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Im JH, Oh S, Bae ES, Um S, Lee SK, Ban YH, Oh DC. Discovery and structure elucidation of glycosyl and 5-hydroxy migrastatins from dung beetle gut Kitasatospora sp. J Ind Microbiol Biotechnol 2023; 50:kuad046. [PMID: 38093455 PMCID: PMC10750973 DOI: 10.1093/jimb/kuad046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 12/12/2023] [Indexed: 12/27/2023]
Abstract
Two new macrocyclic secondary metabolites, glycosyl-migrastatin (1) and 5-hydroxy-migrastatin (2), were isolated from a gut bacterium Kitasatospora sp. JL24 in dung beetle Onthophagus lenzii. Based on a comprehensive analysis of the nuclear magnetic resonance (NMR), MS, and UV spectroscopic data, the planar structures of 1 and 2 were successfully identified as new derivatives of migrastatin. Compound 1 was the first glycosylated member of the migrastatin family. The absolute configuration of the sugar moiety was determined to be d-glucose through the analysis of coupling constants and ROESY correlations, followed by chemical derivatization and chromatographic comparison with authentic d- and l-glucose. Compound 2, identified as 5-hydroxy-migrastatin possessing an additional hydroxy group with a previously unreported chiral center, was assigned using Mosher's method through 19F NMR chemical shifts and confirmed with the modified Mosher's method. Genomic analysis of Kitasatospora sp. strain JL24 revealed a putative biosynthetic pathway involving an acyltransferase-less type I polyketide synthase biosynthetic gene cluster. ONE-SENTENCE SUMMARY Two secondary metabolites, glycosyl-migrastatin (1) and 5-hydroxy-migrastatin (2), were discovered from the gut bacterium Kitasatospora sp. JL24 in the dung beetle Onthophagus lenzii.
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Affiliation(s)
- Ji Hyeon Im
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Seoyoung Oh
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Eun Seo Bae
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Soohyun Um
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Sang Kook Lee
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Yeon Hee Ban
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Dong-Chan Oh
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
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2
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Lee B, Son S, Lee JK, Jang M, Heo KT, Ko SK, Park DJ, Park CS, Kim CJ, Ahn JS, Hwang BY, Jang JH, Hong YS. Isolation of new streptimidone derivatives, glutarimide antibiotics from Streptomyces sp. W3002 using LC-MS-guided screening. J Antibiot (Tokyo) 2019; 73:184-188. [PMID: 31853030 DOI: 10.1038/s41429-019-0264-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/19/2019] [Accepted: 11/27/2019] [Indexed: 11/09/2022]
Abstract
A LC-MS-guided screening led to the isolation of two new streptimidone derivatives (2 and 3) containing a glutarimide ring and two glutarimide ring-opened compounds (4 and 5) along with a known glutarimide-containing polyketide, streptimidone (1) from Streptomyces sp. W3002 strain. Their structures were elucidated by MS and NMR spectroscopic analyses and by comparison with data from the literature. Compound 2 is a non-hydroxylated analog at the C-5 position of streptimidone. The structure of 3 was determined as a streptimidone derivative possessing the α, β-unsaturated ketone moiety at positions C-5 and C-6. Compound 4 had similar chemical shifts and splitting patterns with 3, but the glutarimide ring is opened. Compound 5 closely resembles that of 4 with the only difference being the existence of an additional methoxy group instead of an amide group. Streptimidone (1) and 3 showed weak cytotoxic activity against three human cancer cell lines, respectively.
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Affiliation(s)
- Byeongsan Lee
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,College of Pharmacy, Chungbuk National University, Cheongju, 28160, Korea
| | - Sangkeun Son
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Jae Kyoung Lee
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Mina Jang
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea
| | - Kyung Taek Heo
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea
| | - Sung-Kyun Ko
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea
| | - Dong-Jin Park
- Industrial Bio-materials Research Center, KRIBB, Daejeon, 34141, Korea
| | - Chan Sun Park
- Immunoregulatory Materials Research Center, KRIBB, Jeongeup, 56212, Korea
| | - Chang-Jin Kim
- KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea.,Industrial Bio-materials Research Center, KRIBB, Daejeon, 34141, Korea
| | - Jong Seog Ahn
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Bang Yeon Hwang
- College of Pharmacy, Chungbuk National University, Cheongju, 28160, Korea
| | - Jae-Hyuk Jang
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea
| | - Young-Soo Hong
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea. .,KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, 34141, Korea.
