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Zhou Q, Ning S, Luo Y. Coordinated regulation for nature products discovery and overproduction in Streptomyces. Synth Syst Biotechnol 2020; 5:49-58. [PMID: 32346621 PMCID: PMC7176746 DOI: 10.1016/j.synbio.2020.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/04/2020] [Accepted: 04/08/2020] [Indexed: 12/19/2022] Open
Abstract
Streptomyces is an important treasure trove for natural products discovery. In recent years, many scientists focused on the genetic modification and metabolic regulation of Streptomyces to obtain diverse bioactive compounds with high yields. This review summarized the commonly used regulatory strategies for natural products discovery and overproduction in Streptomyces from three main aspects, including regulator-related strategies, promoter engineering, as well as other strategies employing transposons, signal factors, or feedback regulations. It is expected that the metabolic regulation network of Streptomyces will be elucidated more comprehensively to shed light on natural products research in the future.
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Affiliation(s)
- Qun Zhou
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Shuqing Ning
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Yunzi Luo
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072, China
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Musiol-Kroll EM, Tocchetti A, Sosio M, Stegmann E. Challenges and advances in genetic manipulation of filamentous actinomycetes - the remarkable producers of specialized metabolites. Nat Prod Rep 2019; 36:1351-1369. [PMID: 31517370 DOI: 10.1039/c9np00029a] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Covering: up to February 2019Actinomycetes are Gram positive bacteria of the phylum Actinobacteria. These organisms are one of the most important sources of structurally diverse, clinically used antibiotics and other valuable bioactive products, as well as biotechnologically relevant enzymes. Most strains were discovered by their ability to produce a given molecule and were often poorly characterized, physiologically and genetically. The development of genetic methods for Streptomyces and related filamentous actinomycetes has led to the successful manipulation of antibiotic biosynthesis to attain structural modification of microbial metabolites that would have been inaccessible by chemical means and improved production yields. Moreover, genome mining reveals that actinomycete genomes contain multiple biosynthetic gene clusters (BGCs), however only a few of them are expressed under standard laboratory conditions, leading to the production of the respective compound(s). Thus, to access and activate the so-called "silent" BGCs, to improve their biosynthetic potential and to discover novel natural products methodologies for genetic manipulation are required. Although different methods have been applied for many actinomycete strains, genetic engineering is still remaining very challenging for some "underexplored" and poorly characterized actinomycetes. This review summarizes the strategies developed to overcome the obstacles to genetic manipulation of actinomycetes and allowing thereby rational genetic engineering of this industrially relevant group of microorganisms. At the end of this review we give some tips to researchers with limited or no previous experience in genetic manipulation of actinomycetes. The article covers the most relevant literature published until February 2019.
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Affiliation(s)
- Ewa M Musiol-Kroll
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Microbiology/Biotechnology, Auf der Morgenstelle 28, Tübingen, 72076, Germany.
| | | | | | - Evi Stegmann
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Microbiology/Biotechnology, Auf der Morgenstelle 28, Tübingen, 72076, Germany.
