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  • Review Article
  • Published:

Discovery of microbial natural products by activation of silent biosynthetic gene clusters

Key Points

  • Microorganisms produce an array of specialized metabolites with a wide range of biological activities and potential applications, such as antibiotics, anticancer agents and agrochemicals.

  • Next-generation sequencing (NGS) technologies have led to an exponential increase in microbial genome data; mining of genome databases with bioinformatics tools enables biosynthetic gene clusters (BGCs) encoding specialized metabolites to be identified.

  • Genomic analysis reveals that many microorganisms have far greater potential to produce specialized metabolites than is suggested by classic bioactivity screens. Many BGCs in the genome are silent and are therefore not expressed under standard laboratory growth conditions.

  • A range of strategies have been developed to activate these silent BGCs and thereby gain access to their metabolic products.

  • Pleiotropic strategies induce organism-wide changes to trigger BGC expression; such strategies include variation in growth conditions, the introduction of competing species, the upregulation of global transcriptional regulators and epigenetic perturbation. These approaches can be high throughput, but are often empirical in nature and generally offer less control or predictability.

  • Pathway-specific strategies enable a more targeted approach, but are generally lower throughput. Methods include inducing the expression of pathway-specific activator genes, deleting genes encoding pathway-specific repressors, refactoring a BGC of interest to replace the natural promoters, or BGC expression in a heterologous host.

  • High-pressure liquid chromatography (HPLC), mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy are the key techniques used to isolate and characterize the metabolic products when a silent BGC has been successfully activated.

Abstract

Microorganisms produce a wealth of structurally diverse specialized metabolites with a remarkable range of biological activities and a wide variety of applications in medicine and agriculture, such as the treatment of infectious diseases and cancer, and the prevention of crop damage. Genomics has revealed that many microorganisms have far greater potential to produce specialized metabolites than was thought from classic bioactivity screens; however, realizing this potential has been hampered by the fact that many specialized metabolite biosynthetic gene clusters (BGCs) are not expressed in laboratory cultures. In this Review, we discuss the strategies that have been developed in bacteria and fungi to identify and induce the expression of such silent BGCs, and we briefly summarize methods for the isolation and structural characterization of their metabolic products.

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Figure 1: Drugs developed from microbial specialized metabolites since the turn of the century.
Figure 2: The genome mining approach for natural product discovery in microorganisms.
Figure 3: Pleiotropic strategies that have been used to activate silent biosynthetic gene clusters encoding specialized metabolites.
Figure 4: Pathway-specific strategies that have been used to induce the expression of silent biosynthetic gene clusters encoding specialized metabolites.

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References

  1. Demain, A. L. & Sanchez, S. Microbial drug discovery: 80 years of progress. J. Antibiot. 62, 5–16 (2009).

    Article  CAS  PubMed  Google Scholar 

  2. Cantrell, C. L., Dayan, F. E. & Duke, S. O. Natural products as sources for new pesticides. J. Nat. Prod. 75, 1231–1242 (2012).

    Article  CAS  PubMed  Google Scholar 

  3. Davies, J. & Davies, D. Origins and evolution of antibiotic resistance. Microbiol. Mol. Biol. Rev. 74, 417–433 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Oerke, E.-C. & Dehne, H.-W. Safeguarding production — losses in major crops and the role of crop protection. Crop Prot. 23, 275–285 (2004).

    Article  Google Scholar 

  5. Fowler, V. G. et al. Daptomycin versus standard therapy for bacteremia and endocarditis caused by Staphylococcus aureus. N. Engl. J. Med. 355, 653–655 (2006).

    Article  CAS  PubMed  Google Scholar 

  6. Louie, T. J. et al. Fidaxomicin versus vancomycin for Clostridium difficile infection. N. Engl. J. Med. 364, 422–431 (2011).

    Article  CAS  PubMed  Google Scholar 

  7. Kim, K. B. & Crews, C. M. From epoxomicin to carfilzomib: chemistry, biology, and medical outcomes. Nat. Prod. Rep. 30, 600–604 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Tulp, M. & Bohlin, L. Rediscovery of known natural compounds: nuisance or goldmine? Trends Pharmacol. Sci. 26, 175–177 (2005).

    Article  CAS  PubMed  Google Scholar 

  9. von Bubnoff, A. Seeking new antibiotics in nature's backyard. Cell 127, 867–869 (2006).

    Article  CAS  PubMed  Google Scholar 

  10. Bentley, S. D. et al. Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2). Nature 417, 141–147 (2002).

    Article  PubMed  Google Scholar 

  11. Omura, S. et al. Genome sequence of an industrial microorganism Streptomyces avermitilis: deducing the ability of producing secondary metabolites. Proc. Natl Acad. Sci. USA 98, 12215–12220 (2001).

    Article  CAS  PubMed  Google Scholar 

  12. Keller, N. P., Turner, G. & Bennett, J. W. Fungal secondary metabolism from biochemistry to genomics. Nat. Rev. Microbiol. 3, 937–947 (2005).

    Article  CAS  PubMed  Google Scholar 

  13. Challis, G. L. Exploitation of the Streptomyces coelicolor A3(2) genome sequence for discovery of new natural products and biosynthetic pathways. J. Ind. Microbiol. Biotechnol. 41, 219–232 (2014).

    Article  CAS  PubMed  Google Scholar 

  14. Challis, G. L. & Ravel, J. Coelichelin, a new peptide siderophore encoded by the Streptomyces coelicolor genome: structure prediction from the sequence of its non-ribosomal peptide synthetase. FEMS Microbiol. Lett. 187, 111–114 (2000).

    Article  CAS  PubMed  Google Scholar 

  15. Pawlik, K., Kotowska, M., Chater, K. F., Kuczek, K. & Takano, E. A cryptic type I polyketide synthase (cpk) gene cluster in Streptomyces coelicolor A3(2). Arch. Microbiol. 187, 87–99 (2007).

