Discovery and Characterization of a New Family of Diterpene Cyclases in Bacteria and Fungi

Abstract

Diterpene cyclases from bacteria and basidiomycete fungi are seldom studied. Here, we presented the identification and verification of EriG, a member of the UbiA superfamily, as the enzyme responsible for the cyclization of the cyathane skeleton in the mushroom Hericium erinaceum. Genome mining using the EriG protein sequence as a probe led to the discovery of a new family of ubiquitous UbiA-related diterpene cyclases in bacteria and fungi. We successfully characterized seven new diterpene cyclases from bacteria or basidiomycete fungi with the help of an engineered Escherichia coli strain and determined the structures of their corresponding products. A new diterpene with an unusual skeleton was generated during this process. The discovery of this new family of diterpene cyclases provides new insight into the UbiA superfamily.

Protonation‐Initiated Cyclization by a Class II Terpene Cyclase Assisted by Tunneling

“…Because terpenes constitute a large pool of sustainable biobricks, the generation of chiral and renewable terpene‐based fine chemicals by biocatalytic and metabolic engineering efforts currently receive significant attention. Recently, focus has been on diterpene cyclases for synthetic applications and enhanced understanding of fundamental metabolism . The class II ent ‐copalyl diphosphate synthase from S. platensis (PtmT2) investigated herein harbors a β,γ‐fold reminiscent of triterpene cyclases (Figure A) that act on nonphosphorylated C 30 substrates.…”

Chimeric Terpene Synthases Possessing both Terpene Cyclization and Prenyltransfer Activities

“…However,c onsidering that the fusion of the two catalytic domains could accelerate product flux, [16,17] further investigations into such kinds of enzymes will provide valuable insights into nature's strategy to efficiently yield terpenoids, one of the largest families of natural products. In both enzymes, the TPS domain is in the N-terminal region, whereas the PT domain is in the C-terminal region, and they are connected by an internal linker with minimal predicteds econdary structure.…”

“…The reason why such as imilar manner is adopted by both chimerice nzymes is still debatable. However,c onsidering that the fusion of the two catalytic domains could accelerate product flux, [16,17] further investigations into such kinds of enzymes will provide valuable insights into nature's strategy to efficiently yield terpenoids, one of the largest families of natural products. Moreover,b ecause only al imited number of TPS + PT chimeric enzymesh ave been functionally characterized, there is the possibility thatf urther studies on these enzymes will lead to discoveries of unprecedented molecular structures and enable explorations of the unknown chemical space of small molecules.…”

“…ChemBioChem 2018ChemBioChem , 19,1 106 -1114 www.chembiochem.org 2018 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim prenyl chain to yield prenylateda romatic compounds. [17] Nevertheless, some members of the UbiA superfamily proteins are able to catalyze the type It erpene cyclization reaction.…”

“…Nevertheless, some members of the UbiA superfamily proteins are able to catalyze the type It erpene cyclization reaction. [17]…”