Identification of Serratane Synthase Gene from the Fern Lycopodium clavatum

Abstract

Ferns are known to produce onoceroids including onoceranes and serratanes having unusual structures among triterpenes. From the fern Lycopodium clavatum, a novel onoceroid synthase gene was cloned that showed high sequence identity with a previously identified α-onocerin synthase. Functional analysis by coexpression with pre-α-onocerin synthase in yeast led to the production of tohogenol and serratenediol. The result suggested that serratanes are directly biosynthesized from pre-α-onocerin and not from α-onocerin as previously assumed.

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

“…In addition, two Arabidopsis thaliana genes encode OSCs which furnish the malabaricane skeleton 8,66–69 Lodeiro et al 65 demonstrated that the isomalabaricane core arises from a lanosterol cyclase mutant (Tyr510) while the native enzyme has yet to be discovered. Moreover, Kushiro and his team 96,97 investigated the biosynthesis of the α-onocerin skeleton and successfully identified the two genes from the fern Lycopodium clavatum , LCC and LCD of the oxidosqualene cyclase (OSC) family.…”

“…94,95 Despite the fact that these findings on α-onocerin ( 291 ) were established over six decades ago, the nature of the enzymes or genes that catalyze the two right and left cyclizations remained elusive. In 2016, Kushiro and his team 96,97 investigated the biosynthesis of α-onocerin ( 291 ) (Scheme 18) and identified the two elusive genes from the fern Lycopodium clavatum , LCC and LCD of the oxidosqualene cyclase (OSC) family. The findings demonstrated that dioxidosqualene cyclase LCC catalyzed the first cyclization to get a decalin-intermediate (ring A,B) pre-α-onocerin ( 290 ) and subsequently onocerin synthase LCD catalyzed the second cyclization to afford α-onocerin ( 291 ).…”

Construction of an artificial system for ambrein biosynthesis and investigation of some biological activities of ambrein

“…Recently, it was hypothesized that 1 is biosynthesized via the pathway 6 → 7 → 1 in sperm whales 24 . In addition, 2 enzymes are utilized to convert symmetric compounds to asymmetric fern onoceroids and carotenoids 25,26 , via a strategy similar to the one we finally adopted. It is interesting that the pathways adopted by nature are similar to the artificial pathways (Fig.…”

Analysis of the Catalytic Mechanism of Bifunctional Triterpene/Sesquarterpene Cyclase: Tyr167 Functions To Terminate Cyclization of Squalene at the Bicyclic Step

“…[11,12] Ferns utilize two enzymesf or onoceroid biosynthesis. [11,12] Ferns utilize two enzymesf or onoceroid biosynthesis.…”

“…[11,12] Ferns utilize two enzymesf or onoceroid biosynthesis. [11,12] One fern onoceroid synthase, pre-a-onocerin synthase (LCC), catalyzes the formationo fabicyclic compound. Araki et al pointedo ut that its sequence ( 254 MNIHG 258 )w as notably differentf rom that of lanosterol synthase.…”