    Article  CAS  PubMed  Google Scholar 

  16. Nett, M., Ikeda, H. & Moore, B. S. Genomic basis for natural product biosynthetic diversity in the actinomycetes. Nat. Prod. Rep. 26, 1362–1384 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Donadio, S., Monciardini, P. & Sosio, M. Polyketide synthases and nonribosomal peptide synthetases: the emerging view from bacterial genomics. Nat. Prod. Rep. 24, 1073–1109 (2007).

    Article  CAS  PubMed  Google Scholar 

  18. Letzel, A. C., Pidot, S. J. & Hertweck, C. A genomic approach to the cryptic secondary metabolome of the anaerobic world. Nat. Prod. Rep. 30, 392–428 (2013).

    Article  CAS  PubMed  Google Scholar 

  19. Wilson, M. C. et al. An environmental bacterial taxon with a large and distinct metabolic repertoire. Nature 506, 58–62 (2014). This article reports a new taxon of 'talented' bacteria with genomes that contain multiple distinct BGCs and are therefore capable of producing a diverse repertoire of interesting specialized metabolites.

    Article  CAS  PubMed  Google Scholar 

  20. Zerikly, M. & Challis, G. L. Strategies for the discovery of new natural products by genome mining. ChemBioChem 10, 625–633 (2009).

    Article  CAS  PubMed  Google Scholar 

  21. Weber, T. et al. Metabolic engineering of antibiotic factories: new tools for antibiotic production in actinomycetes. Trends Biotechnol. 33, 15–26 (2015).

    Article  CAS  PubMed  Google Scholar 

  22. Metsker, M. L. Sequencing technologies — the next generation. Nat. Rev. Genet. 11, 31–46 (2010).

    Article  CAS  Google Scholar 

  23. Schorn, M. et al. Genetic basis for the biosynthesis of the pharmaceutically important class of epoxyketone proteasome inhibitors. ACS Chem. Biol. 9, 301–309 (2014).

    Article  CAS  PubMed  Google Scholar 

  24. Gomez-Escribano, J.-P., Song, L., Bibb, M. J. & Challis, G. L. Posttranslational β-methylation and macrolactamidination in the biosynthesis of the bottromycin complex of ribosomal peptide antibiotics. Chem. Sci. 3, 3522–3525 (2012).

    Article  CAS  Google Scholar 

  25. Izawa, M., Kawasaki, T. & Haykawa, Y. Cloning and heterologous expression of the thioviridamide biosynthesis gene cluster from Streptomyces olivoviridis. Appl. Environ. Microbiol. 79, 7110–7113 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Medema, M. H. et al. antiSMASH: rapid identification, annotation and analysis of secondary metabolite biosynthesis gene clusters. Nucleic Acids Res. 39, W339–W346 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Blin, K. et al. antiSMASH 2.0 — a versatile platform for genome mining of secondary metabolite producers. Nucleic Acids Res. 41, W204–W212 (2013). This paper details the overhaul and upgrade of the genome annotation tool antiSMASH, re-released with this publication as version 2.0.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Blin, K., Kazempour, D., Wohlleben, W. & Weber, T. Improved lanthipeptide detection and prediction for antiSMASH. PLoS ONE 9, e89420 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Khaldi, N. et al. SMURF: genomic mapping of fungal secondary metabolite clusters. Fungal Genet. Biol. 47, 736–741 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. van Heel, A. J., de Jong, A., Montalbán-López, M., Kok, J. & Kuipers, O. P. BAGEL3: automated identification of genes encoding bacteriocins and (non-)bactericidal posttranslationally modified peptides. Nucleic Acids Res. 41, W448–W453 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  31. Weber, T. In silico tools for the analysis of antibiotic biosynthetic pathways. Int. J. Med. Microbiol. 304, 230–235 (2014).

    Article  CAS  PubMed  Google Scholar 

  32. Fedorova, N., Moktali, V. & Medema, M. in Fungal Secondary Metabolism (eds Keller, N. P. & Turner, G.) 23–45 (Humana, 2012).

    Book  Google Scholar 

  33. Fischbach, M. A. & Walsh, C. T. Assembly-line enzymology for polyketide and nonribosomal peptide antibiotics: logic, machinery, and mechanisms. Chem. Rev. 106, 3468–3496 (2006).

    Article  CAS  PubMed  Google Scholar 

  34. Treangen, T. J. & Salzberg, S. L. Repetitive DNA and next-generation sequencing: computational challenges and solutions. Nat. Rev. Genet. 13, 36–46 (2012).

    Article  CAS  Google Scholar 

  35. Hoefler, B. C., Konganti, K. & Straight, P. D. De novo assembly of the Streptomyces sp. strain Mg1 genome using PacBio single-molecule sequencing. Genome Announc. 1, e00535-13 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  36. Marchler-Bauer, A. et al. CDD: a Conserved Domain Database for the functional annotation of proteins. Nucleic Acids Res. 39, D225–D229 (2011).

    Article  CAS  PubMed  Google Scholar 

  37. Challis, G. L., Ravel, J. & Townsend, C. A. Predictive, structure-based model of amino acid recognition by non-ribosomal peptide synthetase adenylation domains. Chem. Biol. 7, 211–224 (2000).

    Article  CAS  PubMed  Google Scholar 

  38. Stachelhaus, T., Mootz, H. D. & Marahiel, M. A. The specificity-conferring code of adenylation domains in nonribosomal peptide synthetases. Chem. Biol. 6, 493–505 (1999).

    Article  CAS  PubMed  Google Scholar 

  39. Haydock, S. F. et al. Divergent sequence motifs correlated with the substrate specificity of (methyl)malonyl-CoA:acyl carrier protein transacylase domains in modular polyketide synthases. FEBS Lett. 374, 246–248 (1995).

