title: Characterization and engineering of the ethylmalonyl-CoA pathway towards the improved heterologous production of polyketides in Streptomyces venezuelae.
abstract: Streptomyces venezuelae has an inherent advantage as a heterologous host for polyketide production due to its fast rate of growth that cannot be endowed easily through metabolic engineering. However, the utility of S. venezuelae as a host has been limited thus far due to its inadequate intracellular reserves of the (2S)-ethylmalonyl-CoA building block needed to support the biosynthesis of polyketides preventing the efficient production of the desired metabolite, such as tylactone. Here, via precursor supply engineering, we demonstrated that S. venezuelae can be developed into a more efficient general heterologous host for the quick production of polyketides. We first identified and functionally characterized the ethylmalonyl-CoA pathway which plays a major role in supplying the (2S)-ethylmalonyl-CoA extender unit in S. venezuelae. Next, S. venezuelae was successfully engineered to increase the intracellular ethylmalonyl-CoA concentration by the deletion of the meaA gene encoding coenzyme B₁₂-dependent ethylmalonyl-CoA mutase in combination with ethylmalonate supplementation and was engineered to upregulate the expression of the heterologous tylosin PKS by overexpression of the pathway specific regulatory gene pikD. Thus, a dramatic increase (∼10-fold) in tylactone production was achieved. In addition, the detailed insights into the role of the ethylmalonyl-CoA pathway, which is present in most streptomycetes, provides a general strategy to increase the ethylmalonyl-CoA supply for polyketide biosynthesis in the most prolific family of polyketide-producing bacteria.
authors.affiliation: Department of Chemistry and Nano Science, Ewha Global Top5 Research Program, Ewha Womans University, Seoul, 120-750, South Korea.
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Jung
authors.forename: Eunji
authors.initials: E
authors.lastname: Kim
authors.forename: Young Ji
authors.initials: YJ
authors.lastname: Yoo
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Ban
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Kim
authors.forename: Yeo Joon
authors.initials: YJ
authors.lastname: Yoon
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008969:Molecular Sequence Data; D061065:Polyketides / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000214:Acyl Coenzyme A; D000900:Anti-Bacterial Agents; D061065:Polyketides; C102829:ethylmalonyl-coenzyme A