kz-28 (GenBank accession no. KY000534; 1378 bp), Streptomyces sp. Kz-32 (GenBank accession no. KY000536; 1377 bp) and Streptomyces sp. Kz-67 (GenBank accession no. KY000540; 1383 bp) showed ~89.5% similarity to the nearest type strain in EzTaxon database and may be considered novel. Streptomyces sp. Kz-24 (GenBank accession no. KY000533; 1367 bp) showed only 96.2% sequence similarity to S. malaysiensis and exhibited minimum inhibitory concentration of 0.024 µg/mL against methicilin resistant Staphylococcus aureus ATCC 43300 and Candida albicans MTCC 227. This study establishes that actinobacteria isolated from the poorly explored Indo-Burma mega-biodiversity hotspot may be an extremely rich reservoir for production of biologically active compounds for human welfare.
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8
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Biosynthesis of Polyketides in Streptomyces. Microorganisms 2019; 7:microorganisms7050124. [PMID: 31064143 PMCID: PMC6560455 DOI: 10.3390/microorganisms7050124] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/24/2019] [Accepted: 04/27/2019] [Indexed: 12/12/2022] Open
Abstract
Polyketides are a large group of secondary metabolites that have notable variety in their structure and function. Polyketides exhibit a wide range of bioactivities such as antibacterial, antifungal, anticancer, antiviral, immune-suppressing, anti-cholesterol, and anti-inflammatory activity. Naturally, they are found in bacteria, fungi, plants, protists, insects, mollusks, and sponges. Streptomyces is a genus of Gram-positive bacteria that has a filamentous form like fungi. This genus is best known as one of the polyketides producers. Some examples of polyketides produced by Streptomyces are rapamycin, oleandomycin, actinorhodin, daunorubicin, and caprazamycin. Biosynthesis of polyketides involves a group of enzyme activities called polyketide synthases (PKSs). There are three types of PKSs (type I, type II, and type III) in Streptomyces responsible for producing polyketides. This paper focuses on the biosynthesis of polyketides in Streptomyces with three structurally-different types of PKSs.
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Nofiani R, Philmus B, Nindita Y, Mahmud T. 3-Ketoacyl-ACP synthase (KAS) III homologues and their roles in natural product biosynthesis. MEDCHEMCOMM 2019; 10:1517-1530. [PMID: 31673313 DOI: 10.1039/c9md00162j] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/29/2019] [Indexed: 11/21/2022]
Abstract
The 3-ketoacyl-ACP synthase (KAS) III proteins are one of the most abundant enzymes in nature, as they are involved in the biosynthesis of fatty acids and natural products. KAS III enzymes catalyse a carbon-carbon bond formation reaction that involves the α-carbon of a thioester and the carbonyl carbon of another thioester. In addition to the typical KAS III enzymes involved in fatty acid and polyketide biosynthesis, there are proteins homologous to KAS III enzymes that catalyse reactions that are different from that of the traditional KAS III enzymes. Those include enzymes that are responsible for a head-to-head condensation reaction, the formation of acetoacetyl-CoA in mevalonate biosynthesis, tailoring processes via C-O bond formation or esterification, as well as amide formation. This review article highlights the diverse reactions catalysed by this class of enzymes and their role in natural product biosynthesis.
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Affiliation(s)
- Risa Nofiani
- Department of Pharmaceutical Sciences , Oregon State University , Corvallis , OR 97333 , USA . .,Department of Chemistry , Universitas Tanjungpura , Pontianak , Indonesia
| | - Benjamin Philmus
- Department of Pharmaceutical Sciences , Oregon State University , Corvallis , OR 97333 , USA .
| | - Yosi Nindita
- Department of Pharmaceutical Sciences , Oregon State University , Corvallis , OR 97333 , USA .
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences , Oregon State University , Corvallis , OR 97333 , USA .
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Lysoquinone-TH1, a New Polyphenolic Tridecaketide Produced by Expressing the Lysolipin Minimal PKS II in Streptomyces albus. Antibiotics (Basel) 2018; 7:antibiotics7030053. [PMID: 29958422 PMCID: PMC6164072 DOI: 10.3390/antibiotics7030053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/12/2018] [Accepted: 06/22/2018] [Indexed: 12/19/2022] Open
Abstract
The structural repertoire of bioactive naphthacene quinones is expanded by engineering Streptomyces albus to express the lysolipin minimal polyketide synthase II (PKS II) genes from Streptomyces tendae Tü 4042 (llpD-F) with the corresponding cyclase genes llpCI-CIII. Fermentation of the recombinant strain revealed the two new polyaromatic tridecaketides lysoquinone-TH1 (7, identified) and TH2 (8, postulated structure) as engineered congeners of the dodecaketide lysolipin (1). The chemical structure of 7, a benzo[a]naphthacene-8,13-dione, was elucidated by NMR and HR-MS and confirmed by feeding experiments with [1,2-13C₂]-labeled acetate. Lysoquinone-TH1 (7) is a pentangular polyphenol and one example of such rare extended polyaromatic systems of the benz[a]napthacene quinone type produced by the expression of a minimal PKS II in combination with cyclases in an artificial system. While the natural product lysolipin (1) has antimicrobial activity in nM-range, lysoquinone-TH1 (7) showed only minor potency as inhibitor of Gram-positive microorganisms. The bioactivity profiling of lysoquinone-TH1 (7) revealed inhibitory activity towards phosphodiesterase 4 (PDE4), an important target for the treatment in human health like asthma or chronic obstructive pulmonary disease (COPD). These results underline the availability of pentangular polyphenolic structural skeletons from biosynthetic engineering in the search of new chemical entities in drug discovery.