    Article  CAS  PubMed  Google Scholar 

  40. Keatinge-Clay, A. T. A tylosin ketoreductase reveals how chirality is determined in polyketides. Chem. Biol. 14, 898–908 (2007).

    Article  CAS  PubMed  Google Scholar 

  41. Kwan, D. H. et al. Prediction and manipulation of the stereochemistry of enoylreduction in modular polyketide synthases. Chem. Biol. 15, 1231–1240 (2008).

    Article  CAS  PubMed  Google Scholar 

  42. Nguyen, T. et al. Exploiting the mosaic structure of trans-acyltransferase polyketide synthases for natural product discovery and pathway dissection. Nat. Biotechnol. 26, 225–233 (2008).

    Article  CAS  PubMed  Google Scholar 

  43. Röttig, M. et al. NRPSpredictor2 — a web server for predicting NRPS adenylation domain specificity. Nucleic Acids Res. 39, W362–W367 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Bachmann, B. O. & Ravel, J. In silico prediction of microbial secondary metabolic pathways from DNA sequence data. Meth. Enzymol. 458, 181–217 (2009).

    Article  CAS  PubMed  Google Scholar 

  45. Anand, S. et al. SBSPKS: structure based sequence analysis of polyketide synthases. Nucleic Acids Res. 38, W487–W496 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Khayatt, B. I., Overmars L., Siezen, R. J. & Francke, C. Classification of the adenylation and acyl-transferase activity of NRPS and PKS systems using ensembles of substrate specific hidden Markov models. PLoS ONE 8, e62136 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Wang, J. et al. Platensimycin is a selective FabF inhibitor with potent antibiotic properties. Nature 441, 358–361 (2006).

    Article  CAS  PubMed  Google Scholar 

  48. Brakhage, A. A. Regulation of fungal secondary metabolism. Nat. Rev. Microbiol. 11, 21–32 (2013).

    Article  CAS  PubMed  Google Scholar 

  49. van Wezel, G. P. & McDowall, K. J. The regulation of the secondary metabolism of Streptomyces: new links and experimental advances. Nat. Prod. Rep. 28, 1311–1333 (2011).

    Article  CAS  PubMed  Google Scholar 

  50. Chiang, Y. M., Chang, S. L., Oakley, B. R. & Wang, C. C. Recent advances in awakening silent biosynthetic gene clusters and linking orphan clusters to natural products in microorganisms. Curr. Opin. Chem. Biol. 15, 137–143 (2011).

    Article  CAS  PubMed  Google Scholar 

  51. Scherlach, K. & Hertweck, C. Discovery of aspoquinolones A–D, prenylated quinoline-2-one alkaloids from Aspergillus nidulans, motivated by genome mining. Org. Biomol. Chem. 4, 3517–3520 (2006).

    Article  CAS  PubMed  Google Scholar 

  52. Scherlach, K., Schuemann, J., Dahse, H.-M. & Hertweck, C. Aspernidine A and B, prenylated isoindolinone alkaloids from the model fungus Aspergillus nidulans. J. Antibiot. 63, 375–377 (2010).

    Article  CAS  PubMed  Google Scholar 

  53. Lincke, T., Behnken, S., Ishida, K., Roth, M. & Hertweck, C. Closthioamide: an unprecedented polythioamide antibiotic from the strictly anaerobic bacterium Clostridium cellulolyticum. Angew. Chem. Int. Ed. Engl. 49, 2011–2013 (2010).

    Article  CAS  PubMed  Google Scholar 

  54. Kawai, K., Wang, G., Okamoto, S. & Ochi, K. The rare earth, scandium, causes antibiotic overproduction in Streptomyces spp. FEMS Microbiol. Lett. 274, 311–315 (2007).

    Article  CAS  PubMed  Google Scholar 

  55. Tanaka, Y., Hosaka, T. & Ochi, K. Rare earth elements activate the secondary metabolite-biosynthetic gene clusters in Streptomyces coelicolor A3(2). J. Antibiot. 63, 477–481 (2010).

    Article  CAS  PubMed  Google Scholar 

  56. Seyedsayamdost, M. R. High-throughput platform for the discovery of elicitors of silent bacterial gene clusters. Proc. Natl Acad. Sci. USA 111, 7266–7271 (2014). This study describes a new high-throughput platform for discovering elicitors that activate silent BGCs.

    Article  CAS  PubMed  Google Scholar 

  57. Craney, A., Ozimok, C., Pimentel-Elardo, S. M., Capretta, A. & Nodwell, J. R. Chemical perturbation of secondary metabolism demonstrates important links to primary metabolism. Chem. Biol. 19, 1020–1027 (2012).

    Article  CAS  PubMed  Google Scholar 

  58. Kaeberlein, T., Lewis, K. & Epstein, S. S. Isolating “uncultivable” microorganisms in pure culture in a simulated natural environment. Science 296, 1127–1129 (2002).

    Article  CAS  PubMed  Google Scholar 

  59. Nichols, D. et al. Use of ichip for high-throughput in situ cultivation of “uncultivable” microbial species. Appl. Environ. Microbiol. 76, 2445–2450 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Gavrish, E. et al. Lassomycin, a ribosomally synthesized cyclic peptide, kills Mycobacterium tuberculosis by targeting the ATP-dependent protease ClpC1P1P2. Chem. Biol. 21, 509–518 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  61. Ling, L. L. et al. A new antibiotic kills pathogens without detectable resistance. Nature 517, 455–459 (2015). This report details the discovery and characterization of teixobactin, a novel broad-spectrum antibacterial agent for which there is “no detectable resistance”.

