Fungal Indole Alkaloid Biosynthesis: Genetic and Biochemical Investigation of the Tryptoquialanine Pathway in Penicillium aethiopicum
- 7 February 2011
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 133 (8), 2729-2741
- https://doi.org/10.1021/ja1101085
Abstract
Tremorgenic mycotoxins are a group of indole alkaloids which include the quinazoline-containing tryptoquivaline (2) that are capable of eliciting intermittent or sustained tremors in vertebrate animals. The biosynthesis of this group of bioactive compounds, which are characterized by an acetylated quinazoline ring connected to a 6−5−5 imidazoindolone ring system via a 5-membered spirolactone, has remained uncharacterized. Here, we report the identification of a gene cluster (tqa) from P. aethiopicum that is involved in the biosynthesis of tryptoquialanine (1), which is structurally similar to 2. The pathway has been confirmed to go through an intermediate common to the fumiquinazoline pathway, fumiquinazoline F, which originates from a fungal trimodular nonribosomal peptide synthetase (NRPS). By systematically inactivating every biosynthetic gene in the cluster, followed by isolation and characterization of the intermediates, we were able to establish the biosynthetic sequence of the pathway. An unusual oxidative opening of the pyrazinone ring by an FAD-dependent berberine bridge enzyme-like oxidoreductase has been proposed based on genetic knockout studies. Notably, a 2-aminoisobutyric acid (AIB)-utilizing NRPS module has been identified and reconstituted in vitro, along with two putative enzymes of unknown functions that are involved in the synthesis of the unnatural amino acid by genetic analysis. This work provides new genetic and biochemical insights into the biosynthesis of this group of fungal alkaloids, including the tremorgens related to 2.This publication has 52 references indexed in Scilit:
- Enzymatic Processing of Fumiquinazoline F: A Tandem Oxidative-Acylation Strategy for the Generation of Multicyclic Scaffolds in Fungal Indole Alkaloid BiosynthesisBiochemistry, 2010
- Genome-Based Characterization of Two Prenylation Steps in the Assembly of the Stephacidin and Notoamide Anticancer Agents in a Marine-Derived Aspergillus sp.Journal of the American Chemical Society, 2010
- Identification of the Viridicatumtoxin and Griseofulvin Gene Clusters from Penicillium aethiopicumCell Chemical Biology, 2010
- Anthranilate-Activating Modules from Fungal Nonribosomal Peptide Assembly LinesBiochemistry, 2010
- Total biosynthesis: in vitro reconstitution of polyketide and nonribosomal peptide pathwaysNatural Product Reports, 2008
- Genomic Islands in the Pathogenic Filamentous Fungus Aspergillus fumigatusPLoS Genetics, 2008
- Cloning and sequence characterization of a non-reducing polyketide synthase gene from the lichen Xanthoparmelia semiviridisMycological Research, 2008
- The genetic basis for indole-diterpene chemical diversity in filamentous fungiMycological Research, 2008
- Isolation of New Tremorgenic Metabolites from an Ascomycete, Corynascus setosus.CHEMICAL & PHARMACEUTICAL BULLETIN, 1996
- Tremorgenic Indole Alkaloids Potently Inhibit Smooth Muscle High-Conductance Calcium-Activated Potassium ChannelsBiochemistry, 1994