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The genes coding for all the enzymes involved in the conversion of acetyl-CoA to farnesyl diphosphate (FPP) in the zeaxanthin-producing bacterium Paracoccus zeaxanthinifaciens were cloned and characterized. Two genes encoding enzymes catalysing the condensation of two acetyl-CoA molecules to acetoacetyl-CoA were found. The six enzymes involved in the conversion of acetyl-CoA and acetoacetyl-CoA to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) are grouped in an operon, designated the mevalonate operon. The gene encoding the enzyme catalysing two consecutive condensations, IPP and DMAPP to geranyl diphosphate (GPP) and IPP and GPP to FPP, is not clustered with any other gene encoding an enzyme of the isoprenoid pathway. Genes encoding enzymes involved in the biosynthesis of poly-hydroxyalkanoate and non-carotenoid isoprenoids found in P. zeaxanthinifaciens are also presented. [Copyright &y& Elsevier]

Dolichol, an isoprenoid lipid, known mainly for its function in protein glycosylation, is synthesised in the mevalonate pathway. The pathway is highly regulated, on multiple levels, by sterol and non-sterol derivatives of mevalonic acid. Farnesyl diphosphate (FPP) and/or FPP-derived molecules have been identified as the main non-sterol compounds regulating degradation of 3-hydroxy-3-methylglutaryl-CoA reductase, one of the regulatory enzymes in the mevalonate pathway. In the present review we concentrate on the effect of overexpression of farnesyl diphosphate synthase on dolichol biosynthesis in yeast. In this context the role of the Yta7 protein, belonging to the AAA ATPase family, in the regulation of FPP flux to the dolichol branch of the mevalonate pathway is discussed, and the effect of FPP and/or derived molecules on the transcription of genes encoding the first enzyme committed to dolichol biosynthesis, i.e. cis-prenyl transferase. [ABSTRACT FROM AUTHOR]

Prenyltransferase (PTase) enzymes play crucial roles in natural product biosynthesis by transferring isoprene unit(s) to target substrates, thereby generating prenylated compounds. The prenylation step leads to a diverse group of natural products with improved membrane affinity and enhanced bioactivity, as compared to the non-prenylated forms. The last two decades have witnessed increasing studies on the identification, characterization, enzyme engineering, and synthetic biology of microbial PTase family enzymes. We herein summarize several examples of microbial soluble aromatic PTases for chemoenzymatic syntheses of unnatural novel prenylated compounds., Competing Interests: We declare we have no conflict of interest., (© 2021 The Authors.)

The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action, high potency and reduced toxicity compared to today's standard drugs. However, production of brasilicardin has been hampered since the producer strain Nocardia terpenica IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism. Previously, we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Amycolatopsis japonicum. Four brasilicardin congeners, intermediates of the BraA biosynthesis, were produced. Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization. Therefore, we used a metabolic engineering approach to increase heterologous production of brasilicardin in A. japonicum . Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate (IPP) and to channel the precursor into the direction of diterpenoid biosynthesis. Both approaches contributed to an elevated heterologous production of the brasilicardin backbone, which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.