    Article  CAS  PubMed  Google Scholar 

  62. Wright, G. Antibiotics: an irresistible newcomer. Nature 517, 442–444 (2015).

    Article  CAS  PubMed  Google Scholar 

  63. Schroeckh, V. et al. Intimate bacterial–fungal interaction triggers biosynthesis of archetypal polyketides in Aspergillus nidulans. Proc. Natl Acad. Sci. USA 106, 14558–14563 (2009).

    Article  CAS  PubMed  Google Scholar 

  64. Sato, S., Morishita, T., Hosoya, T. & Ishikawa, Y. Novel pentacyclic compounds, F-9775A and F-9775B, their manufacture with Paecilomyces carneus, and their use for treatment of osteoporosis. Japanese patent application JP11001480 (1999).

  65. Onaka, H., Mori, Y., Igarashi, Y. & Furumai, T. Mycolic acid-containing bacteria induce natural-product biosynthesis in Streptomyces species. Appl. Environ. Microbiol. 77, 400–406 (2011).

    Article  CAS  PubMed  Google Scholar 

  66. König, C. C. et al. Bacterium induces cryptic meroterpenoid pathway in the pathogenic fungus Aspergillus fumigatus. ChemBioChem 14, 938–942 (2013).

    Article  CAS  PubMed  Google Scholar 

  67. Moree, W. et al. Imaging mass spectrometry of a coral microbe interaction with fungi. J. Chem. Ecol. 39, 1045–1054 (2013).

    Article  CAS  PubMed  Google Scholar 

  68. Moree, W. J. et al. Interkingdom metabolic transformations captured by microbial imaging mass spectrometry. Proc. Natl Acad. Sci. USA 109, 13811–13816 (2012). This study uses MALDI–IMS to directly visualize and identify metabolites produced by microorganisms growing on an agar plate, revealing a complex pattern of metabolite exchange between P. aeruginosa and A. fumigatus.

    Article  CAS  PubMed  Google Scholar 

  69. Medema, M. H. et al. Pep2Path: automated mass spectrometry-guided genome mining of peptidic natural products. PLoS Comp. Biol. 10, e1003822 (2014).

    Article  CAS  Google Scholar 

  70. Mohimani, H. et al. NRPquest: coupling mass spectrometry and genome mining for nonribosomal peptide discovery. J. Nat. Prod. 77, 1902–1909 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  71. Mohimani, H. et al. Automated genome mining of ribosomal peptide natural products. ACS Chem. Biol. 9, 1545–1551 (2014). References 69–71 describe platforms that combine tandem mass spectrometry and bioinformatics to search for ribosomally biosynthesized and post-translationally modified peptides.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Ochi, K. & Hosaka, T. New strategies for drug discovery: activation of silent or weakly expressed microbial gene clusters. Appl. Microbiol. Biotechnol. 97, 87–98 (2013).

    Article  CAS  PubMed  Google Scholar 

  73. Shima, J., Hesketh, A., Okamoto, S., Kawamoto, S. & Ochi, K. Induction of actinorhodin production by rpsL (encoding ribosomal protein S12) mutations that confer streptomycin resistance in Streptomyces lividans and Streptomyces coelicolor A3(2). J. Bacteriol. 178, 7276–7284 (1996).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Bibb, M. J. Regulation of secondary metabolism in streptomycetes. Curr. Opin. Microbiol. 8, 208–215 (2005).

    Article  CAS  PubMed  Google Scholar 

  75. Artsimovitch, I. et al. Structural basis for transcription regulation by alarmone ppGpp. Cell 117, 299–310 (2004).

    Article  CAS  PubMed  Google Scholar 

  76. Srivatsan, A. & Wang, J. D. Control of bacterial transcription, translation and replication by (p)ppGpp. Curr. Opin. Microbiol. 11, 100–105 (2008).

    Article  CAS  PubMed  Google Scholar 

  77. Xu, J., Tozawa, Y., Lai, C., Hayashi, H. & Ochi, K. A rifampicin resistance mutation in the rpoB gene confers ppGpp-independent antibiotic production in Streptomyces coelicolor A3(2). Mol. Genet. Genom. 268, 179–189 (2002).

    Article  CAS  Google Scholar 

  78. Hosaka, T. et al. Antibacterial discovery in actinomycetes strains with mutations in RNA polymerase or ribosomal protein S12. Nat. Biotechnol. 27, 462–464 (2009). This article reports the discovery of the piperidamycins, a novel class of antibiotics from S. mauvecolor , using a pleiotropic activation strategy; antibiotics are applied to induce spontaneous mutations in ribosomal proteins and thus induce BGC expression.

    Article  CAS  PubMed  Google Scholar 

  79. Gomez-Escribano, J. P. et al. Structure and biosynthesis of the unusual polyketide alkaloid coelimycin P1, a metabolic product of the cpk gene cluster of Streptomyces coelicolor M145. Chem. Sci. 3, 2716–2720 (2012). This paper describes the discovery of the novel polyketide alkaloid coelimycin P1 in S. coelicolor through a strategy that combines mutation of ribosomal proteins with genetic manipulation to increase expression of the cryptic cpk cluster.

    Article  CAS  Google Scholar 

  80. Gottelt, M., Kol, S., Gomez-Escribano, J. P., Bibb, M. & Takano, E. Deletion of a regulatory gene within the cpk gene cluster reveals novel antibacterial activity in Streptomyces coelicolor A3(2). Microbiology 156, 2343–2353 (2010).

    Article  CAS  PubMed  Google Scholar 

  81. Yin, W. & Keller, N. Transcriptional regulatory elements in fungal secondary metabolism. J. Microbiol. 49, 329–339 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  82. Bayram, Ö. et al. VelB/VeA/LaeA complex coordinates light signal with fungal development and secondary metabolism. Science 320, 1504–1506 (2008).