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3
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Zhang D, Yi W, Ge H, Zhang Z, Wu B. Bioactive Streptoglutarimides A-J from the Marine-Derived Streptomyces sp. ZZ741. JOURNAL OF NATURAL PRODUCTS 2019; 82:2800-2808. [PMID: 31584271 DOI: 10.1021/acs.jnatprod.9b00481] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The new streptoglutarimides A-J (1-10) and the known streptovitacin A (11) were isolated from a marine-derived actinomycete, Streptomyces sp. ZZ741. Structures of the isolated compounds were elucidated based on their HRESIMS data, extensive NMR spectroscopic analyses, ECD calculations, Mosher's method, and a single-crystal X-ray diffraction experiment. Streptoglutarimide H (8) and streptovitacin A (11) showed potent antiproliferative activity against human glioma U87MG and U251 cells with IC50 values of 1.5-3.8 μM for 8 and 0.05-0.22 μM for 11. All isolated compounds exhibited antimicrobial activity with MIC values of 9-11 μg/mL against methicillin-resistant Staphylococcus aureus, 8-12 μg/mL against Escherichia coli, and 8-20 μg/mL against Candida albicans.
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Affiliation(s)
- Di Zhang
- Ocean College, Zhoushan Campus , Zhejiang University , Zhoushan 316021 , People's Republic of China
| | - Wenwen Yi
- Ocean College, Zhoushan Campus , Zhejiang University , Zhoushan 316021 , People's Republic of China
| | - Hengju Ge
- Ocean College, Zhoushan Campus , Zhejiang University , Zhoushan 316021 , People's Republic of China
| | - Zhizhen Zhang
- Ocean College, Zhoushan Campus , Zhejiang University , Zhoushan 316021 , People's Republic of China
| | - Bin Wu
- Ocean College, Zhoushan Campus , Zhejiang University , Zhoushan 316021 , People's Republic of China
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4
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Rudolf JD, Chang CY, Ma M, Shen B. Cytochromes P450 for natural product biosynthesis in Streptomyces: sequence, structure, and function. Nat Prod Rep 2017; 34:1141-1172. [PMID: 28758170 PMCID: PMC5585785 DOI: 10.1039/c7np00034k] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Covering: up to January 2017Cytochrome P450 enzymes (P450s) are some of the most exquisite and versatile biocatalysts found in nature. In addition to their well-known roles in steroid biosynthesis and drug metabolism in humans, P450s are key players in natural product biosynthetic pathways. Natural products, the most chemically and structurally diverse small molecules known, require an extensive collection of P450s to accept and functionalize their unique scaffolds. In this review, we survey the current catalytic landscape of P450s within the Streptomyces genus, one of the most prolific producers of natural products, and comprehensively summarize the functionally characterized P450s from Streptomyces. A sequence similarity network of >8500 P450s revealed insights into the sequence-function relationships of these oxygen-dependent metalloenzymes. Although only ∼2.4% and <0.4% of streptomycete P450s have been functionally and structurally characterized, respectively, the study of streptomycete P450s involved in the biosynthesis of natural products has revealed their diverse roles in nature, expanded their catalytic repertoire, created structural and mechanistic paradigms, and exposed their potential for biomedical and biotechnological applications. Continued study of these remarkable enzymes will undoubtedly expose their true complement of chemical and biological capabilities.
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Affiliation(s)
- Jeffrey D Rudolf
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
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5
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Zhang B, Xu Z, Teng Q, Pan G, Ma M, Shen B. A Long-Range Acting Dehydratase Domain as the Missing Link for C17-Dehydration in Iso-Migrastatin Biosynthesis. Angew Chem Int Ed Engl 2017; 56:7247-7251. [PMID: 28464455 DOI: 10.1002/anie.201703588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 11/05/2022]
Abstract
The dehydratase domains (DHs) of the iso-migrastatin (iso-MGS) polyketide synthase (PKS) were investigated by systematic inactivation of the DHs in module-6, -9, -10 of MgsF (i.e., DH6, DH9, DH10) and module-11 of MgsG (i.e., DH11) in vivo, followed by structural characterization of the metabolites accumulated by the mutants, and biochemical characterization of DH10 in vitro, using polyketide substrate mimics with varying chain lengths. These studies allowed us to assign the functions for all four DHs, identifying DH10 as the dedicated dehydratase that catalyzes the dehydration of the C17 hydroxy group during iso-MGS biosynthesis. In contrast to canonical DHs that catalyze dehydration of the β-hydroxy groups of the nascent polyketide intermediates, DH10 acts in a long-range manner that is unprecedented for type I PKSs, a novel dehydration mechanism that could be exploited for polyketide structural diversity by combinatorial biosynthesis and synthetic biology.
