A fungal prenyltransferase catalyzes the regular di-prenylation at positions 20 and 21 of paxilline

Abstract

A putative indole diterpene biosynthetic gene cluster composed of eight genes was identified in a genome database of Phomopsis amygdali, and from it, biosynthetic genes of fusicoccin A were cloned and characterized. The six genes showed significant similarities to pax genes, which are essential to paxilline biosynthesis in Penicillium paxilli. Recombinants of the three putative prenyltransferase genes in the cluster were overexpressed in Escherichia coli and characterized by means of in vitro experiments. AmyG is perhaps a GGDP synthase. AmyC and AmyD were confirmed to be prenyltransferases catalyzing the transfer of GGDP to IGP and a regular di-prenylation at positions 20 and 21 of paxilline, respectively. AmyD is the first know example of an enzyme with this function. The K_m values for AmyD were calculated to be 7.6 ± 0.5 μM for paxilline and 17.9 ± 1.7 μM for DMAPP at a k_cat of 0.12 ± 0.003/s.

Graphical Abstract

An enzyme catalyzing the regular di-prenylation at positions 20 and 21 of paxilline was identified in Phomopsis amygdali and its property was characterized with recombinant

Keywords:

• indole diterpene
• paxilline
• fungi
• Phomopsis amygdali
• prenyltransferases

Acknowledgments

This study was supported by Grants-in-Aid for Scientific Research (23108101 to T. Dairi and 22108002 to H. Oikawa) from the Japan Society for the Promotion of Science (JSPS).

Notes

Abbreviations: IPP, isopentenyl diphosphate; DMAPP, dimethylallyl diphosphate; GGDP, geranylgeranyl diphosphate; FDP, farnesyl diphosphate; GDP, geranyldiphosphate; IGP, indole-3-glycerol phosphate.