    Article  CAS  PubMed  Google Scholar 

  83. Bok, J. W. & Keller, N. P. LaeA, a regulator of secondary metabolism in Aspergillus spp. Eukaryot. Cell 3, 527–535 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  84. Bok, J. W. et al. Genomic mining for Aspergillus natural products. Chem. Biol. 13, 31–37 (2006).

    Article  CAS  PubMed  Google Scholar 

  85. He, J. et al. Cytotoxic and other metabolites of Aspergillus inhabiting the rhizosphere of Sonoran desert plants. J. Nat. Prod. 67, 1985–1991 (2004).

    Article  CAS  PubMed  Google Scholar 

  86. Behnken, S., Lincke, T., Kloss, F., Ishida, K. & Hertweck, C. Antiterminator-mediated unveiling of cryptic polythioamides in an anaerobic bacterium. Angew. Chem. Int. Ed. Engl. 51, 2425–2428 (2012).

    Article  CAS  PubMed  Google Scholar 

  87. Herbert, K. M. et al. E. coli NusG inhibits backtracking and accelerates pause-free transcription by promoting forward translocation of RNA polymerase. J. Mol. Biol. 399, 17–30 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  88. McKenzie, N. L. et al. Induction of antimicrobial activities in heterologous streptomycetes using alleles of the Streptomyces coelicolor gene absA1. J. Antibiot. 63, 177–182 (2010).

    Article  CAS  PubMed  Google Scholar 

  89. Felsenfeld, G. & Groudine, M. Controlling the double helix. Nature 421, 448–453 (2003).

    Article  CAS  PubMed  Google Scholar 

  90. Brosch, G., Loidl, P. & Graessle, S. Histone modifications and chromatin dynamics: a focus on filamentous fungi. FEMS Microbiol. Rev. 32, 409–439 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  91. Cichewicz, R. H. Epigenome manipulation as a pathway to new natural product scaffolds and their congeners. Nat. Prod. Rep. 27, 11–22 (2010).

    Article  CAS  PubMed  Google Scholar 

  92. Shwab, E. K. et al. Histone deacetylase activity regulates chemical diversity in Aspergillus. Eukaryot. Cell 6, 1656–1664 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  93. Bok, J. W. et al. Chromatin-level regulation of biosynthetic gene clusters. Nat. Chem. Biol. 5, 462–464 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  94. Wu, Y. et al. Emodin-mediated protection from acute myocardial infarction via inhibition of inflammation and apoptosis in local ischemic myocardium. Life Sci. 81, 1332–1338 (2007).

    Article  CAS  PubMed  Google Scholar 

  95. Williams, R. B., Henrikson, J. C., Hoover, A. R., Lee, A. E. & Cichewicz, R. H. Epigenetic remodeling of the fungal secondary metabolome. Org. Biomol. Chem. 6, 1895–1897 (2008).

    Article  CAS  PubMed  Google Scholar 

  96. Henrikson, J. C., Hoover, A. R., Joyner, P. M. & Cichewicz, R. H. A chemical epigenetics approach for engineering the in situ biosynthesis of a cryptic natural product from Aspergillus niger. Org. Biomol. Chem. 7, 435–438 (2009).

    Article  CAS  PubMed  Google Scholar 

  97. Asai, T. et al. Structurally diverse chaetophenol productions induced by chemically mediated epigenetic manipulation of fungal gene expression. Org. Lett. 15, 3346–3349 (2013).

    Article  CAS  PubMed  Google Scholar 

  98. Wang, X. et al. Chemical epigenetics alters the secondary metabolite composition of guttate excreted by an Atlantic-Forest-soil-derived Penicillium citreonigrum. J. Nat. Prod. 73, 942–948 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  99. Bergmann, S. et al. Genomics-driven discovery of PKS–NRPS hybrid metabolites from Aspergillus nidulans. Nat. Chem. Biol. 3, 213–217 (2007).

    Article  CAS  PubMed  Google Scholar 

  100. Shimizu, T., Kinoshita, H. & Nihira, T. Identification and in vivo functional analysis by gene disruption of ctnA, an activator gene involved in citrinin biosynthesis in Monascus purpureus. Appl. Environ. Microbiol. 73, 5097–5103 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  101. Chiang, Y. M. et al. A gene cluster containing two fungal polyketide synthases encodes the biosynthetic pathway for a polyketide, asperfuranone, in Aspergillus nidulans. J. Am. Chem. Soc. 131, 2965–2970 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  102. Duncan, S. J. et al. Isolation and structure elucidation of chlorofusin, a novel p53–MDM2 antagonist from a Fusarium sp. J. Am. Chem. Soc. 123, 554–560 (2001).

    Article  CAS  PubMed  Google Scholar 

  103. Laureti, L. et al. Identification of a bioactive 51-membered macrolide complex by activation of a silent polyketide synthase in Streptomyces ambofaciens. Proc. Natl Acad. Sci. USA 108, 6258–6263 (2011). This article reports that constitutive overexpression of a putative pathway-specific transcriptional activator induces BGC expression, leading to the discovery of the stambomycins, which are potential leads for the development of new anticancer agents.

    Article  CAS  PubMed  Google Scholar 

  104. Corre, C., Song, L., O'Rourke, S., Chater, K. F. & Challis, G. L. 2-alkyl-4-hydroxymethylfuran-3-carboxylic acids, antibiotic production inducers discovered by Streptomyces coelicolor genome mining. Proc. Nat. Acad. Sci. USA 105, 17510–17515 (2008).

    Article  CAS  PubMed  Google Scholar 

  105. Bunet, R. et al. Characterization and manipulation of the pathway-specific late regulator AlpW reveals Streptomyces ambofaciens as a new producer of kinamycins. J. Bacteriol. 193, 1142–1153 (2011).

