1
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Poudel PB, Dhakal D, Lee JC, Sohng JK. Functional characterization of a naphthalene-O-methyltransferase from Nocardia sp. CS682. Enzyme Microb Technol 2024; 172:110351. [PMID: 37939423 DOI: 10.1016/j.enzmictec.2023.110351] [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: 07/18/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/10/2023]
Abstract
Methylation plays important roles in biosynthesis, metabolism, signal transduction, detoxification, protein sorting and repair, and nucleic acid processing. Generally the methyltransferases transfer methyl groups in various natural products using S-adenosyl methionine (SAM) as a cofactor. In this study, we examined and functionally characterized ThnM3 (enzyme), by testing various substrates with different chemical structures. Among the tested substrates, 1,8-dihydroxynaphthalene was the best substrate for methylation. Whole-cell biotransformation was performed using the enzyme in engineered Escherichia coli to produce 8-methoxynaphthalene-1-ol, and 1,8-dimethoxynaphthalene derivatives of 1,8-dihydroxynaphthalene. The products were confirmed using high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopic analyses. Therefore, this study is the first to amplify, express the thnM3 (gene), and functionally characterize theThnM3, which exhibits the regioselective modifications of 1,8-dihydroxynaphthalene.
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Affiliation(s)
- Purna Bahadur Poudel
- Institute of Biomolecule Reconstruction (iBR), Department of Life Science and Biochemical Engineering, Sun Moon University, 70 Sun Moon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, South Korea
| | - Dipesh Dhakal
- Institute of Biomolecule Reconstruction (iBR), Department of Life Science and Biochemical Engineering, Sun Moon University, 70 Sun Moon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, South Korea
| | - Jong Cheol Lee
- Department of Pharmaceutical Engineering and Biotechnology, Sun Moon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, South Korea
| | - Jae Kyung Sohng
- Institute of Biomolecule Reconstruction (iBR), Department of Life Science and Biochemical Engineering, Sun Moon University, 70 Sun Moon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, South Korea; Department of Pharmaceutical Engineering and Biotechnology, Sun Moon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam 31460, South Korea.
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2
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Zou ZR, Zhang K, Han TY, Zhou Q, Lin S, Hou XF, Tang GL. Two-enzyme cascade catalyzed trideuteromethylative modification of natural products. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.133137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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3
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Han T, Zhang K, Tang G, Zhou Q. Characterizing
Post‐PKS
Modifications of
16‐Demethyl
‐rifamycin Revealed Two Dehydrogenases Diverting the Aromatization Mode of Naphthalenic Ring in Ansamycin Biosynthesis. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202200098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ting‐Yan Han
- State Key Laboratory of Bio‐organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Kai Zhang
- State Key Laboratory of Bio‐organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Gong‐Li Tang
- State Key Laboratory of Bio‐organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
- School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sublane Xiangshan Hangzhou 310024 China
| | - Qiang Zhou
- State Key Laboratory of Bio‐organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
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4
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Rifamycin antibiotics and the mechanisms of their failure. J Antibiot (Tokyo) 2021; 74:786-798. [PMID: 34400805 DOI: 10.1038/s41429-021-00462-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/21/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023]
Abstract
Rifamycins are a class of antibiotics that were first discovered in 1957 and are known for their use in treating tuberculosis (TB). Rifamycins exhibit bactericidal activity against many Gram-positive and Gram-negative bacteria by inhibiting RNA polymerase (RNAP); however, resistance is prevalent and the mechanisms range from primary target modification and antibiotic inactivation to cytoplasmic exclusion. Further, phenotypic resistance, in which only a subpopulation of bacteria grow in concentrations exceeding their minimum inhibitory concentration, and tolerance, which is characterized by reduced rates of bacterial cell death, have been identified as additional causes of rifamycin failure. Here we summarize current understanding and recent developments regarding this critical antibiotic class.
