Heterologous Production of 6-Deoxyerythronolide B in Escherichia coli through the Wood Werkman Cycle.

R Axayacatl Gonzalez-Garcia,Lars K Nielsen,Esteban Marcellin

doi:10.3390/metabo10060228

R Axayacatl Gonzalez-Garcia, Lars K Nielsen + Show 1 more

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https://doi.org/10.3390/metabo10060228

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Abstract

Polyketides are a remarkable class of natural products with diverse functional and structural diversity. The class includes many medicinally important molecules with antiviral, antimicrobial, antifungal and anticancer properties. Native bacterial, fungal and plant hosts are often difficult to cultivate and coax into producing the desired product. As a result, Escherichia coli has been used for the heterologous production of polyketides, with the production of 6-deoxyerythronolide B (6-dEB) being the first example. Current strategies for production in E. coli require feeding of exogenous propionate as a source for the precursors propionyl-CoA and S-methylmalonyl-CoA. Here, we show that heterologous polyketide production is possible from glucose as the sole carbon source. The heterologous expression of eight genes from the Wood-Werkman cycle found in Propionibacteria, in combination with expression of the 6-dEB synthases DEBS1, DEBS2 and DEBS3 resulted in 6-dEB formation from glucose as the sole carbon source. Our results show that the Wood-Werkman cycle provides the required propionyl-CoA and the extender unit S-methylmalonyl-CoA to produce up to 0.81 mg/L of 6-dEB in a chemically defined media.

Highlights

Natural products are our richest source of molecules with antimicrobial, antifungal, pesticide and anticancer activities [1]
Our results show that the anaerobic pathway can sustain the production of propionate that the anaerobic pathway can sustain the production of propionate and 6-deoxyerythronolide B (6-dEB) from glucose
We evaluated the feasibility of using a synthetic Wood-Werkman cycle as a source of propionyl-coenzyme A (CoA) and S-methylmalonyl-CoA, the intermediaries required for the synthesis of 6-dEB

Summary

Introduction

Natural products are our richest source of molecules with antimicrobial, antifungal, pesticide and anticancer activities [1] They are usually associated with the secondary metabolism of organisms, these molecules are generally derived from coenzyme A (CoA), shikimate, mevalonate and. Among the different classes of natural products, polyketides represent a large family of linear or cyclic poly-β-ketones produced by several microorganisms and plants [3]. They are synthesized by enzymatic complexes, known as polyketide synthases (PKS), through successive rounds of decarboxylative condensations between an acyl-CoA thioester and a β-carboxy thioester, in a manner that resembles fatty acid biosynthesis. Type I or multimodular PKS (mPKS) work to an assembly line, where each domain is responsible for the extension of the polyketide by the condensation and selective reduction of an acyl-CoA building block [5]

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