    Article  CAS  PubMed  Google Scholar 

  106. Sidda, J. D. et al. Discovery of a family of γ-aminobutyrate ureas via rational derepression of a silent bacterial gene cluster. Chem. Sci. 5, 86–89 (2014). This study uses the repressor deletion strategy in S. venezuelae , enabling the discovery of the gaburedins, a novel complex of γ-aminobutyrate-derived ureas.

    Article  CAS  Google Scholar 

  107. Biggins, J. B., Gleber, C. D. & Brady, S. F. Acyldepsipeptide HDAC inhibitor production induced in Burkholderia thailandensis. Org. Lett. 13, 1536–1539 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  108. Ishida, K., Lincke, T., Behnken, S. & Hertweck, C. Induced biosynthesis of cryptic polyketide metabolites in a Burkholderia thailandensis quorum sensing mutant. J. Am. Chem. Soc. 132, 13966–13968 (2010).

    Article  CAS  PubMed  Google Scholar 

  109. Guo, F. et al. Targeted activation of silent natural product biosynthesis pathways by reporter-guided mutant selection. Metab. Eng. 28, 134–142 (2015). This article introduces the concept of reporter-guided mutant selection, which combines pleiotropic mutagenesis with pathway-specific detection to visualize mutants in which transcription of the targeted BGC has been activated.

    Article  CAS  PubMed  Google Scholar 

  110. Franke, J., Ishida, K. & Hertweck, C. Genomics-driven discovery of burkholderic acid, a noncanonical, cryptic polyketide from human pathogenic Burkholderia species. Angew. Chem. Int. Ed. Engl. 51, 11611–11615 (2012).

    CAS  Google Scholar 

  111. Olano, C. et al. Activation and identification of five clusters for secondary metabolites in Streptomyces albus J1074. Microb. Biotechnol. 7, 242–256 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  112. Nakagawa, F. et al. Terferol, an inhibitor of cyclic adenosine-3,5-monophosphate phosphodiesterase. II. Structure elucidation. J. Antibiot. 37, 10–12 (1984).

    Article  CAS  PubMed  Google Scholar 

  113. Biggins, J. B., Liu, X., Feng, Z. & Brady, S. F. Metabolites from the induced expression of cryptic single operons found in the genome of Burkholderia pseudomallei. J. Am. Chem. Soc. 133, 1638–1641 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  114. Lin, X., Hopson, R. & Cane, D. E. Genome mining in Streptomyces coelicolor: molecular cloning and characterization of a new sesquiterpene synthase. J. Am. Chem. Soc. 128, 6022–6023 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  115. Chou, W. K. W. et al. Genome mining in Streptomyces avermitilis: cloning and characterization of SAV_76, the synthase for a new sesquiterpene, avermitilol. J. Am. Chem. Soc. 132, 8850–8851 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  116. McClerren, A. L. et al. Discovery and in vitro biosynthesis of haloduracin, a two-component lantibiotic. Proc. Natl Acad. Sci. USA 103, 17243–17248 (2006).

    Article  CAS  PubMed  Google Scholar 

  117. Jones, A. C. et al. Phage P1-derived artificial chromosomes facilitate heterologous expression of the FK506 gene cluster. PLoS ONE 8, e69319 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  118. Yamanaka, K. et al. Direct cloning and refactoring of a silent lipopeptide biosynthetic gene cluster yields the antibiotic taromycin A. Proc. Natl Acad. Sci. USA 111, 1957–1962 (2014).

    Article  CAS  PubMed  Google Scholar 

  119. Kim, J. H. et al. Cloning large natural product gene clusters from the environment: piecing environmental DNA gene clusters back together with TAR. Biopolymers 93, 833–844 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  120. Lazarus, C. M., Williams, K. & Bailey, A. M. Reconstructing fungal natural product biosynthetic pathways. Nat. Prod. Rep. 31, 1339–1347 (2014).

    Article  CAS  PubMed  Google Scholar 

  121. Shao, Z. & Zhao, H. in Current Protocols in Chemical Biology 65–100 (John Wiley & Sons, 2014).

    Book  Google Scholar 

  122. Shao, Z., Zhao, H. & Zhao, H. DNA assembler, an in vivo genetic method for rapid construction of biochemical pathways. Nucleic Acids Res. 37, e16 (2009).

    Article  CAS  PubMed  Google Scholar 

  123. Shao, Z., Luo, Y. & Zhao, H. Rapid characterization and engineering of natural product biosynthetic pathways via DNA assembler. Mol. Biosyst. 7, 1056–1059 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  124. Luo, Y. et al. Activation and characterization of a cryptic polycyclic tetramate macrolactam biosynthetic gene cluster. Nat. Commun. 4, 2894 (2013). This study uses a “plug-and-play” synthetic biology strategy to elicit activation of a cryptic BGC in S. griseus , which led to the discovery of three new polycyclic tetramate macrolactam natural products.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  125. Smanski, M. J. et al. Functional optimization of gene clusters by combinatorial design and assembly. Nat. Biotechnol. 32, 1241–1249 (2014). This study takes a synthetic biology approach that enables combinatorial DNA assembly and thus facilitates manipulation of large microbial gene clusters, with rapid feedback and evaluation of the resultant synthetic clusters.

    Article  CAS  PubMed  Google Scholar 

  126. Unkles, S. E., Valiante, V., Mattern, Derek, J. & Brakhage, A. A. Synthetic biology tools for bioprospecting of natural products in eukaryotes. Chem. Biol. 21, 502–508 (2014).

    Article  CAS  PubMed  Google Scholar 

  127. Klein, J. et al. Yeast synthetic biology platform generates novel chemical structures as scaffolds for drug discovery. ACS Synthet. Biol. 3, 314–323 (2014). This work reports a synthetic biology strategy for bioengineering, built on the idea that small molecules have co-evolved with their protein targets; it is applied to the production in yeast of a series of 74 novel specialized metabolites.