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5
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Liu X, Liu Y, Lei C, Zhao G, Wang J. GlnR Dominates Rifamycin Biosynthesis by Activating the rif Cluster Genes Transcription Both Directly and Indirectly in Amycolatopsis mediterranei. Front Microbiol 2020; 11:319. [PMID: 32194530 PMCID: PMC7062684 DOI: 10.3389/fmicb.2020.00319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/13/2020] [Indexed: 12/22/2022] Open
Abstract
Because of the remarkable efficacy in treating mycobacterial infections, rifamycin and its derivatives are still first-line antimycobacterial drugs. It has been intensely studied to increase rifamycin yield from Amycolatopsis mediterranei, and nitrate is found to provide a stable and remarkable stimulating effect on the rifamycin production, a phenomenon known as "nitrate-stimulating effect (NSE)". Although the NSE has been widely used for the industrial production of rifamycin, its detailed molecular mechanism remains ill-defined. And our previous study has established that the global nitrogen regulator GlnR may participate in the NSE, but the underlying mechanism is still enigmatic. Here, we demonstrate that GlnR directly controls rifamycin biosynthesis in A. mediterranei and thus plays an essential role in the NSE. Firstly, GlnR specifically binds to the upstream region of rifZ, which leads us to uncover that rifZ has its own promoter. As RifZ is a pathway-specific activator for the whole rif cluster, GlnR indirectly upregulates the whole rif cluster transcription by directly activating the rifZ expression. Secondly, GlnR specifically binds to the upstream region of rifK, which is also characterized to have its own promoter. It is well-known that RifK is a 3-amino-5-hydroxybenzoic acid (AHBA, the starter unit of rifamycin) synthase, thus GlnR can promote the supply of the rifamycin precursor by directly activating the rifK transcription. Notably, GlnR and RifZ independently activate the rifK transcription through binding to different sites in rifK promoter region, which suggests that the cells have a sophisticated regulatory mechanism to control the AHBA biosynthesis. Collectively, this study reveals that GlnR activates the rif cluster transcription in both direct (for rifZ and rifK) and indirect (for the whole rif cluster) manners, which well interprets the phenomenon that the NSE doesn't occur in the glnR null mutant. Furthermore, this study deepens our understanding about the molecular mechanism of the NSE.
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Affiliation(s)
- Xinqiang Liu
- CAS Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yuanyuan Liu
- Shanghai Tolo Biotechnology Company Limited, Shanghai, China
| | - Chao Lei
- CAS Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Guoping Zhao
- CAS Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jin Wang
- College of Life Sciences, Shanghai Normal University, Shanghai, China
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6
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Li X, Wu X, Zhu J, Shen Y. Amexanthomycins A–J, pentangular polyphenols produced by Amycolatopsis mediterranei S699∆rifA. Appl Microbiol Biotechnol 2017; 102:689-702. [DOI: 10.1007/s00253-017-8648-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 11/08/2017] [Accepted: 11/12/2017] [Indexed: 10/18/2022]
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7
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Kumari R, Singh P, Lal R. Genetics and Genomics of the Genus Amycolatopsis. Indian J Microbiol 2016; 56:233-46. [PMID: 27407288 PMCID: PMC4920768 DOI: 10.1007/s12088-016-0590-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/23/2016] [Indexed: 02/06/2023] Open
Abstract
Actinobacteria are gram-positive filamentous bacteria which contains some of the most deadly human pathogens (Mycobacterium tuberculosis, M. leprae, Corynebacterium diphtheriae, Nocardia farcinica), plant pathogens (Streptomyces scabies, Leifsonia xyli) along with organisms that produces antibiotic (Streptomycetes, Amycolatopsis, Salinospora). Interestingly, these bacteria are equipped with an extraordinary capability of producing antibiotics and other metabolites which have medicinal properties. With the advent of inexpensive genome sequencing techniques and their clinical importance, many genomes of Actinobacteria have been successfully sequenced. These days, with the constant increasing number of drug-resistant bacteria, the urgent need for discovering new antibiotics has emerged as a major scientific challenge. And, unfortunately the traditional method of screening bacterial strains for the production of antibiotics has decreased leading to a paradigm shift in the planning and execution of discovery of novel biosynthetic gene clusters via genome mining process. The entire focus has shifted to the evaluation of genetic capacity of organisms for metabolite production and activation of cryptic gene clusters. This has been made possible only due to the availability of genome sequencing and has been augmented by genomic studies and new biotechnological approaches. Through this article, we present the analysis of the genomes of species belonging to the genus Amycolatopsis, sequenced till date with a focus on completely sequenced genomes and their application for further studies.