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RifZ (AMED_0655) Is a Pathway-Specific Regulator for Rifamycin Biosynthesis in Amycolatopsis mediterranei. Appl Environ Microbiol 2017; 83:AEM.03201-16. [PMID: 28159794 DOI: 10.1128/aem.03201-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 01/26/2017] [Indexed: 11/20/2022] Open
Abstract
Rifamycin and its derivatives are particularly effective against the pathogenic mycobacteria Mycobacterium tuberculosis and Mycobacterium leprae Although the biosynthetic pathway of rifamycin has been extensively studied in Amycolatopsis mediterranei, little is known about the regulation in rifamycin biosynthesis. Here, an in vivo transposon system was employed to identify genes involved in the regulation of rifamycin production in A. mediterranei U32. In total, nine rifamycin-deficient mutants were isolated, among which three mutants had the transposon inserted in AMED_0655 (rifZ, encoding a LuxR family regulator). The rifZ gene was further knocked out via homologous recombination, and the transcription of genes in the rifamycin biosynthetic gene cluster (rif cluster) was remarkably reduced in the rifZ null mutant. Based on the cotranscription assay results, genes within the rif cluster were grouped into 10 operons, sharing six promoter regions. By use of electrophoretic mobility shift assay and DNase I footprinting assay, RifZ was proved to specially bind to all six promoter regions, which was consistent with the fact that RifZ regulated the transcription of the whole rif cluster. The binding consensus sequence was further characterized through alignment using the RifZ-protected DNA sequences. By use of bionformatic analysis, another five promoters containing the RifZ box (CTACC-N8-GGATG) were identified, among which the binding of RifZ to the promoter regions of both rifK and orf18 (AMED_0645) was further verified. As RifZ directly regulates the transcription of all operons within the rif cluster, we propose that RifZ is a pathway-specific regulator for the rif cluster.IMPORTANCE To this day, rifamycin and its derivatives are still the first-line antituberculosis drugs. The biosynthesis of rifamycin has been extensively studied, and most biosynthetic processes have been characterized. However, little is known about the regulation of the transcription of the rifamycin biosynthetic gene cluster (rif cluster), and no regulator has been characterized. Through the employment of transposon screening, we here characterized a LuxR family regulator, RifZ, as a direct transcriptional activator for the rif cluster. As RifZ directly regulates the transcription of the entire rif cluster, it is considered a pathway-specific regulator for rifamycin biosynthesis. Therefore, as the first regulator characterized for direct regulation of rif cluster transcription, RifZ may provide a new clue for further engineering of high-yield industrial strains.
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Xu Z, Wang Y, Chater KF, Ou HY, Xu HH, Deng Z, Tao M. Large-Scale Transposition Mutagenesis of Streptomyces coelicolor Identifies Hundreds of Genes Influencing Antibiotic Biosynthesis. Appl Environ Microbiol 2017; 83:AEM.02889-16. [PMID: 28062460 PMCID: PMC5335527 DOI: 10.1128/aem.02889-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/28/2016] [Indexed: 01/16/2023] Open
Abstract
Gram-positive Streptomyces bacteria produce thousands of bioactive secondary metabolites, including antibiotics. To systematically investigate genes affecting secondary metabolism, we developed a hyperactive transposase-based Tn5 transposition system and employed it to mutagenize the model species Streptomyces coelicolor, leading to the identification of 51,443 transposition insertions. These insertions were distributed randomly along the chromosome except for some preferred regions associated with relatively low GC content in the chromosomal core. The base composition of the insertion site and its flanking sequences compiled from the 51,443 insertions implied a 19-bp expanded target site surrounding the insertion site, with a slight nucleic acid base preference in some positions, suggesting a relative randomness of Tn5 transposition targeting in the high-GC Streptomyces genome. From the mutagenesis library, 724 mutants involving 365 genes had altered levels of production of the tripyrrole antibiotic undecylprodigiosin (RED), including 17 genes in the RED biosynthetic gene cluster. Genetic complementation revealed that most of the insertions (more than two-thirds) were responsible for the changed antibiotic production. Genes associated with branched-chain amino acid biosynthesis, DNA metabolism, and protein modification affected RED production, and genes involved in signaling, stress, and transcriptional regulation were overrepresented. Some insertions caused dramatic changes in RED production, identifying future targets for strain improvement.IMPORTANCE High-GC Gram-positive streptomycetes and related actinomycetes have provided more than 100 clinical drugs used as antibiotics, immunosuppressants, and antitumor drugs. Their genomes harbor biosynthetic genes for many more unknown compounds with potential as future drugs. Here we developed a useful genome-wide mutagenesis tool based on the transposon Tn5 for the study of secondary metabolism and its regulation. Using Streptomyces coelicolor as a model strain, we found that chromosomal insertion was relatively random, except at some hot spots, though there was evidence of a slightly preferred 19-bp target site. We then used prodiginine production as a model to systematically survey genes affecting antibiotic biosynthesis, providing a global view of antibiotic regulation. The analysis revealed 348 genes that modulate antibiotic production, among which more than half act to reduce production. These might be valuable targets in future investigations of regulatory mechanisms, for strain improvement, and for the activation of silent biosynthetic gene clusters.