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Lamb AL. Breaking a pathogen's iron will: Inhibiting siderophore production as an antimicrobial strategy. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1054-70. [PMID: 25970810 DOI: 10.1016/j.bbapap.2015.05.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 04/29/2015] [Accepted: 05/06/2015] [Indexed: 12/24/2022]
Abstract
The rise of antibiotic resistance is a growing public health crisis. Novel antimicrobials are sought, preferably developing nontraditional chemical scaffolds that do not inhibit standard targets such as cell wall synthesis or the ribosome. Iron scavenging has been proposed as a viable target, because bacterial and fungal pathogens must overcome the nutritional immunity of the host to be virulent. This review highlights the recent work toward exploiting the biosynthetic enzymes of siderophore production for the design of next generation antimicrobials.
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Affiliation(s)
- Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA.
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Waldman AJ, Balskus EP. Lomaiviticin biosynthesis employs a new strategy for starter unit generation. Org Lett 2014; 16:640-3. [PMID: 24383813 PMCID: PMC3965344 DOI: 10.1021/ol403714g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lomaiviticin biosynthesis is thought to utilize a propionyl starter unit for a type II polyketide synthase (PKS). Discovery of the lomaiviticin (lom) biosynthetic gene cluster suggested an unusual method for starter unit generation involving a bifunctional acyltransferase/decarboxylase (AT/DC) thus far observed only in type I PKS pathways. In vitro biochemical characterization of AT/DC Lom62 confirmed its ability to generate a propionyl-acyl carrier protein (ACP), revealing a new role for this enzymatic activity within natural product biosynthesis.
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Affiliation(s)
- Abraham J Waldman
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
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Fitzgerald JT, Charkoudian LK, Watts KR, Khosla C. Analysis and refactoring of the A-74528 biosynthetic pathway. J Am Chem Soc 2013; 135:3752-5. [PMID: 23442197 DOI: 10.1021/ja311579s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A-74528 is a C30 polyketide natural product that functions as an inhibitor of 2',5'-oligoadenylate phosphodiesterase (2'-PDE), a key regulatory enzyme of the interferon pathway. Modulation of 2'-PDE represents a unique therapeutic approach for regulating viral infections. The gene cluster responsible for biosynthesis of A-74528 yields minute amounts of this natural product together with considerably larger quantities of a structurally dissimilar C30 cytotoxic agent, fredericamycin. Through construction and analysis of a series of knockout mutants, we identified the genes necessary for A-74528 biosynthesis. Remarkably, the formation of six stereocenters and the regiospecific formation of six rings in A-74528 appear to be catalyzed by only two tailoring enzymes, a cyclase and an oxygenase, in addition to the core polyketide synthase. The inferred pathway was genetically refactored in a heterologous host, Streptomyces coelicolor CH999, to produce 3 mg/L A-74528 in the absence of fredericamycin.
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Affiliation(s)
- Jay T Fitzgerald
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Abstract
Recursive pathways are broadly defined as those that catalyze a series of reactions such that the key, bond-forming functional group of the substrate is always regenerated in each cycle, allowing for a new cycle of reactions to begin. Recursive carbon-chain elongation pathways in nature produce fatty acids, polyketides, isoprenoids and α-keto acids (αKAs), which all use modular or iterative approaches for chain elongation. Recently, an artificial pathway for αKA elongation has been built that uses an engineered isopropylmalate synthase to recursively condense acetyl-CoA with αKAs. This synthetic approach expands the possibilities for recursive pathways beyond the modular or iterative synthesis of natural products and serves as a case study for understanding the challenges of building recursive pathways from nonrecursive enzymes. There exists the potential to design synthetic recursive pathways far beyond what nature has evolved.
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Analysis of the ketosynthase-chain length factor heterodimer from the fredericamycin polyketide synthase. ACTA ACUST UNITED AC 2011; 18:1021-31. [PMID: 21867917 DOI: 10.1016/j.chembiol.2011.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 05/01/2011] [Accepted: 05/03/2011] [Indexed: 11/24/2022]
Abstract
The pentadecaketide fredericamycin has the longest carbon chain backbone among polycyclic aromatic polyketide antibiotics whose biosynthetic genes have been sequenced. This backbone is synthesized by the bimodular fdm polyketide synthase (PKS). Here, we demonstrate that the bimodular fdm PKS as well as its elongation module alone synthesize undecaketides and dodecaketides. Thus, unlike other homologs, the fdm ketosynthase-chain length factor (KS-CLF) heterodimer does not exclusively control the backbone length of its natural product. Using sequence- and structure-based approaches, 48 CLF multiple mutants were engineered and analyzed. Unexpectedly, the I134F mutant was unable to turn over but could initiate and partially elongate the polyketide chain. This unprecedented mutant suggests that the KS-CLF heterodimer harbors an as yet uncharacterized chain termination mechanism. Together, our findings reveal fundamental mechanistic differences between the fdm PKS and its well-studied homologs.
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Cloning of the biosynthetic gene cluster for naphthoxanthene antibiotic FD-594 from Streptomyces sp. TA-0256. J Antibiot (Tokyo) 2010; 64:123-32. [DOI: 10.1038/ja.2010.145] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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