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Affiliation(s)
- Rashmi Kumari
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
| | - Priya Singh
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
| | - Rup Lal
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
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8
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Nigam A, Almabruk KH, Saxena A, Yang J, Mukherjee U, Kaur H, Kohli P, Kumari R, Singh P, Zakharov LN, Singh Y, Mahmud T, Lal R. Modification of rifamycin polyketide backbone leads to improved drug activity against rifampicin-resistant Mycobacterium tuberculosis. J Biol Chem 2015; 289:21142-52. [PMID: 24923585 DOI: 10.1074/jbc.m114.572636] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rifamycin B, a product of Amycolatopsis mediterranei S699, is the precursor of clinically used antibiotics that are effective against tuberculosis, leprosy, and AIDS-related mycobacterial infections. However, prolonged usage of these antibiotics has resulted in the emergence of rifamycin-resistant strains of Mycobacterium tuberculosis. As part of our effort to generate better analogs of rifamycin, we substituted the acyltransferase domain of module 6 of rifamycin polyketide synthase with that of module 2 of rapamycin polyketide synthase. The resulting mutants (rifAT6::rapAT2) of A. mediterranei S699 produced new rifamycin analogs, 24-desmethylrifamycin B and 24-desmethylrifamycin SV, which contained modification in the polyketide backbone. 24-Desmethylrifamycin B was then converted to 24-desmethylrifamycin S, whose structure was confirmed by MS, NMR, and X-ray crystallography. Subsequently, 24-desmethylrifamycin S was converted to 24-desmethylrifampicin, which showed excellent antibacterial activity against several rifampicin-resistant M. tuberculosis strains.
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9
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Yuan H, Zhao W, Zhong Y, Wang J, Qin Z, Ding X, Zhao GP. Two genes, rif15 and rif16, of the rifamycin biosynthetic gene cluster in Amycolatopsis mediterranei likely encode a transketolase and a P450 monooxygenase, respectively, both essential for the conversion of rifamycin SV into B. Acta Biochim Biophys Sin (Shanghai) 2011; 43:948-56. [PMID: 21986914 DOI: 10.1093/abbs/gmr091] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Amycolatopsis mediterranei produces an important antibiotic rifamycin, the biosynthesis of which involves many unusual modifications. Previous work suggested a putative P450 enzyme encoded by rif16 within the rifamycin biosynthetic gene cluster (rif) was required for the conversion of the intermediate rifamycin SV into the end product rifamycin B. In this study, we genetically proved that a putative transketolase encoded by rif15 is another essential enzyme for this conversion. Expression of merely rif15 and rif16 in a rif cluster null mutant of A. mediterranei U32 was able to convert rifamycin SV into B. However, this Rif15- and Rif16-mediated conversion was only detected in intact cells of A. meidterranei, but not in Streptomyce coelicolor or Mycobacterium smegmatis, suggesting that yet-characterized gene(s) in A. mediterranei other than those encoded by the rif cluster should be involved in this process.
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Affiliation(s)
- Hua Yuan
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
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10
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Yin M, Lu T, Zhao LX, Chen Y, Huang SX, Lohman JR, Xu LH, Jiang CL, Shen B. The missing C-17 O-methyltransferase in geldanamycin biosynthesis. Org Lett 2011; 13:3726-9. [PMID: 21682254 DOI: 10.1021/ol201383w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The biosynthetic gene clusters for the Hsp90 inhibitor geldanamycin (GDM, 1) have been cloned previously from three different Streptomyces strains, but the gene encoding the C-17 O-methyltransferase remains unknown. The cloning and sequencing of a new GDM biosynthetic gene cluster from Streptomyces autolyticus CGMCC 0516 was reported, identifying the gdmMT gene that encodes the missing C-17 O-methyltransferase for 1 biosynthesis.