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Affiliation(s)
- Bo Zhang
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Zhengren Xu
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Qihui Teng
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Guohui Pan
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Ming Ma
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, 33458, USA.,Department of Molecular Medicine, Natural Products Library Initiative, The Scripps Research Institute, Jupiter, FL, 33458, USA
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6
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Zhang B, Xu Z, Teng Q, Pan G, Ma M, Shen B. A Long-Range Acting Dehydratase Domain as the Missing Link for C17-Dehydration in Iso-Migrastatin Biosynthesis. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703588] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Bo Zhang
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
| | - Zhengren Xu
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
| | - Qihui Teng
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
| | - Guohui Pan
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
| | - Ming Ma
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
| | - Ben Shen
- Department of Chemistry; The Scripps Research Institute; Jupiter FL 33458 USA
- Department of Molecular Medicine, Natural Products Library Initiative; The Scripps Research Institute; Jupiter FL 33458 USA
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7
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Brzozowski RS, Wuest WM. Twelve-membered macrolactones: privileged scaffolds for the development of new therapeutics. Chem Biol Drug Des 2017; 89:169-191. [PMID: 27153932 DOI: 10.1111/cbdd.12783] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 12/15/2022]
Abstract
Natural products commonly produced as secondary metabolites of various plants and micro-organisms represent a diverse chemical space of compounds. The diversity of natural products makes them an attractive target for interrogation by both chemists and biologists alike. Indeed, the study of 12-membered macrolactones has already led to the discovery of lead drug compounds and new biological targets, which has motivated the development of diverted total synthetic routes to libraries of analogs. This review explores the discovery, biological characterization, and synthesis of several 12-membered macrolactones, exploiting examples that underscore their importance in the drug discovery field. It is our hope that this review will motivate further interest in this class of natural products, a group of molecules that we think merit the classification of 'privileged scaffolds' within the medicinal chemistry community, to further investigate and develop novel compounds with promising bioactivity.
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Affiliation(s)
| | - William M Wuest
- Department of Chemistry, Temple University, Philadelphia, PA, USA
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8
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Sumimoto S, Iwasaki A, Ohno O, Sueyoshi K, Teruya T, Suenaga K. Kanamienamide, an Enamide with an Enol Ether from the Marine Cyanobacterium Moorea bouillonii. Org Lett 2016; 18:4884-4887. [DOI: 10.1021/acs.orglett.6b02364] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shimpei Sumimoto
- Department
of Chemistry, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Arihiro Iwasaki
- Department
of Chemistry, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Osamu Ohno
- Department
of Chemistry and Life Science, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
| | - Kosuke Sueyoshi
- Faculty
of Education, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | - Toshiaki Teruya
- Faculty
of Education, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | - Kiyotake Suenaga
- Department
of Chemistry, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
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9
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Molecular Genetic Characterization of an Anthrabenzoxocinones Gene Cluster in Streptomyces Sp. FJS31-2 for the Biosynthesis of BE-24566B and Zunyimycin Ale. Molecules 2016; 21:molecules21060711. [PMID: 27248985 PMCID: PMC6273070 DOI: 10.3390/molecules21060711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/08/2016] [Accepted: 05/18/2016] [Indexed: 12/05/2022] Open
Abstract
Genome mining is an effective tool used to discover novel natural products from actinomycetes. Genome sequence analysis of Streptomyces sp. FJS31-2 revealed the presence of one putative type II polyketide gene cluster (ABX), which may correspond to type II polyketide products including BE-24566B and its chloro-derivatives. The addition of natural humus acid successfully activated the biosynthsis of the abx gene cluster. BE-24566B and its chloro-derivatives, named zunyimycin A, were also detected. The targeted deletion of the polyketide skeleton synthesis genes such as abxp, abxk, and abxs was performed in the wild strain to identify the gene cluster for BE-24566B biosynthesis.
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10
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Helfrich EJN, Piel J. Biosynthesis of polyketides by trans-AT polyketide synthases. Nat Prod Rep 2016; 33:231-316. [DOI: 10.1039/c5np00125k] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This review discusses the biosynthesis of natural products that are generated bytrans-AT polyketide synthases, a family of catalytically versatile enzymes that represents one of the major group of proteins involved in the production of bioactive polyketides.
