Analyzing and Engineering the Product Selectivity of a 2-Methylenebornane Synthase.

Terpenes constitute the largest class of natural products with more than 70 000 compounds. Many different terpenes find applications in the flavor and fragrance industry or can be used as fine chemicals or drugs. In some bacteria, noncanonical terpenes with 11 carbon atoms are synthesized via a GPP-C2-methyltransferase and the subsequent conversion of 2-methyl-GPP by certain terpene synthases into mainly 2-methylisoborneol and 2-methylenebornane.

Expanding the Isoprenoid Building Block Repertoire with an IPP Methyltransferase from Streptomyces monomycini.

Many synthetic biology approaches aim at expanding the product diversity of enzymes or whole biosynthetic pathways. However, the chemical structure space of natural product forming routes is often restricted by the limited cellular availability of different starting intermediates. Although the terpene biosynthesis pathways are highly modular, their starting intermediates are almost exclusively the C units IPP and DMAPP.

Heterologous expression of 2-methylisoborneol / 2 methylenebornane biosynthesis genes in Escherichia coli yields novel C11-terpenes.

The structural diversity of terpenoids is limited by the isoprene rule which states that all primary terpene synthase products derive from methyl-branched building blocks with five carbon atoms. With this study we discover a broad spectrum of novel terpenoids with eleven carbon atoms as byproducts of bacterial 2-methylisoborneol or 2-methylenebornane synthases. Both enzymes use 2-methyl-GPP as substrate, which is synthesized from GPP by the action of a methyltransferase.