Reconstitution of enzymatic carbon-sulfur bond formation reveals detoxification-like strategy in fungal toxin biosynthesis.

Scharf DH, Dworschak JD, Chankhamjon P, Scherlach K, Heinekamp T, Brakhage AA, Hertweck C (2018) Reconstitution of enzymatic carbon-sulfur bond formation reveals detoxification-like strategy in fungal toxin biosynthesis. ACS Chem Biol 13(9), 2508-2512.

Abstract

Gliotoxin is a virulence factor of the human pathogen Aspergillus fumigatus, the leading cause of invasive aspergillosis. The activity of this metabolite is mediated by a transannular disulfide bond, a hallmark of the epipolythiodiketopiperazine (ETP) family. Through the creation of fungal gene deletion mutants, metabolic profiling and heterologous protein expression, we unveiled the critical role of the cytochrome P450 monooxygenase (CYP450) GliC for the stepwise bishydroxylation of the diketopiperazine (DKP) core. We show for the first time the formation of the C-S bond from the DKP in a combined assay of GliC and the glutathione-S-transferase (GST) GliG in vitro. Furthermore, we present experimental evidence for an intermediary imine species. The flexible substrate scope of GliC and GliG in combination parallels P450/GST pairs used in eukaryotic phase I/II detoxification pathways.

Leibniz-HKI-Authors

Axel A. Brakhage
Pranatchareeya Chankhamjon
Jan Dworschak
Thorsten Heinekamp
Christian Hertweck
Daniel H. Scharf
Kirstin Scherlach

Identifier

doi: 10.1021/acschembio.8b00413

PMID: 30075079