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Affiliation(s)
- Eric J. N. Helfrich
- Institute of Microbiology
- Eidgenössische Technische Hochschule (ETH) Zurich
- 8093 Zurich
- Switzerland
| | - Jörn Piel
- Institute of Microbiology
- Eidgenössische Technische Hochschule (ETH) Zurich
- 8093 Zurich
- Switzerland
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11
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Larsen BJ, Sun Z, Lachacz E, Khomutnyk Y, Soellner MB, Nagorny P. Synthesis and Biological Evaluation of Lactimidomycin and Its Analogues. Chemistry 2015; 21:19159-67. [PMID: 26577990 DOI: 10.1002/chem.201503527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Indexed: 02/06/2023]
Abstract
The studies culminating in the total synthesis of the glutarimide-containing eukaryote translation elongation inhibitor lactimidomycin are described. The optimized synthetic route features a Zn(II)-mediated intramolecular Horner-Wadsworth-Emmons (HWE) reaction resulting in a highly stereoselective formation of the strained 12-membered macrolactone of lactimidomycin on a 423 mg scale. The presence of the E,Z-diene functionality was found to be key for effective macrocyclizations as a complete removal of these unsaturation units resulted in exclusive formation of the dimer rather than monocyclic enoate. The synthetic route features a late-stage installation of the glutarimide functionality via an asymmetric catalytic Mukaiyama aldol reaction, which allows for a quick generation of lactimidomycin homolog 55 containing two additional carbons in the glutarimide side chain. Similar to lactimidomycin, this analog was found to possess cytotoxicity against MDA-MB-231 breast cancer cells (GI50 =1-3 μM) using in vitro 2D and 3D assays. Although lactimidomycin was found to be the most potent compound in terms of anticancer activity, 55 as well as truncated analogues 50-52 lacking the glutarimide side-chain were found to be significantly less toxic against human mammary epithelial cells.
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Affiliation(s)
- Brian J Larsen
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Zhankui Sun
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Eric Lachacz
- Medicinal Chemistry Department, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065 (USA)
| | - Yaroslav Khomutnyk
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Matthew B Soellner
- Medicinal Chemistry Department, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065 (USA).
| | - Pavel Nagorny
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA).
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12
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Seo JW, Ma M, Kwong T, Ju J, Lim SK, Jiang H, Lohman JR, Yang C, Cleveland J, Zazopoulos E, Farnet CM, Shen B. Comparative characterization of the lactimidomycin and iso-migrastatin biosynthetic machineries revealing unusual features for acyltransferase-less type I polyketide synthases and providing an opportunity to engineer new analogues. Biochemistry 2014; 53:7854-65. [PMID: 25405956 PMCID: PMC4270375 DOI: 10.1021/bi501396v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Lactimidomycin (LTM, 1) and iso-migrastatin (iso-MGS, 2) belong to the glutarimide-containing polyketide family of natural products. We previously cloned and characterized the mgs biosynthetic gene cluster from Streptomyces platensis NRRL 18993. The iso-MGS biosynthetic machinery featured an acyltransferase (AT)-less type I polyketide synthase (PKS) and three tailoring enzymes (MgsIJK). We now report cloning and characterization of the ltm biosynthetic gene cluster from Streptomyces amphibiosporus ATCC 53964, which consists of nine genes that encode an AT-less type I PKS (LtmBCDEFGHL) and one tailoring enzyme (LtmK). Inactivation of ltmE or ltmH afforded the mutant strain SB15001 or SB15002, respectively, that abolished the production of 1, as well as the three cometabolites 8,9-dihydro-LTM (14), 8,9-dihydro-8S-hydroxy-LTM (15), and 8,9-dihydro-9R-hydroxy-LTM (13). Inactivation of ltmK yielded the mutant strain SB15003 that abolished the production of 1, 13, and 15 but led to the accumulation of 14. Complementation of the ΔltmK mutation in SB15003 by expressing ltmK in trans restored the production of 1, as well as that of 13 and 15. These results support the model for 1 biosynthesis, featuring an AT-less type I PKS that synthesizes 14 as the nascent polyketide intermediate and a cytochrome P450 desaturase that converts 14 to 1, with 13 and 15 as minor cometabolites. Comparative analysis of the LTM and iso-MGS AT-less type I PKSs revealed several unusual features that deviate from those of the collinear type I PKS model. Exploitation of the tailoring enzymes for 1 and 2 biosynthesis afforded two analogues, 8,9-dihydro-8R-hydroxy-LTM (16) and 8,9-dihydro-8R-methoxy-LTM (17), that provided new insights into the structure-activity relationship of 1 and 2. While 12-membered macrolides, featuring a combination of a hydroxyl group at C-17 and a double bond at C-8 and C-9 as found in 1, exhibit the most potent activity, analogues with a single hydroxyl or methoxy group at C-8 or C-9 retain most of the activity whereas analogues with double substitutions at C-8 and C-9 lose significant activity.
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Affiliation(s)
- Jeong-Woo Seo
- Division of Pharmaceutical Sciences, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
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13
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Affiliation(s)
- Tomohiro Nagasawa
- Laboratory of Applied Bioorganic Chemistry, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
| | - Shigefumi Kuwahara
- Laboratory of Applied Bioorganic Chemistry, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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14
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