    Article  CAS  Google Scholar 

  128. Krug, D. & Müller, R. Secondary metabolomics: the impact of mass spectrometry-based approaches on the discovery and characterization of microbial natural products. Nat. Prod. Rep. 31, 768–783 (2014).

    Article  CAS  PubMed  Google Scholar 

  129. Bucar, F., Wube, A. & Schmid, M. Natural product isolation — how to get from biological material to pure compounds. Nat. Prod. Rep. 30, 525–545 (2013).

    Article  CAS  PubMed  Google Scholar 

  130. Breton, R. C. & Reynolds, W. F. Using NMR to identify and characterize natural products. Nat. Prod. Rep. 30, 501–524 (2013).

    Article  CAS  PubMed  Google Scholar 

  131. Owen, J. G. et al. Mapping gene clusters within arrayed metagenomic libraries to expand the structural diversity of biomedically relevant natural products. Proc. Natl Acad. Sci. USA 110, 11797–11802 (2013).

    Article  CAS  PubMed  Google Scholar 

  132. Kallifidas, D., Kang, H. S. & Brady, S. F. Tetarimycin A, an MRSA-active antibiotic identified through induced expression of environmental DNA gene clusters. J. Am. Chem. Soc. 134, 19552–19555 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  133. Chang, F. Y., Ternei, M. A., Calle, P. Y. & Brady, S. F. Discovery and synthetic refactoring of tryptophan dimer gene clusters from the environment. J. Am. Chem. Soc. 135, 17906–17912 (2013).

    Article  CAS  PubMed  Google Scholar 

  134. Jaspars, M. & Challis, G. L. Microbiology: a talented genus. Nature 506, 38–39 (2014).

    Article  CAS  PubMed  Google Scholar 

  135. Payne, D. J., Gwynn, M. N., Holmes, D. J. & Pompliano, D. L. Drugs for bad bugs: confronting the challenges of antibacterial discovery. Nat. Rev. Drug Discov. 6, 29–40 (2007).

    Article  CAS  PubMed  Google Scholar 

  136. Hajduk, P. J. & Greer, J. A decade of fragment-based drug design: strategic advances and lessons learned. Nat. Rev. Drug Discov. 6, 211–219 (2007).

    Article  CAS  PubMed  Google Scholar 

  137. Hertweck, C. The biosynthetic logic of polyketide diversity. Angew. Chem. Int. Ed. Engl. 48, 4688–4716 (2009).

    Article  CAS  PubMed  Google Scholar 

  138. Piel, J. Biosynthesis of polyketides by trans-AT polyketide synthases. Nat. Prod. Rep. 27, 996–1047 (2010).

    Article  CAS  PubMed  Google Scholar 

  139. Arnison, P. G. et al. Ribosomally synthesized and post-translationally modified peptide natural products: overview and recommendations for a universal nomenclature. Nat. Prod. Rep. 30, 108–160 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  140. Strieker, M., Tanovic, A. & Marahiel, M. A. Nonribosomal peptide synthetases: structures and dynamics. Curr. Opin. Struct. Biol. 20, 234–240 (2010).

    Article  CAS  PubMed  Google Scholar 

  141. Oves-Costales, D., Kadi, N. & Challis, G. L. The long-overlooked enzymology of a nonribosomal-peptide synthetase independent pathway for virulence-conferring siderophore biosynthesis. Chem. Commun. 2009, 6530–6541 (2009).

    Article  CAS  Google Scholar 

  142. Gao, Y., Honzatko, R. B. & Peters, R. J. Terpenoid synthase structures: a so far incomplete view of complex catalysis. Nat. Prod. Rep. 29, 1153–1175 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

P.J.R. thanks the Royal Society of Chemistry Journals Grants for International Authors for supporting a sabbatical visit to the University of Warwick, Coventry, UK. G.L.C. gratefully acknowledges the UK Biotechnology and Biological Sciences Research Council (BBSRC; grants BB/K002341/1, BB/L010852/1 and BB/L023342/1), the UK Medical Research Council (MRC; grant MR/N501839/1), the Royal Society (grant WM130033) and Syngenta for their financial support of ongoing research concerning genomics-driven natural product discovery.

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Glossary

Agrochemicals

Chemical products that are used in agriculture, such as pesticides, growth enhancers and fertilizers.

Nonribosomal peptide synthetases

(NRPSs). A family of modular multi-enzymes that catalyse the biosynthesis of many specialized peptide metabolites via a ribosome- and mRNA-independent mechanism.

Polyketide synthases

(PKSs). Multi-enzyme complexes that are responsible for the biosynthesis of polyketides via a similar mechanism to fatty acid biosynthesis. In this mechanism, polyketides (which are specialized metabolites) are assembled via the decarboxylative condensation of (alkyl)malonyl-CoA-derived extender units with an acyl-CoA-derived starter unit.

Terpene synthases

Enzymes that catalyse the formation of terpene natural products from an oligo-isoprenyl diphosphate precursor (for example, geranyl diphosphate or farnesyl diphosphate).

NRPS-independent siderophore synthetases

A family of ATP-dependent enzymes that catalyse the biosynthesis of siderophores without the involvement of nonribosomal peptide synthetases (NRPSs).

antiSMASH

(Antibiotics and secondary metabolite analysis shell). A web-based program that identifies biosynthetic gene clusters in unannotated DNA sequence assemblies.

Lanthipeptide

A type of peptide natural product that is ribosomally biosynthesised and post-translationally modified; lanthipeptides characteristically contain lanthionine (a non-proteinogenic amino acid of formula HO2CCH(NH2)CH2SCH2CH(NH2)CO2H; the monosulfide analogue of cystine) or methyl-lanthionine residues in the processed peptide. Lanthipeptides that display antibacterial activity are called lantibiotics.