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Affiliation(s)
- Min Yin
- Yunnan Institute of Microbiology, Yunnan University, Kunming, Yunnan 650091, China
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11
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Wu Y, Kang Q, Shang G, Spiteller P, Carroll B, Yu TW, Su W, Bai L, Floss HG. N-methylation of the amide bond by methyltransferase asm10 in ansamitocin biosynthesis. Chembiochem 2011; 12:1759-66. [PMID: 21681880 DOI: 10.1002/cbic.201100062] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Indexed: 11/07/2022]
Abstract
Ansamitocins are potent antitumor agents produced by Actinosynnema pretiosum. As deduced from their structures, an N-methylation on the amide bond is required among the various modifications. The protein encoded by asm10 belongs to the SAM-dependent methyltransferase family. Through gene inactivation and complementation, asm10 was proved to be responsible for the N-methylation of ansamitocins. Asm10 is a 33.0 kDa monomer, as determined by gel filtration. By using N-desmethyl-ansamitocin P-3 as substrate, the optimal temperature and pH for Asm10 catalysis were determined to be 32 °C and 10.0, respectively. Asm10 also showed broad substrate flexibility toward other N-desmethyl-ansamycins and synthetic indolin-2-ones. Through site-directed mutagenesis, Asp154 and Leu155 of Asm10 were confirmed to be essential for its catalysis, possibly through the binding of SAM. The characterization of this unique N-methyltransferase has enriched the toolbox for engineering N-methylated derivatives from both natural and synthetic compounds; this will allow known potential drugs to be modified.
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Affiliation(s)
- Yingying Wu
- State Key Laboratory of Stress Cell Biology and School of Life Sciences, Xiamen University, Xiamen 361005, China
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12
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Wilson MC, Gulder TAM, Mahmud T, Moore BS. Shared biosynthesis of the saliniketals and rifamycins in Salinispora arenicola is controlled by the sare1259-encoded cytochrome P450. J Am Chem Soc 2011; 132:12757-65. [PMID: 20726561 DOI: 10.1021/ja105891a] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Saliniketals A and B are unusual polyketides from the marine actinomycete Salinispora arenicola that inhibit ornithine decarboxylase induction. The structural similarities between the saliniketals and the ansa chain of the potent rifamycin antibiotics, which co-occur in the fermentation broth, suggest a common origin between the two compound classes. Using PCR-directed mutagenesis, chemical complementation studies, and stable isotope feeding experiments, we showed that the saliniketals are byproducts of the rifamycin biosynthetic pathway diverging at the stage of 34a-deoxyrifamycin W. Our results suggest that a single enzyme, the cytochrome P450 monooxygenase encoded by sare1259, catalyzes multiple oxidative rearrangement reactions on 34a-deoxyrifamyin W to yield both the saliniketal and rifamycin structural classes.
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Affiliation(s)
- Micheal C Wilson
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204, USA
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13
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Olano C, Méndez C, Salas JA. Post-PKS tailoring steps in natural product-producing actinomycetes from the perspective of combinatorial biosynthesis. Nat Prod Rep 2010; 27:571-616. [DOI: 10.1039/b911956f] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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14
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Singh S, McCoy JG, Zhang C, Bingman CA, Phillips GN, Thorson JS. Structure and mechanism of the rebeccamycin sugar 4'-O-methyltransferase RebM. J Biol Chem 2008; 283:22628-36. [PMID: 18502766 PMCID: PMC2504894 DOI: 10.1074/jbc.m800503200] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 03/11/2008] [Indexed: 11/06/2022] Open
Abstract
The 2.65-angstroms crystal structure of the rebeccamycin 4'-O-methyltransferase RebM in complex with S-adenosyl-l-homocysteine revealed RebM to adopt a typical S-adenosylmethionine-binding fold of small molecule O-methyltransferases (O-MTases) and display a weak dimerization domain unique to MTases. Using this structure as a basis, the RebM substrate binding model implicated a predominance of nonspecific hydrophobic interactions consistent with the reported ability of RebM to methylate a wide range of indolocarbazole surrogates. This model also illuminated the three putative RebM catalytic residues (His140/141 and Asp166) subsequently found to be highly conserved among sequence-related natural product O-MTases from GC-rich bacteria. Interrogation of these residues via site-directed mutagenesis in RebM demonstrated His140 and Asp166 to be most important for catalysis. This study reveals RebM to be a member of the general acid/base-dependent O-MTases and, as the first crystal structure for a sugar O-MTase, may also present a template toward the future engineering of natural product MTases for combinatorial applications.
