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Pei X, Lei Y, Zhang H. Transcriptional regulators of secondary metabolite biosynthesis in Streptomyces. World J Microbiol Biotechnol 2024; 40:156. [PMID: 38587708 DOI: 10.1007/s11274-024-03968-2] [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: 02/14/2024] [Accepted: 03/25/2024] [Indexed: 04/09/2024]
Abstract
In the post-genome era, great progress has been made in metabolic engineering using recombinant DNA technology to enhance the production of high-value products by Streptomyces. With the development of microbial genome sequencing techniques and bioinformatic tools, a growing number of secondary metabolite (SM) biosynthetic gene clusters in Streptomyces and their biosynthetic logics have been uncovered and elucidated. In order to increase our knowledge about transcriptional regulators in SM of Streptomyces, this review firstly makes a comprehensive summary of the characterized factors involved in enhancing SM production and awakening SM biosynthesis. Future perspectives on transcriptional regulator engineering for new SM biosynthesis by Streptomyces are also provided.
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Affiliation(s)
- Xinwei Pei
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Yunyun Lei
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Huawei Zhang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, 310014, China.
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2
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Qadri H, Haseeb Shah A, Mudasir Ahmad S, Alshehri B, Almilaibary A, Ahmad Mir M. Natural products and their semi-synthetic derivatives against antimicrobial-resistant human pathogenic bacteria and fungi. Saudi J Biol Sci 2022; 29:103376. [PMID: 35874656 PMCID: PMC9290337 DOI: 10.1016/j.sjbs.2022.103376] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/09/2022] [Accepted: 07/10/2022] [Indexed: 12/24/2022] Open
Abstract
COVID-19 pandemic has traumatized the entire world. During this outbreak, an upsurge in MDR-associated pathogenic microbial organisms has been recorded. The increasing human microbial diseases pose a severe danger to global human safety. The infectious microbes have developed multiple tolerance strategies to overcome the negative drug impacts. Several naturally occurring chemicals produced from bacteria, plants, animals, marine species, and other sources with antimicrobial characteristics have been reviewed. These compounds show promise in minimizing the globally increasing microbial diseases.
Human infectious diseases caused by various microbial pathogens, in general, impact a large population of individuals every year. These microbial diseases that spread quickly remain to be a big issue in various health-related domains and to withstand the negative drug impacts, the antimicrobial-resistant pathogenic microbial organisms (pathogenic bacteria and pathogenic fungi) have developed a variety of resistance processes against many antimicrobial drug classes. During the COVID-19 outbreak, there seems to be an upsurge in drug and multidrug resistant-associated pathogenic microbial species. The preponderance of existing antimicrobials isn’t completely effective, which limits their application in clinical settings. Several naturally occurring chemicals produced from bacteria, plants, animals, marine species, and other sources are now being studied for antimicrobial characteristics. These natural antimicrobial compounds extracted from different sources have been demonstrated to be effective against a variety of diseases, although plants remain the most abundant source. These compounds have shown promise in reducing the microbial diseases linked to the development of drug tolerance and resistance. This paper offers a detailed review of some of the most vital and promising natural compounds and their derivatives against various human infectious microbial organisms. The inhibitory action of different natural antimicrobial compounds, and their possible mechanism of antimicrobial action against a range of pathogenic fungal and bacterial organisms, is provided. The review will be useful in refining current antimicrobial (antifungal and antibacterial) medicines as well as establishing new treatment strategies to tackle the rising number of human bacterial and fungal-associated infections.
