Expression of biosynthetic gene clusters in heterologous hosts for natural product production and combinatorial biosynthesis

Abstract

Expression of biosynthetic gene clusters in heterologous hosts for natural product production and combinatorial biosynthesis is playing an increasingly important role in natural product-based drug discovery and development programmes. This review highlights the requirements and challenges associated with this conceptually simple strategy of using surrogate hosts for the production of natural products in good yields and for the generation of novel analogues by combinatorial biosynthesis methods, taking advantage of the recombinant DNA technologies and tools available in the model hosts. Specific topics addressed include: i) the mobilisation of biosynthetic gene clusters using different vector systems; ii) the selection of suitable model heterologous hosts; iii) the requirement of post-translational protein modifications and precursor supply within the model hosts; iv) the influence of promoters and pathway regulators; and v) the choice of suitable fermentation conditions. Lastly, the use of heterologous expression in combinatorial biosynthesis is addressed. Future directions for model heterologous host engineering and the optimisation of natural product biosynthetic gene cluster expression in heterologous hosts are also discussed.

Characterization of the Saframycin A Gene Cluster fromStreptomyces lavendulaeNRRL 11002 Revealing a Nonribosomal Peptide Synthetase System for Assembling the Unusual Tetrapeptidyl Skeleton in an Iterative Manner

“…However, the natural scarcity (1 mg of ET743 per 1 kg of tunicate) and the structural complexity may ultimately limit the practical value of preparing the drug either by extraction from the natural source or by total synthesis. Recently, advances in biotechnology have provided a promising alternative to make complex natural products by genetic engineering of the biosynthetic pathways in microorganisms (5,11,13). Therefore, an alternative to economically producing ET743 or analogs is by reconstructing the biosynthetic pathway in a recombinant microorganism (8), and the success of this approach critically depends on characterization of the biosynthetic mechanism of ET743-like natural products.…”

Metabolic Engineering of Microorganisms for the Production of Natural Compounds

“…Recent advances in genetic and metabolic engineering of microorganisms are making it increasingly possible to modify and optimize host microorganisms as designed. [8] Base strains producing natural compounds can be constructed by transplanting or adopting heterologous production pathways. Then, sophisticated metabolic engineering can be performed to redirect metabolic flux toward target product formation.…”

Identification and Utility of FdmR1 as a Streptomyces Antibiotic Regulatory Protein Activator for Fredericamycin Production in Streptomyces griseus ATCC 49344 and Heterologous Hosts

“…Manipulation of the regulatory systems of specific biosynthetic pathways has been proven to be an efficient strategy in achieving heterologous expression of various compounds (15).…”

“…The successful heterologous expression of defined biosynthetic pathways calls for knowledge of large gene cluster transfer, special precursor complementation, posttranslational modifications of related proteins, and appropriate host and medium selection. Effective heterologous expression also calls for a rigorous understanding of the regulatory systems involved in secondary metabolism (15,40,45).Decades of persistent effort involving several Streptomyces model strains have unveiled the regulatory systems for some representative biosynthetic pathways, and a number of regulators responsible for initiating secondary metabolite production have been identified (6). Conclusively, the regulation of biosynthetic activation is regarded as taking place genetically at several levels.…”

“…The successful heterologous expression of defined biosynthetic pathways calls for knowledge of large gene cluster transfer, special precursor complementation, posttranslational modifications of related proteins, and appropriate host and medium selection. Effective heterologous expression also calls for a rigorous understanding of the regulatory systems involved in secondary metabolism (15,40,45).…”