Recent Advances in Silent Gene Cluster Activation in Streptomyces

Natural products (NPs) are critical sources of drug molecules for decades. About two-thirds of natural antibiotics are produced by Streptomyces. Streptomyces have a large number of secondary metabolite biosynthetic gene clusters (SM-BGCs) that may encode NPs. However, most of these BGCs are silent under standard laboratory conditions. Hence, activation of these silent BGCs is essential to current natural products discovery research. In this review, we described the commonly used strategies for silent BGC activation in Streptomyces from two aspects. One focused on the strategies applied in heterologous host, including methods to clone and reconstruct BGCs along with advances in chassis engineering; the other focused on methods applied in native host which includes engineering of promoters, regulatory factors, and ribosomes. With the metabolic network being elucidated more comprehensively and methods optimized more high-thoroughly, the discovery of NPs will be greatly accelerated.

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Expanding the Natural Products Heterologous Expression Repertoire in the Model Cyanobacterium Anabaena sp. Strain PCC 7120: Production of Pendolmycin and Teleocidin B-4

10.26434/chemrxiv.11316098.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Patrick Videau ◽

Kaitlyn Wells ◽

Arun Singh ◽

Jessie Eiting ◽

Philip Proteau ◽

...

Keyword(s):

Natural Products ◽

Genome Mining ◽

Gene Clusters ◽

Combinatorial Biosynthesis ◽

Test Case ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Cyanobacterium Anabaena ◽

Anabaena Sp ◽

Pcc 7120

Cyanobacteria are prolific producers of natural products and genome mining has shown that many orphan biosynthetic gene clusters can be found in sequenced cyanobacterial genomes. New tools and methodologies are required to investigate these biosynthetic gene clusters and here we present the use of <i>Anabaena </i>sp. strain PCC 7120 as a host for combinatorial biosynthesis of natural products using the indolactam natural products (lyngbyatoxin A, pendolmycin, and teleocidin B-4) as a test case. We were able to successfully produce all three compounds using codon optimized genes from Actinobacteria. We also introduce a new plasmid backbone based on the native <i>Anabaena</i>7120 plasmid pCC7120ζ and show that production of teleocidin B-4 can be accomplished using a two-plasmid system, which can be introduced by co-conjugation.

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Global biogeographic sampling of bacterial secondary metabolism

eLife ◽

10.7554/elife.05048 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 74

Author(s):

Zachary Charlop-Powers ◽

Jeremy G Owen ◽

Boojala Vijay B Reddy ◽

Melinda A Ternei ◽

Denise O Guimarães ◽

...

Keyword(s):

Secondary Metabolites ◽

Genome Sequencing ◽

Geographic Distance ◽

Gene Clusters ◽

Natural World ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Road Map ◽

Two Factors ◽

Natural Products Discovery

Recent bacterial (meta)genome sequencing efforts suggest the existence of an enormous untapped reservoir of natural-product-encoding biosynthetic gene clusters in the environment. Here we use the pyro-sequencing of PCR amplicons derived from both nonribosomal peptide adenylation domains and polyketide ketosynthase domains to compare biosynthetic diversity in soil microbiomes from around the globe. We see large differences in domain populations from all except the most proximal and biome-similar samples, suggesting that most microbiomes will encode largely distinct collections of bacterial secondary metabolites. Our data indicate a correlation between two factors, geographic distance and biome-type, and the biosynthetic diversity found in soil environments. By assigning reads to known gene clusters we identify hotspots of biomedically relevant biosynthetic diversity. These observations not only provide new insights into the natural world, they also provide a road map for guiding future natural products discovery efforts.

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Comprehensive curation and analysis of fungal biosynthetic gene clusters of published natural products

Fungal Genetics and Biology ◽

10.1016/j.fgb.2016.01.012 ◽

2016 ◽

Vol 89 ◽

pp. 18-28 ◽

Cited By ~ 64

Author(s):

Yong Fuga Li ◽

Kathleen J.S. Tsai ◽

Colin J.B. Harvey ◽

James Jian Li ◽

Beatrice E. Ary ◽

...

Keyword(s):

Natural Products ◽

Gene Clusters ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters

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Phytoplankton trigger the production of cryptic metabolites in the marine actinobacteria Salinispora tropica

10.1101/2020.05.18.103358 ◽

2020 ◽

Author(s):

Audam Chhun ◽

Despoina Sousoni ◽

Maria del Mar Aguiló-Ferretjans ◽

Lijiang Song ◽

Christophe Corre ◽

...