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Affiliation(s)
- Shanteri Singh
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, USA
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15
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Luo Y, Lin S, Zhang J, Cooke HA, Bruner SD, Shen B. Regiospecific O-methylation of naphthoic acids catalyzed by NcsB1, an O-methyltransferase involved in the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin. J Biol Chem 2008; 283:14694-702. [PMID: 18387946 DOI: 10.1074/jbc.m802206200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Neocarzinostatin, a clinical anticancer drug, is the archetypal member of the chromoprotein family of enediyne antitumor antibiotics that are composed of a nonprotein chromophore and an apoprotein. The neocarzinostatin chromophore consists of a nine-membered enediyne core, a deoxyaminosugar, and a naphthoic acid moiety. We have previously cloned and sequenced the neocarzinostatin biosynthetic gene cluster and proposed that the biosynthesis of the naphthoic acid moiety and its incorporation into the neocarzinostatin chromophore are catalyzed by five enzymes NcsB, NcsB1, NcsB2, NcsB3, and NcsB4. Here we report the biochemical characterization of NcsB1, unveiling that: (i) NcsB1 is an S-adenosyl-L-methionine-dependent O-methyltransferase; (ii) NcsB1 catalyzes regiospecific methylation at the 7-hydroxy group of its native substrate, 2,7-dihydroxy-5-methyl-1-naphthoic acid; (iii) NcsB1 also recognizes other dihydroxynaphthoic acids as substrates and catalyzes regiospecific O-methylation; and (iv) the carboxylate and its ortho-hydroxy groups of the substrate appear to be crucial for NcsB1 substrate recognition and binding, and O-methylation takes place only at the free hydroxy group of these dihydroxynaphthoic acids. These findings establish that NcsB1 catalyzes the third step in the biosynthesis of the naphthoic acid moiety of the neocarzinostatin chromophore and further support the early proposal for the biosynthesis of the naphthoic acid and its incorporation into the neocarzinostatin chromophore with free naphthoic acids serving as intermediates. NcsB1 represents another opportunity that can now be exploited to produce novel neocarzinostatin analogs by engineering neocarzinostatin biosynthesis or applying directed biosynthesis strategies.
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Affiliation(s)
- Yinggang Luo
- Division of Pharmaceutical Sciences, University of Wisconsin National Cooperative Drug Discovery Group, Department of Chemistry, University of Wisconsin, Madison, WI 53705, USA
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16
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Sitachitta N, Lopanik NB, Mao Y, Sherman DH. Analysis of a parallel branch in the mitomycin biosynthetic pathway involving the mitN-encoded aziridine N-methyltransferase. J Biol Chem 2007; 282:20941-7. [PMID: 17507379 DOI: 10.1074/jbc.m702456200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitomycin C is a natural product with potent alkylating activity, and it is an important anticancer drug and antibiotic. mitN, one of three genes with high similarity to methyltransferases, is located within the mitomycin biosynthetic gene cluster. An inframe deletion in mitN of the mitomycin biosynthetic pathway was generated in Streptomyces lavendulae to produce the DHS5373 mutant strain. Investigation of DHS5373 revealed continued production of mitomycin A and mitomycin C in addition to the accumulation of a new mitomycin analog, 9-epi-mitomycin C. The mitN gene was overexpressed in Escherichia coli, and the histidine-tagged protein (MitN) was purified to homogeneity. Reaction of 9-epi-mitomycin C with MitN in the presence of S-adenosylmethionine yielded mitomycin E showing that the enzyme functions as an aziridine N-methyltransferase. Likewise, MitN was also shown to convert mitomycin A to mitomycin F under the same reaction conditions. We conclude that MitN plays an important role in a parallel biosynthetic pathway leading to the subclass of mitomycins with 9alpha-stereochemistry but is not involved directly in the biosynthesis of mitomycins A and C.