Bacteriocins

Proteinaceous toxins that are produced by bacteria to inhibit competing strains.

Whole-genome shotgun sequencing

A sequencing technique in which the DNA of interest is sheared into random fragments, size selected and ligated to adaptor molecules or cloned into an appropriate vector; DNA fragments are sequenced, and the original DNA sequence is reconstructed using sequence assembly software.

Mate pair

The two sequences from opposite ends of an insert within a single clone of a genomic library. These sequences are used in conjunction with whole-genome shotgun sequencing to aid sequence assembly.

PacBio SMRT sequencing

A next-generation sequencing technology, developed by Pacific Biosciences, that uses DNA polymerase and fluorescently tagged nucleotides to follow DNA replication nucleotide by nucleotide and thus determine a DNA sequence.

In silico dereplication

The predictive, computer-based analysis of biosynthetic gene clusters to eliminate those that are likely to direct the production of known metabolites or those with closely related structures.

Alkaloids

Specialized metabolites that contain nitrogen, such as morphine, quinine, nicotine and cocaine.

Cathepsin K

A lysosomal cysteine protease involved in bone remodelling and resorption.

Polyphenols

Class of organic compounds that contain multiple phenol (hydroxybenzene) units.

Matrix-assisted laser desorption/ionization–imaging mass spectrometry

(MALDI–IMS). An analytical method that uses a laser to directly desorb and ionize molecules from a specific location within a biological sample (for example, a tissue sample or microbial colony) and detect the resulting ions by mass spectrometry.

Iturin family

A family of fungicidal cyclic lipopeptides that were first identified as products of Bacillus subtilis.

Phenazine

A tricyclic aromatic compound with the structure (C6H4)N2(C6H4); also known as dibenzo-p-diazine or dibenzopyrazine.

Siderophore

A small, high-affinity iron chelator secreted by a microorganism to sequester environmental iron.

Stringent response

A stress response in bacteria to conditions such as fatty acid limitation, amino acid starvation, iron limitation or heat shock.

Velvet complex

A group of regulatory proteins that control specialized metabolite biosynthesis in fungi and include a characteristic 150 amino acid sequence known as the velvet domain. Velvet proteins may combine with themselves (homodimers), with each other (heterodimers) or with other proteins to regulate transcription.

DNA microarrays

Collections of microscopic DNA spots (probes) adhered to a solid surface, forming the basis of fluorescence-labelling techniques to detect and quantify the expression of large numbers of genes at the same time. Also known as DNA chips or biochips.

Chromatin

The complex of DNA, histone proteins and RNA that functions to package DNA into a smaller volume and control gene expression.

Anthraquinone

A type of aromatic compound based on 9,10-dioxoanthracene. Although several isomers are possible, the term anthraquinone usually refers to the 9,10-dioxo isomer in which the keto groups are located on the central ring of the tricyclic system.

Congeners

Chemical substances that are related to each other by origin, structure or function.

Azaphilone

A type of polyketide natural product that contains a highly oxygenated bicyclic pyranoquinone core (usually referred to as isochromene) and a quaternary carbon centre.

Mycaminosylated polyketide

A polyketide with β-D-mycaminose (3,6-dideoxy-3- (dimethylamino)-D-glucopyranose) attached to one or more hydroxyl groups.

LAL family

(Large ATP-binding repressors of the LuxR family). A family of transcriptional regulators that control the expression of biosynthetic gene clusters that direct the production of specialized metabolites. LAL proteins were first identified in proteobacteria and have since been discovered in several actinobacteria.

IC50

(Half-maximal inhibitory concentration).The concentration of a compound that results in inhibition of the activity of its biological target by 50%.

TetR-like repressor proteins

Transcriptional regulators that incorporate a 47 amino acid helix–turn–helix (HTH) binding motif and a ligand-binding domain that shows sequence similarity to the tetracycline-responsive repressor of the tetracycline resistance (tetR) gene.

Quorum sensing

A mechanism by which bacteria alter their gene expression in response to the density of their local population.

E. coli–Streptomyces artificial chromosomes

(ESACs). Bacterial artificial chromosomes that can be shuttled between Escherichia coli (in which they replicate autonomously) and a Streptomyces sp. host (in which they integrate into a specific chromosomal site), thus enabling the cloning and heterologous expression of large segments (up to 140 kb) of DNA in Streptomyces spp. hosts.

Cosmid

A hybrid plasmid containing the cos (cohesive end site) sequence from phage λ; commonly used in genetic engineering as a cloning vector and to build genomic libraries.

Fosmid

A low-copy-number vector based on the Escherichia coli F factor replicon; it can hold DNA inserts of up to 40 kb, and the low copy number affords higher stability than vectors with higher copy numbers (such as cosmids).

High-pressure liquid chromatography

(HPLC). An analytical technique used to separate the components of a mixture by pumping a solution through a column of solid adsorbent material.

m/z value

The mass-to-charge ratio. This is the measured output from a mass spectrometer, which enables the identification and characterization of compounds based on their molecular mass.

NMR spectroscopy

An analytical technique that exploits the magnetic properties of certain nuclei (including those of 1H, 13C and 15N) to determine the molecular structure of compounds that contain these elements.

X-ray crystallography

An analytical technique for elucidating molecular structure, exploiting the fact that atoms in a crystalline sample cause a beam of X-rays to diffract; from the angles and intensities of the diffracted beams, a 3D image of the molecule can be derived.

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Rutledge, P., Challis, G. Discovery of microbial natural products by activation of silent biosynthetic gene clusters. Nat Rev Microbiol 13, 509–523 (2015). https://doi.org/10.1038/nrmicro3496

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