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Affiliation(s)
- Hafsa Qadri
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar 190006, India
| | - Abdul Haseeb Shah
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar 190006, India
| | | | - Bader Alshehri
- Department of Medical Laboratory Science, College of Applied Medical Sciences, Majmaah University, Majmaah 11952, Saudi Arabia
| | - Abdullah Almilaibary
- Department of Family & Community Medicine, Faculty of Medicine, Albaha University, Alaqiq 307501, Saudi Arabia
| | - Manzoor Ahmad Mir
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar 190006, India
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3
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Cho MK, Lee BT, Kim HU, Oh MK. Systems metabolic engineering of Streptomyces venezuelae for the enhanced production of pikromycin. Biotechnol Bioeng 2022; 119:2250-2260. [PMID: 35445397 DOI: 10.1002/bit.28114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/06/2022] [Accepted: 04/15/2022] [Indexed: 11/09/2022]
Abstract
Pikromycin is an important precursor of drugs, for example, erythromycin. Hence, systems metabolic engineering for the enhanced pikromycin production can contribute to the development of pikromycin-related drugs. In this study, metabolic genes in Streptomyces venezuelae were systematically engineered for the enhanced pikromycin production. For this, a genome-scale metabolic model of S. venezuelae was reconstructed and simulated, which led to the selection of 11 metabolic gene targets. These metabolic genes, including four overexpression targets and seven knockdown targets, were individually engineered first. Next, two overexpression targets and two knockdown targets were selected based on the 11 strains' production performances in order to engineer two to four of these genes together for the potential synergistic effects on the pikromycin production. As a result, the NM1 strain with AQF52_RS24510 (methenyltetrahydrofolate cyclohydrolase/methylenetetrahydrofolate dehydrogenase) overexpression and AQF52_RS30320 (sulfite reductase) knockdown showed the best production performance among all the 22 strains constructed in this study. Fed-batch fermentation of the NM1 strain produced 295.25 mg/L of pikromycin, by far the best production titer using the native producer S. venezuelae, to the best of our knowledge. The systems metabolic engineering strategy demonstrated herein can also be applied to the overproduction of other secondary metabolites using S. venezuelae. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Min Kyung Cho
- Department of Chemical and Biological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Byung Tae Lee
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyun Uk Kim
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Min-Kyu Oh
- Department of Chemical and Biological Engineering, Korea University, Seoul, 02841, Republic of Korea
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Nah HJ, Park J, Choi S, Kim ES. WblA, a global regulator of antibiotic biosynthesis in Streptomyces. J Ind Microbiol Biotechnol 2021; 48:6127318. [PMID: 33928363 PMCID: PMC9113171 DOI: 10.1093/jimb/kuab007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/10/2020] [Indexed: 12/14/2022]
Abstract
Streptomyces species are soil-dwelling bacteria that produce vast numbers of pharmaceutically valuable secondary metabolites (SMs), such as antibiotics, immunosuppressants, antiviral, and anticancer drugs. On the other hand, the biosynthesis of most SMs remains very low due to tightly controlled regulatory networks. Both global and pathway-specific regulators are involved in the regulation of a specific SM biosynthesis in various Streptomyces species. Over the past few decades, many of these regulators have been identified and new ones are still being discovered. Among them, a global regulator of SM biosynthesis named WblA was identified in several Streptomyces species. The identification and understanding of the WblAs have greatly contributed to increasing the productivity of several Streptomyces SMs. This review summarizes the characteristics and applications on WblAs reported to date, which were found in various Streptomyces species and other actinobacteria.
