Comparative Molecular Mechanisms of Biosynthesis of Naringenin and Related Chalcones in Actinobacteria and Plants: Relevance for the Obtention of Potent Bioactive Metabolites

Abstract

Naringenin and its glycosylated derivative naringin are flavonoids that are synthesized by the phenylpropanoid pathway in plants. We found that naringenin is also formed by the actinobacterium Streptomyces clavuligerus, a well-known microorganism used to industrially produce clavulanic acid. The production of naringenin in S. clavuligerus involves a chalcone synthase that uses p-coumaric as a starter unit and a P450 monoxygenase, encoded by two adjacent genes (ncs-ncyP). The p-coumaric acid starter unit is formed by a tyrosine ammonia lyase encoded by an unlinked, tal, gene. Deletion and complementation studies demonstrate that these three genes are required for biosynthesis of naringenin in S. clavuligerus. Other actinobacteria chalcone synthases use caffeic acid, ferulic acid, sinapic acid or benzoic acid as starter units in the formation of different antibiotics and antitumor agents. The biosynthesis of naringenin is restricted to a few Streptomycess species and the encoding gene cluster is present also in some Saccharotrix and Kitasatospora species. Phylogenetic comparison of S. clavuligerus naringenin chalcone synthase with homologous proteins of other actinobacteria reveal that this protein is closely related to chalcone synthases that use malonyl-CoA as a starter unit for the formation of red-brown pigment. The function of the core enzymes in the pathway, such as the chalcone synthase and the tyrosine ammonia lyase, is conserved in plants and actinobacteria. However, S. clavuligerus use a P450 monooxygenase proposed to complete the cyclization step of the naringenin chalcone, whereas this reaction in plants is performed by a chalcone isomerase. Comparison of the plant and S. clavuligerus chalcone synthases indicates that they have not been transmitted between these organisms by a recent horizontal gene transfer phenomenon. We provide a comprehensive view of the molecular genetics and biochemistry of chalcone synthases and their impact on the development of antibacterial and antitumor compounds. These advances allow new bioactive compounds to be obtained using combinatorial strategies. In addition, processes of heterologous expression and bioconversion for the production of naringenin and naringenin-derived compounds in yeasts are described.

Naringenin and Hesperidin as Promising Alternatives for Prevention and Co-Adjuvant Therapy for Breast Cancer

“…The bacterium Streptomyces clavuligerus synthesizes naringenin using p- coumaric acid and the P450 monooxygenase enzyme as pathway initiators rather than the general phenylpropanoid pathway seen in plants. Other bacteria in the genus Streptomyces can produce naringenin by the same principle, using p -coumaric acid or other pathway initiators, such as caffeic acid and benzoic acid [ 83 ].…”

Interaction of calcium responsive proteins and transcriptional factors with the PHO regulon in yeasts and fungi

“…The direct interaction of calmodulin with secondary metabolites synthesizing enzymes has been studied in the insect pathogen Beauveria bassiana; this fungus produces several secondary metabolites, including compounds derived from the phenylpropanoid pathway and non-ribosomal peptides among others. The phenylpropanoid pathway starts from phenylalanine that is converted to cinnamic acid by the phenylalanine ammonia lyase (PAL) or a related tyrosine ammonia lyase (TAL) that forms coumaric acid (Figure 2A) (Martín and Liras, 2022a). Calmodulin interacts directly with the PAL enzyme of B. bassiana and inhibits its activity (Kim et al, 2015).…”

Biosynthesis of Hesperetin, Homoeriodictyol, and Homohesperetin in a Transcriptomics-Driven Engineered Strain of Streptomyces albidoflavus

“…Different microbial hosts have been employed to produce these plant secondary metabolites, such as Saccharomyces cerevisiae [14], Escherichia coli [15], and Streptomyces albidoflavus [16]. Among the microorganisms utilized as microbial cell factories for the biosynthesis of flavonoids, Streptomyces stands out, recognized for its natural capacity to synthesize these compounds [17,18]. In order to achieve the biosynthesis of these flavonoids, the respective biosynthetic gene cluster (BGC) for each compound must be assembled using synthetic genes utilizing codon-optimized sequences for optimal expression in selected microbial hosts.…”