Enfumafungin synthase represents a novel lineage of fungal triterpene cyclases.

Published

Journal Article

Enfumafungin is a glycosylated fernene-type triterpenoid produced by the fungus Hormonema carpetanum. Its potent antifungal activity, mediated by its interaction with β-1,3-glucan synthase and the fungal cell wall, has led to its development into the semi-synthetic clinical candidate, ibrexafungerp (=SCY-078). We report on the preliminary identification of the enfumafungin biosynthetic gene cluster (BGC) based on genome sequencing, phylogenetic reconstruction, gene disruption, and cDNA sequencing studies. Enfumafungin synthase (efuA) consists of a terpene cyclase domain (TC) fused to a glycosyltransferase (GT) domain and thus represents a novel multifunctional enzyme. Moreover, the TC domain bears a phylogenetic relationship to bacterial squalene-hopene cyclases (SHC) and includes a typical DXDD motif within the active centre suggesting that efuA evolved from SHCs. Phylogenetic reconstruction of the GT domain indicated that this portion of the fusion gene originated from fungal sterol GTs. Eleven genes flanking efuA are putatively involved in the biosynthesis, regulation, transport and self-resistance of enfumafungin and include an acetyltransferase, three P450 monooxygenases, a dehydrogenase, a desaturase and a reductase. A hypothetical scheme for enfumafungin assembly is proposed in which the E-ring is oxidatively cleaved to yield the four-ring system of enfumafungin. EfuA represents the first member of a widespread lineage of fungal SHCs.

Full Text

Duke Authors

Cited Authors

  • Kuhnert, E; Li, Y; Lan, N; Yue, Q; Chen, L; Cox, RJ; An, Z; Yokoyama, K; Bills, GF

Published Date

  • September 2018

Published In

Volume / Issue

  • 20 / 9

Start / End Page

  • 3325 - 3342

PubMed ID

  • 30051576

Pubmed Central ID

  • 30051576

Electronic International Standard Serial Number (EISSN)

  • 1462-2920

Digital Object Identifier (DOI)

  • 10.1111/1462-2920.14333

Language

  • eng

Conference Location

  • England