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Affiliation(s)
- Hee-Ju Nah
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Jihee Park
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Sisun Choi
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
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Xia H, Li X, Li Z, Zhan X, Mao X, Li Y. The Application of Regulatory Cascades in Streptomyces: Yield Enhancement and Metabolite Mining. Front Microbiol 2020; 11:406. [PMID: 32265866 PMCID: PMC7105598 DOI: 10.3389/fmicb.2020.00406] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/26/2020] [Indexed: 12/13/2022] Open
Abstract
Streptomyces is taken as an important resource for producing the most abundant antibiotics and other bio-active natural products, which have been widely used in pharmaceutical and agricultural areas. Usually they are biosynthesized through secondary metabolic pathways encoded by cluster situated genes. And these gene clusters are stringently regulated by interweaved transcriptional regulatory cascades. In the past decades, great advances have been made to elucidate the regulatory mechanisms involved in antibiotic production in Streptomyces. In this review, we summarized the recent advances on the regulatory cascades of antibiotic production in Streptomyces from the following four levels: the signals triggering the biosynthesis, the global regulators, the pathway-specific regulators and the feedback regulation. The production of antibiotic can be largely enhanced by rewiring the regulatory networks, such as overexpression of positive regulators, inactivation of repressors, fine-tuning of the feedback and ribosomal engineering in Streptomyces. The enormous amount of genomic sequencing data implies that the Streptomyces has potential to produce much more antibiotics for the great diversities and wide distributions of biosynthetic gene clusters in Streptomyces genomes. Most of these gene clusters are defined cryptic for unknown or undetectable natural products. In the synthetic biology era, activation of the cryptic gene clusters has been successfully achieved by manipulation of the regulatory genes. Chemical elicitors, rewiring regulatory gene and ribosomal engineering have been employed to crack the potential of cryptic gene clusters. These have been proposed as the most promising strategy to discover new antibiotics. For the complex of regulatory network in Streptomyces, we proposed that the discovery of new antibiotics and the optimization of industrial strains would be greatly promoted by further understanding the regulatory mechanism of antibiotic production.
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Affiliation(s)
- Haiyang Xia
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China
| | - Xiaofang Li
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China
| | - Zhangqun Li
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China
| | - Xinqiao Zhan
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China
| | - Xuming Mao
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China.,Institute of Pharmaceutical Biotechnology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yongquan Li
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, China.,Institute of Pharmaceutical Biotechnology, School of Medicine, Zhejiang University, Hangzhou, China
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Pham JV, Yilma MA, Feliz A, Majid MT, Maffetone N, Walker JR, Kim E, Cho HJ, Reynolds JM, Song MC, Park SR, Yoon YJ. A Review of the Microbial Production of Bioactive Natural Products and Biologics. Front Microbiol 2019; 10:1404. [PMID: 31281299 PMCID: PMC6596283 DOI: 10.3389/fmicb.2019.01404] [Citation(s) in RCA: 230] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/04/2019] [Indexed: 12/24/2022] Open
Abstract
A variety of organisms, such as bacteria, fungi, and plants, produce secondary metabolites, also known as natural products. Natural products have been a prolific source and an inspiration for numerous medical agents with widely divergent chemical structures and biological activities, including antimicrobial, immunosuppressive, anticancer, and anti-inflammatory activities, many of which have been developed as treatments and have potential therapeutic applications for human diseases. Aside from natural products, the recent development of recombinant DNA technology has sparked the development of a wide array of biopharmaceutical products, such as recombinant proteins, offering significant advances in treating a broad spectrum of medical illnesses and conditions. Herein, we will introduce the structures and diverse biological activities of natural products and recombinant proteins that have been exploited as valuable molecules in medicine, agriculture and insect control. In addition, we will explore past and ongoing efforts along with achievements in the development of robust and promising microorganisms as cell factories to produce biologically active molecules. Furthermore, we will review multi-disciplinary and comprehensive engineering approaches directed at improving yields of microbial production of natural products and proteins and generating novel molecules. Throughout this article, we will suggest ways in which microbial-derived biologically active molecular entities and their analogs could continue to inspire the development of new therapeutic agents in academia and industry.