Keyword(s):

Natural Products ◽

Secondary Metabolites ◽

Antibiotic Production ◽

Antimicrobial Effect ◽

Gene Clusters ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Marine Actinobacteria ◽

Salinispora Tropica ◽

Eukaryotic Phytoplankton

AbstractBacteria from the Actinomycete family are a remarkable source of natural products with pharmaceutical potential. The discovery of novel molecules from these organisms is, however, hindered because most of the biosynthetic gene clusters (BGCs) encoding these secondary metabolites are cryptic or silent and are referred to as orphan BGCs. While co-culture has proven to be a promising approach to unlock the biosynthetic potential of many microorganisms by activating the expression of these orphan BGCs, it still remains an underexplored technique. The marine actinobacteria Salinispora tropica, for instance, produces valuable compounds such as the anti-cancer molecule salinosporamide A but half of its putative BGCs are still orphan. Although previous studies have looked into using marine heterotrophs to induce orphan BGCs in Salinispora, the potential impact of co-culturing marine phototrophs with Salinispora has yet to be investigated. Following the observation of clear antimicrobial phenotype of the actinobacterium on a range of phytoplanktonic organisms, we here report the discovery of novel cryptic secondary metabolites produced by S. tropica in response to its co-culture with photosynthetic primary producers. An approach combining metabolomics and proteomics revealed that the photosynthate released by phytoplankton influences the biosynthetic capacities of S. tropica with both production of new molecules and the activation of orphan BGCs. Our work pioneers the use of phototrophs as a promising strategy to accelerate the discovery of novel natural products from actinobacteria.ImportanceThe alarming increase of antimicrobial resistance has generated an enormous interest in the discovery of novel active compounds. The isolation of new microbes to untap novel natural products is currently hampered because most biosynthetic gene clusters (BGC) encoded by these microorganisms are not expressed under standard laboratory conditions, i.e. mono-cultures. Here we show that co-culturing can be an easy way for triggering silent BGC. By combining state-of-the-art metabolomics and high-throughput proteomics, we characterized the activation of cryptic metabolites and silent biosynthetic gene clusters in the marine actinobacteria Salinispora tropica by the presence of phytoplankton photosynthate. We further suggest a mechanistic understanding of the antimicrobial effect this actinobacterium has on a broad range of prokaryotic and eukaryotic phytoplankton species and reveal a promising candidate for antibiotic production.

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New Approaches to Detect Biosynthetic Gene Clusters in the Environment

Medicines ◽

10.3390/medicines6010032 ◽

2019 ◽

Vol 6 (1) ◽

pp. 32 ◽

Cited By ~ 7

Author(s):

Ray Chen ◽

Hon Wong ◽

Brendan Burns

Keyword(s):

Natural Products ◽

Secondary Metabolites ◽

Gene Clusters ◽

Screening Methods ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Diverse Range ◽

Bioinformatic Tools ◽

Culture Independent ◽

Traditional Approaches

Microorganisms in the environment can produce a diverse range of secondary metabolites (SM), which are also known as natural products. Bioactive SMs have been crucial in the development of antibiotics and can also act as useful compounds in the biotechnology industry. These natural products are encoded by an extensive range of biosynthetic gene clusters (BGCs). The developments in omics technologies and bioinformatic tools are contributing to a paradigm shift from traditional culturing and screening methods to bioinformatic tools and genomics to uncover BGCs that were previously unknown or transcriptionally silent. Natural product discovery using bioinformatics and omics workflow in the environment has demonstrated an extensive distribution of BGCs in various environments, such as soil, aquatic ecosystems and host microbiome environments. Computational tools provide a feasible and culture-independent route to find new secondary metabolites where traditional approaches cannot. This review will highlight some of the advances in the approaches, primarily bioinformatic, in identifying new BGCs, especially in environments where microorganisms are rarely cultured. This has allowed us to tap into the huge potential of microbial dark matter.

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An influence of the copy number of biosynthetic gene clusters on the production level of antibiotics in a heterologous host

Journal of Biotechnology ◽

10.1016/j.jbiotec.2016.05.038 ◽

2016 ◽

Vol 232 ◽

pp. 110-117 ◽

Cited By ~ 12

Author(s):

Niko Manderscheid ◽

Bohdan Bilyk ◽

Tobias Busche ◽

Jörn Kalinowski ◽

Thomas Paululat ◽

...

Keyword(s):

Copy Number ◽

Gene Clusters ◽

Production Level ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Heterologous Host

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Understanding Thioamitide Biosynthesis Using Pathway Engineering and Untargeted Metabolomics

10.1101/2020.12.17.423248 ◽

2020 ◽

Author(s):

Tom H. Eyles ◽

Natalia M. Vior ◽

Rodney Lacret ◽

Andrew W. Truman

Keyword(s):

Biosynthetic Pathway ◽

Gene Clusters ◽

Untargeted Metabolomics ◽

Pathway Engineering ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Heterologous Host ◽

Detailed Understanding ◽

Precursor Peptide ◽

Modified Peptides

ABSTRACTThiostreptamide S4 is a thioamitide, a family of promising antitumour ribosomally synthesised and post-translationally modified peptides (RiPPs). The thioamitides are one of the most structurally complex RiPP families, yet very few thioamitide biosynthetic steps have been elucidated, even though the gene clusters of multiple thioamitides have been identified. We hypothesised that engineering the thiostreptamide S4 gene cluster in a heterologous host could provide insights into its biosynthesis when coupled with untargeted metabolomics and targeted mutations of the precursor peptide. Modified gene clusters were constructed, and in-depth metabolomics enabled a detailed understanding of the biosynthetic pathway, including the identification of an effector-like protein critical for amino acid dehydration. We use this biosynthetic understanding to bioinformatically identify new widespread families of RiPP biosynthetic gene clusters, paving the way for future RiPP discovery and engineering.