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Affiliation(s)
- Zhong Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yemin Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Keith F Chater
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Hong-Yu Ou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - H Howard Xu
- Department of Biological Sciences, California State University, Los Angeles, California, USA
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Meifeng Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Genetic manipulation of secondary metabolite biosynthesis for improved production in Streptomyces and other actinomycetes. J Ind Microbiol Biotechnol 2015; 43:343-70. [PMID: 26364200 DOI: 10.1007/s10295-015-1682-x] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 08/28/2015] [Indexed: 12/18/2022]
Abstract
Actinomycetes continue to be important sources for the discovery of secondary metabolites for applications in human medicine, animal health, and crop protection. With the maturation of actinomycete genome mining as a robust approach to identify new and novel cryptic secondary metabolite gene clusters, it is critical to continue developing methods to activate and enhance secondary metabolite biosynthesis for discovery, development, and large-scale manufacturing. This review covers recent reports on promising new approaches and further validations or technical improvements of existing approaches to strain improvement applicable to a wide range of Streptomyces species and other actinomycetes.
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Chen J, Xia H, Dang F, Xu Q, Li W, Qin Z. Characterization of the chromosomal integration of Saccharopolyspora plasmid pCM32 and its application to improve production of spinosyn in Saccharopolyspora spinosa. Appl Microbiol Biotechnol 2015; 99:10141-9. [DOI: 10.1007/s00253-015-6871-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/19/2015] [Accepted: 07/23/2015] [Indexed: 10/23/2022]
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Dai R, Zhang B, Zhao G, Ding X. Site-specific recombination for cloning of large DNA fragments in vitro. Eng Life Sci 2015. [DOI: 10.1002/elsc.201400267] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Ruixue Dai
- State Key Laboratory of Genetic Engineering; Department of Microbiology and Microbial Engineering; School of Life Science; Fudan University; Shanghai P. R. China
| | - Bo Zhang
- State Key Laboratory of Genetic Engineering; Department of Microbiology and Microbial Engineering; School of Life Science; Fudan University; Shanghai P. R. China
| | - Guoping Zhao
- State Key Laboratory of Genetic Engineering; Department of Microbiology and Microbial Engineering; School of Life Science; Fudan University; Shanghai P. R. China
- Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology; Shanghai Institute for Biological Science, Chinese Academy of Science; Shanghai P. R. China
- Shanghai-MOST Key Laboratory of Health and Disease Genomics; Chinese National Human Genome Centre at Shanghai; Shanghai P. R. China
| | - Xiaoming Ding
- State Key Laboratory of Genetic Engineering; Department of Microbiology and Microbial Engineering; School of Life Science; Fudan University; Shanghai P. R. China
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Wang W, Tian J, Li L, Ge M, Zhu H, Zheng G, Huang H, Ruan L, Jiang W, Lu Y. Identification of two novel regulatory genes involved in pristinamycin biosynthesis and elucidation of the mechanism for AtrA-p-mediated regulation in Streptomyces pristinaespiralis. Appl Microbiol Biotechnol 2015; 99:7151-64. [PMID: 25957493 DOI: 10.1007/s00253-015-6638-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/19/2015] [Accepted: 04/22/2015] [Indexed: 11/25/2022]
Abstract
In this study, using a transposon-based strategy, two novel regulatory genes were identified as being involved in the biosynthesis of both pristinamycin I (PI) and II (PII) in Streptomyces pristinaespiralis, including a TetR-family regulatory gene atrA-p (SSDG_00466) and an orphan histidine kinase gene SSDG_02492. The mechanism by which AtrA-p exerted a positive role in pristinamycin production was elucidated. We showed that deletion of atrA-p resulted in a delayed production of both PI and PII as well as reduced PII production. Transcriptional analysis integrated with electrophoretic mobility shift assays (EMSAs) demonstrated that AtrA-p played a positive role in pristinamycin production by directly activating the transcription of two cluster-situated regulatory genes, spbR and papR5, which encode a γ-butyrolactone receptor protein and a TetR-family repressor, respectively. The precise AtrA-p-binding sites upstream of these two targets were determined, which allowed the identification of a relatively conserved binding motif comprising two 5-nt inverted repeats separated by a variable 5-nt sequence (5'-GGAAT-n5-ATTCC-3') possibly required for the regulation of AtrA-like regulators in Streptomyces. Base substitutions of the AtrA-p-binding sites on the genome caused similar decreases in spbR and papR5 transcription as those observed in ∆atrA-p. Taken together, herein, a novel mechanism for AtrA-dependent regulation of antibiotic biosynthesis was revealed in S. pristinaespiralis, which is distinct from those of its homologs, AtrA-c from Streptomyces coelicolor, AtrA-g from Streptomyces griseus, and AtrA from Streptomyces roseosporus that perform their effects in antibiotic biosynthesis directly via pathway-specific activator genes or the biosynthetic structural genes.