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Affiliation(s)
- Janette V. Pham
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Mariamawit A. Yilma
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Adriana Feliz
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Murtadha T. Majid
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Nicholas Maffetone
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Jorge R. Walker
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Eunji Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, South Korea
| | - Hyo Je Cho
- School of Life Sciences and Biotechnology, Kyungpook National University, Daegu, South Korea
| | - Jared M. Reynolds
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
| | - Myoung Chong Song
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, South Korea
| | - Sung Ryeol Park
- Geisinger Commonwealth School of Medicine, Scranton, PA, United States
- Baruch S. Blumberg Institute, Doylestown, PA, United States
- Natural Products Discovery Institute, Doylestown, PA, United States
| | - Yeo Joon Yoon
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, South Korea
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Wei J, He L, Niu G. Regulation of antibiotic biosynthesis in actinomycetes: Perspectives and challenges. Synth Syst Biotechnol 2018; 3:229-235. [PMID: 30417136 PMCID: PMC6215055 DOI: 10.1016/j.synbio.2018.10.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/27/2018] [Accepted: 10/17/2018] [Indexed: 02/08/2023] Open
Abstract
Actinomycetes are the main sources of antibiotics. The onset and level of production of each antibiotic is subject to complex control by multi-level regulators. These regulators exert their functions at hierarchical levels. At the lower level, cluster-situated regulators (CSRs) directly control the transcription of neighboring genes within the gene cluster. Higher-level pleiotropic and global regulators exert their functions mainly through modulating the transcription of CSRs. Advances in understanding of the regulation of antibiotic biosynthesis in actinomycetes have inspired us to engineer these regulators for strain improvement and antibiotic discovery.
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Affiliation(s)
- Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Lang He
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China.,Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Guoqing Niu
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China.,Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
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Yi JS, Kim M, Kim EJ, Kim BG. Production of pikromycin using branched chain amino acid catabolism in Streptomyces venezuelae ATCC 15439. J Ind Microbiol Biotechnol 2018. [PMID: 29523997 DOI: 10.1007/s10295-018-2024-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Branched chain amino acids (BCAA) are catabolized into various acyl-CoA compounds, which are key precursors used in polyketide productions. Because of that, BCAA catabolism needs fine tuning of flux balances for enhancing the production of polyketide antibiotics. To enhance BCAA catabolism for pikromycin production in Streptomyces venezuelae ATCC 15439, three key enzymes of BCAA catabolism, 3-ketoacyl acyl carrier protein synthase III, acyl-CoA dehydrogenase, and branched chain α-keto acid dehydrogenase (BCDH) were manipulated. BCDH overexpression in the wild type strain resulted in 1.3 fold increase in pikromycin production compared to that of WT, resulting in total 25 mg/L of pikromycin. To further increase pikromycin production, methylmalonyl-CoA mutase linked to succinyl-CoA production was overexpressed along with BCDH. Overexpression of the two enzymes resulted in the highest titer of total macrolide production of 43 mg/L, which was about 2.2 fold increase compared to that of the WT. However, it accumulated and produced dehydroxylated forms of pikromycin and methymycin, including their derivatives as well. It indicated that activities of pikC, P450 monooxygenase, newly became a bottleneck in pikromycin synthesis.
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Affiliation(s)
- Jeong Sang Yi
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Minsuk Kim
- Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun-Jung Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea. .,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea. .,Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea. .,Interdisciplinary Program for Biochemical Engineering and Biotechnology, and Bioengineering Institute, Seoul National University, Seoul, 08826, Republic of Korea.
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Kallifidas D, Jiang G, Ding Y, Luesch H. Rational engineering of Streptomyces albus J1074 for the overexpression of secondary metabolite gene clusters. Microb Cell Fact 2018; 17:25. [PMID: 29454348 PMCID: PMC5816538 DOI: 10.1186/s12934-018-0874-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 02/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genome sequencing revealed that Streptomyces sp. can dedicate up to ~ 10% of their genomes for the biosynthesis of bioactive secondary metabolites. However, the majority of these biosynthetic gene clusters are only weakly expressed or not at all. Indeed, the biosynthesis of natural products is highly regulated through integrating multiple nutritional and environmental signals perceived by pleiotropic and pathway-specific transcriptional regulators. Although pathway-specific refactoring has been a proved, productive approach for the activation of individual gene clusters, the construction of a global super host strain by targeting pleiotropic-specific genes for the expression of multiple diverse gene clusters is an attractive approach. RESULTS Streptomyces albus J1074 is a gifted heterologous host. To further improve its secondary metabolite expression capability, we rationally engineered the host by targeting genes affecting NADPH availability, precursor flux, cell growth and biosynthetic gene transcriptional activation. These studies led to the activation of the native paulomycin pathway in engineered S. albus strains and importantly the upregulated expression of the heterologous actinorhodin gene cluster. CONCLUSIONS Rational engineering of Streptomyces albus J1074 yielded a series of mutants with improved capabilities for native and heterologous expression of secondary metabolite gene clusters.
