Discovery and characterization of a novel sub-group of UbiA-type terpene cyclases with a distinct motif I

Abstract

A novel sub-group of UbiA-type terpene cyclases was identified from fungi, which contain a distinct motif I NQXXXXXXXED instead of the known NXXX(G/A)XXXD found in all reported UbiA-type terpene cyclases. Subsequent genome mining revealed the prevalence of this novel sub-group of UbiA-type terpene cyclases in fungi. Functional analysis of the representative cyclases indicated that they are able to generate diverse sesquiterpenes via a bisabolyl cation intermediate. Moreover, unlike canonical classes I and II terpene cyclases, these enzymes can generate the same products even if they are phylogenetically separated, and produce distinct products even if they are phylogenetically close, suggesting that it is difficult to predict their functions based on sequence similarity.