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Glutamic acid is a carrier for hydrazine during the biosyntheses of fosfazinomycin and kinamycin

10.1101/365031 ◽

2018 ◽

Author(s):

Kwo-Kwang Abraham Wang ◽

Tai L. Ng ◽

Peng Wang ◽

Zedu Huang ◽

Emily P. Balskus ◽

...

Keyword(s):

Natural Products ◽

Nitrous Acid ◽

Bond Formation ◽

Gene Clusters ◽

Biosynthetic Pathways ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Structural Differences ◽

Related Compounds ◽

Made In

AbstractFosfazinomycin and kinamycin are natural products that contain nitrogen-nitrogen (N-N) bonds but that are otherwise structurally unrelated. Despite their considerable structural differences, their biosynthetic gene clusters share a set of genes predicted to facilitate N-N bond formation. In this study, we show that for both compounds, one of the nitrogen atoms in the N-N bond originates from nitrous acid. Furthermore, we show that for both compounds, an acetylhydrazine biosynthetic synthon is generated first and then funneled via a glutamyl carrier into the respective biosynthetic pathways. Therefore, unlike other pathways to NN bond-containing natural products wherein the N-N bond is formed directly on a biosynthetic intermediate, during the biosyntheses of fosfazinomycin, kinamycin, and related compounds, the N-N bond is made in an independent pathway that forms a branch of a convergent route to structurally complex natural products.

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Recent Advances in Strategies for the Cloning of Natural Product Biosynthetic Gene Clusters

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.692797 ◽

2021 ◽

Vol 9 ◽

Author(s):

Wenfang Wang ◽

Guosong Zheng ◽

Yinhua Lu

Keyword(s):

High Efficiency ◽

Therapeutic Potential ◽

Gene Clusters ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

High Molecular Weight Dna ◽

Discovery Research ◽

Recent Advances ◽

Drug Discovery Research ◽

Dna Fragment

Microbial natural products (NPs) are a major source of pharmacological agents. Most NPs are synthesized from specific biosynthetic gene clusters (BGCs). With the rapid increase of sequenced microbial genomes, large numbers of NP BGCs have been discovered, regarded as a treasure trove of novel bioactive compounds. However, many NP BGCs are silent in native hosts under laboratory conditions. In order to explore their therapeutic potential, a main route is to activate these silent NP BGCs in heterologous hosts. To this end, the first step is to accurately and efficiently capture these BGCs. In the past decades, a large number of effective technologies for cloning NP BGCs have been established, which has greatly promoted drug discovery research. Herein, we describe recent advances in strategies for BGC cloning, with a focus on the preparation of high-molecular-weight DNA fragment, selection and optimization of vectors used for carrying large-size DNA, and methods for assembling targeted DNA fragment and appropriate vector. The future direction into novel, universal, and high-efficiency methods for cloning NP BGCs is also prospected.

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Activation and Identification of a Griseusin Cluster in Streptomyces sp. CA-256286 by Employing Transcriptional Regulators and Multi-Omics Methods

Molecules ◽

10.3390/molecules26216580 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6580

Author(s):

Charlotte Beck ◽

Tetiana Gren ◽

Francisco Javier Ortiz-López ◽

Tue Sparholt Jørgensen ◽

Daniel Carretero-Molina ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Genome Mining ◽

Gene Clusters ◽

Transcriptional Regulators ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Heterologous Host ◽

Streptomyces Sp ◽

Identification And Characterization

Streptomyces are well-known producers of a range of different secondary metabolites, including antibiotics and other bioactive compounds. Recently, it has been demonstrated that “silent” biosynthetic gene clusters (BGCs) can be activated by heterologously expressing transcriptional regulators from other BGCs. Here, we have activated a silent BGC in Streptomyces sp. CA-256286 by overexpression of a set of SARP family transcriptional regulators. The structure of the produced compound was elucidated by NMR and found to be an N-acetyl cysteine adduct of the pyranonaphtoquinone polyketide 3′-O-α-d-forosaminyl-(+)-griseusin A. Employing a combination of multi-omics and metabolic engineering techniques, we identified the responsible BGC. These methods include genome mining, proteomics and transcriptomics analyses, in combination with CRISPR induced gene inactivations and expression of the BGC in a heterologous host strain. This work demonstrates an easy-to-implement workflow of how silent BGCs can be activated, followed by the identification and characterization of the produced compound, the responsible BGC, and hints of its biosynthetic pathway.

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