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Affiliation(s)
- Dimitris Kallifidas
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610 USA
- Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610 USA
| | - Guangde Jiang
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610 USA
- Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610 USA
| | - Yousong Ding
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610 USA
- Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610 USA
| | - Hendrik Luesch
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610 USA
- Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610 USA
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Pyeon HR, Nah HJ, Kang SH, Choi SS, Kim ES. Heterologous expression of pikromycin biosynthetic gene cluster using Streptomyces artificial chromosome system. Microb Cell Fact 2017; 16:96. [PMID: 28569150 PMCID: PMC5452415 DOI: 10.1186/s12934-017-0708-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 05/18/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heterologous expression of biosynthetic gene clusters of natural microbial products has become an essential strategy for titer improvement and pathway engineering of various potentially-valuable natural products. A Streptomyces artificial chromosomal conjugation vector, pSBAC, was previously successfully applied for precise cloning and tandem integration of a large polyketide tautomycetin (TMC) biosynthetic gene cluster (Nah et al. in Microb Cell Fact 14(1):1, 2015), implying that this strategy could be employed to develop a custom overexpression scheme of natural product pathway clusters present in actinomycetes. RESULTS To validate the pSBAC system as a generally-applicable heterologous overexpression system for a large-sized polyketide biosynthetic gene cluster in Streptomyces, another model polyketide compound, the pikromycin biosynthetic gene cluster, was preciously cloned and heterologously expressed using the pSBAC system. A unique HindIII restriction site was precisely inserted at one of the border regions of the pikromycin biosynthetic gene cluster within the chromosome of Streptomyces venezuelae, followed by site-specific recombination of pSBAC into the flanking region of the pikromycin gene cluster. Unlike the previous cloning process, one HindIII site integration step was skipped through pSBAC modification. pPik001, a pSBAC containing the pikromycin biosynthetic gene cluster, was directly introduced into two heterologous hosts, Streptomyces lividans and Streptomyces coelicolor, resulting in the production of 10-deoxymethynolide, a major pikromycin derivative. When two entire pikromycin biosynthetic gene clusters were tandemly introduced into the S. lividans chromosome, overproduction of 10-deoxymethynolide and the presence of pikromycin, which was previously not detected, were both confirmed. Moreover, comparative qRT-PCR results confirmed that the transcription of pikromycin biosynthetic genes was significantly upregulated in S. lividans containing tandem clusters of pikromycin biosynthetic gene clusters. CONCLUSIONS The 60 kb pikromycin biosynthetic gene cluster was isolated in a single integration pSBAC vector. Introduction of the pikromycin biosynthetic gene cluster into the pikromycin non-producing strains resulted in higher pikromycin production. The utility of the pSBAC system as a precise cloning tool for large-sized biosynthetic gene clusters was verified through heterologous expression of the pikromycin biosynthetic gene cluster. Moreover, this pSBAC-driven heterologous expression strategy was confirmed to be an ideal approach for production of low and inconsistent natural products such as pikromycin in S. venezuelae, implying that this strategy could be employed for development of a custom overexpression scheme of natural product biosynthetic gene clusters in actinomycetes.
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Affiliation(s)
- Hye-Rim Pyeon
- Department of Biological Engineering, Inha University, Incheon, 402-751, South Korea
| | - Hee-Ju Nah
- Department of Biological Engineering, Inha University, Incheon, 402-751, South Korea
| | - Seung-Hoon Kang
- Department of Biological Engineering, Inha University, Incheon, 402-751, South Korea
| | - Si-Sun Choi
- Department of Biological Engineering, Inha University, Incheon, 402-751, South Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon, 402-751, South Korea.
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