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Affiliation(s)
- Wenfang Wang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, People's Republic of China
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Mukherjee S, Thompson LK, Godin S, Schackwitz W, Lipzen A, Martin J, Blanchard JL. Population level analysis of evolved mutations underlying improvements in plant hemicellulose and cellulose fermentation by Clostridium phytofermentans. PLoS One 2014; 9:e86731. [PMID: 24466216 PMCID: PMC3899296 DOI: 10.1371/journal.pone.0086731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 12/16/2013] [Indexed: 12/17/2022] Open
Abstract
Background The complexity of plant cell walls creates many challenges for microbial decomposition. Clostridium phytofermentans, an anaerobic bacterium isolated from forest soil, directly breaks down and utilizes many plant cell wall carbohydrates. The objective of this research is to understand constraints on rates of plant decomposition by Clostridium phytofermentans and identify molecular mechanisms that may overcome these limitations. Results Experimental evolution via repeated serial transfers during exponential growth was used to select for C. phytofermentans genotypes that grow more rapidly on cellobiose, cellulose and xylan. To identify the underlying mutations an average of 13,600,000 paired-end reads were generated per population resulting in ∼300 fold coverage of each site in the genome. Mutations with allele frequencies of 5% or greater could be identified with statistical confidence. Many mutations are in carbohydrate-related genes including the promoter regions of glycoside hydrolases and amino acid substitutions in ABC transport proteins involved in carbohydrate uptake, signal transduction sensors that detect specific carbohydrates, proteins that affect the export of extracellular enzymes, and regulators of unknown specificity. Structural modeling of the ABC transporter complex proteins suggests that mutations in these genes may alter the recognition of carbohydrates by substrate-binding proteins and communication between the intercellular face of the transmembrane and the ATPase binding proteins. Conclusions Experimental evolution was effective in identifying molecular constraints on the rate of hemicellulose and cellulose fermentation and selected for putative gain of function mutations that do not typically appear in traditional molecular genetic screens. The results reveal new strategies for evolving and engineering microorganisms for faster growth on plant carbohydrates.
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Affiliation(s)
- Supratim Mukherjee
- Department of Microbiobiology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Lynmarie K. Thompson
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Stephen Godin
- Biology Department, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Wendy Schackwitz
- Genomic Technologies, Joint Genome Institute, Walnut Creek, California, United States of America
| | - Anna Lipzen
- Genomic Technologies, Joint Genome Institute, Walnut Creek, California, United States of America
| | - Joel Martin
- Genomic Technologies, Joint Genome Institute, Walnut Creek, California, United States of America
| | - Jeffrey L. Blanchard
- Department of Microbiobiology, University of Massachusetts, Amherst, Massachusetts, United States of America
- Biology Department, University of Massachusetts, Amherst, Massachusetts, United States of America
- * E-mail:
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Actinomycetes genome engineering approaches. Antonie van Leeuwenhoek 2012; 102:503-16. [DOI: 10.1007/s10482-012-9795-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 08/09/2012] [Indexed: 10/28/2022]
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