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Affiliation(s)
- Namthip Sitachitta
- Life Sciences Institute and Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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17
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Zhang C, Albermann C, Fu X, Peters NR, Chisholm JD, Zhang G, Gilbert EJ, Wang PG, Van Vranken DL, Thorson JS. RebG- and RebM-Catalyzed Indolocarbazole Diversification. Chembiochem 2006; 7:795-804. [PMID: 16575939 DOI: 10.1002/cbic.200500504] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Rebeccamycin and staurosporine represent two broad classes of indolocarbazole glycoside natural products with antitumor properties. Based upon previous sequence annotation and in vivo studies, rebG encodes for the rebeccamycin N-glucosyltransferase, and rebM for the requisite 4'-O-methyltransferase. In the current study, an efficient in vivo biotransformation system for RebG was established in both Streptomyces lividans and Escherichia coli. Bioconversion experiments revealed RebG to glucosylate a set of indolocarbazole surrogates, the products of which could be further modified by in vitro RebM-catalyzed 4'-O-methylation. Both RebG and RebM displayed substrate promiscuity, and evidence for a remarkable lack of RebG regioselectivity in the presence of asymmetric substrates is also provided. In the context of the created indolocarbazole analogues, cytotoxicity assays also highlight the importance of 4'-O-methylation for their biological activity.
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Affiliation(s)
- Changsheng Zhang
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, 777 Highland Avenue, Madison, WI 53705, USA
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18
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Xiong Y, Wu X, Mahmud T. A homologue of the Mycobacterium tuberculosis PapA5 protein, rif-orf20, is an acetyltransferase involved in the biosynthesis of antitubercular drug rifamycin B by Amycolatopsis mediterranei S699. Chembiochem 2006; 6:834-7. [PMID: 15791687 DOI: 10.1002/cbic.200400387] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yeping Xiong
- College of Pharmacy, Oregon State University, Corvallis, OR 97331-3507, USA
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19
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Xu J, Wan E, Kim CJ, Floss HG, Mahmud T. Identification of tailoring genes involved in the modification of the polyketide backbone of rifamycin B by Amycolatopsis mediterranei S699. MICROBIOLOGY-SGM 2005; 151:2515-2528. [PMID: 16079331 DOI: 10.1099/mic.0.28138-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rifamycin B biosynthesis by Amycolatopsis mediterranei S699 involves a number of unusual modification reactions in the formation of the unique polyketide backbone and decoration of the molecule. A number of genes believed to be involved in the tailoring of rifamycin B were investigated and the results confirmed that the formation of the naphthalene ring moiety of rifamycin takes place during the polyketide chain extension and is catalysed by Rif-Orf19, a 3-(3-hydroxyphenyl)propionate hydroxylase-like protein. The cytochrome P450-dependent monooxygenase encoded by rif-orf5 is required for the conversion of the Delta12, 29 olefinic bond in the polyketide backbone of rifamycin W into the ketal moiety of rifamycin B. Furthermore, Rif-Orf3 may be involved in the regulation of rifamycin B production, as its knock-out mutant produced about 40 % more rifamycin B than the wild-type. The work also revealed that many of the genes located in the cluster are not involved in rifamycin biosynthesis, but might be evolutionary remnants carried over from an ancestral lineage.
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Affiliation(s)
- Jun Xu
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - Eva Wan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97331-3507, USA
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - Chang-Joon Kim
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - Heinz G Floss
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97331-3507, USA
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
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Affiliation(s)
- Heinz G Floss
- Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700, USA
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Onwueme KC, Ferreras JA, Buglino J, Lima CD, Quadri LEN. Mycobacterial polyketide-associated proteins are acyltransferases: proof of principle with Mycobacterium tuberculosis PapA5. Proc Natl Acad Sci U S A 2004; 101:4608-13. [PMID: 15070765 PMCID: PMC384794 DOI: 10.1073/pnas.0306928101] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2003] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis (Mt) produces complex virulence-enhancing lipids with scaffolds consisting of phthiocerol and phthiodiolone dimycocerosate esters (PDIMs). Sequence analysis suggested that PapA5, a so-called polyketide-associated protein (Pap) encoded in the PDIM synthesis gene cluster, as well as PapA5 homologs found in Mt and other species, are a subfamily of acyltransferases. Studies with recombinant protein confirmed that PapA5 is an acyltransferase [corrected]. Deletion analysis in Mt demonstrated that papA5 is required for PDIM synthesis. We propose that PapA5 catalyzes diesterification of phthiocerol and phthiodiolone with mycocerosate. These studies present the functional characterization of a Pap and permit inferences regarding roles of other Paps in the synthesis of complex lipids, including the antibiotic rifamycin.
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Affiliation(s)
- Kenolisa C Onwueme
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
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