The Biosynthetic Gene Cluster of Mushroom‐Derived Antrocin Encodes Two Dual‐Functional Haloacid Dehalogenase‐like Terpene Cyclases

Abstract (−)‐Antrocin ( 1 ), produced by the medicinal mushroom Antrodia cinnamomea , is a potent antiproliferative compound. The biosynthetic gene cluster of 1 was identified, and the pathway was characterized by heterologous expression. We characterized a haloacid dehalogenase‐like terpene cyclase AncC that biosynthesizes the drimane‐type sesquiterpene (+)‐albicanol ( 2 ) from farnesyl pyrophosphate (FPP). Biochemical characterization of AncC, including kinetic studies and mutagenesis, demonstrated the functions of two domains: a terpene cyclase (TC) and a pyrophosphatase (PPase). The TC domain first cyclizes FPP to albicanyl pyrophosphate, and the PPase domain then removes the pyrophosphate to form 2 . Intriguingly, AncA (94 % sequence identity to AncC), in the same gene cluster, converts FPP into ( R )‐ trans ‐γ‐monocyclofarnesol instead of 2 . Notably, Y283/F375 in the TC domain of AncA serve as a gatekeeper in controlling the formation of a cyclofarnesoid rather than a drimane‐type scaffold.