title: The cyclochlorotine mycotoxin is produced by the nonribosomal peptide synthetase CctN in Talaromyces islandicus ('Penicillium islandicum').
abstract: Talaromyces islandicus ('Penicillium islandicum') is a widespread foodborne mold that produces numerous secondary metabolites, among them potent mycotoxins belonging to different chemical classes. A notable metabolite is the hepatotoxic and carcinogenic pentapeptide cyclochlorotine that contains the unusual amino acids β-phenylalanine, 2-aminobutyrate and 3,4-dichloroproline. Although the chemical structure has been known for over five decades, nothing is known about the biosynthetic pathway of cyclochlorotine. Bioinformatic analysis of the recently sequenced genome of T. islandicus identified a wealth of gene clusters potentially coding for the synthesis of secondary metabolites. Here, we show by RNA interference-mediated gene silencing that a nonribosomal peptide synthetase, CctN, is responsible for the synthesis of cyclochlorotine. Moreover, we identified novel cyclochlorotine chemical variants, whose production also depended on cctN expression. Surprisingly, the halogenase required for cyclochlorotine biosynthesis is not encoded in the cct cluster. Nonetheless, our findings enabled us to propose a detailed model for cyclochlorotine biosynthesis. In addition, comparative genomics revealed that cct-like clusters are present in all of the sequenced Talaromyces strains indicating a high prevalence of cyclochlorotine production ability.
authors.affiliation: Mikrobiologie und Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schafhauser
authors.affiliation: Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany.|German Centre for Infection Research (DZIF), Partner site Tübingen, 72076, Tübingen, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Kirchner
authors.affiliation: Mikrobiologie und Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kulik
authors.affiliation: Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703, HA Wageningen, The Netherlands.
authors.forename: Mieke M E
authors.initials: MM
authors.lastname: Huijbers
authors.affiliation: Allgemeine Biochemie, Technische Universität Dresden, 01069, Dresden, Germany.
authors.forename: Liane
authors.initials: L
authors.lastname: Flor
authors.affiliation: Research Laboratory in Agro-Food and Biotechnology, Charles Viollette Institute, Team ProBioGEM, Polytech-Lille, Université Lille1- Sciences et Technologies, 59655 Villeneuve d'Ascq, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Caradec
authors.affiliation: Microbiology and Biotechnology Division, Department of Food and Environmental Sciences, University of Helsinki, Viikinkaari 9, FIN-00014, Helsinki, Finland.
authors.forename: David P
authors.initials: DP
authors.lastname: Fewer
authors.affiliation: Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany.|German Centre for Infection Research (DZIF), Partner site Tübingen, 72076, Tübingen, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Gross
authors.affiliation: Research Laboratory in Agro-Food and Biotechnology, Charles Viollette Institute, Team ProBioGEM, Polytech-Lille, Université Lille1- Sciences et Technologies, 59655 Villeneuve d'Ascq, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
authors.affiliation: Institut für Botanik, Technische Universität Dresden, 01062, Dresden, Germany.
authors.forename: Linda
authors.initials: L
authors.lastname: Jahn
authors.affiliation: Microbiology and Biotechnology Division, Department of Food and Environmental Sciences, University of Helsinki, Viikinkaari 9, FIN-00014, Helsinki, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Jokela
authors.affiliation: Research Laboratory in Agro-Food and Biotechnology, Charles Viollette Institute, Team ProBioGEM, Polytech-Lille, Université Lille1- Sciences et Technologies, 59655 Villeneuve d'Ascq, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Leclère
authors.affiliation: Institut für Botanik, Technische Universität Dresden, 01062, Dresden, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Ludwig-Müller
authors.affiliation: Microbiology and Biotechnology Division, Department of Food and Environmental Sciences, University of Helsinki, Viikinkaari 9, FIN-00014, Helsinki, Finland.
authors.forename: Kaarina
authors.initials: K
authors.lastname: Sivonen
authors.affiliation: Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703, HA Wageningen, The Netherlands.
authors.forename: Willem J H
authors.initials: WJ
authors.lastname: van Berkel
authors.affiliation: Mikrobiologie und Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.|German Centre for Infection Research (DZIF), Partner site Tübingen, 72076, Tübingen, Germany.|The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kogle Alle 6, 2970, Hørsholm, Denmark.
authors.forename: Tilmann
authors.initials: T
authors.lastname: Weber
authors.affiliation: Mikrobiologie und Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.|German Centre for Infection Research (DZIF), Partner site Tübingen, 72076, Tübingen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wohlleben
authors.affiliation: Allgemeine Biochemie, Technische Universität Dresden, 01069, Dresden, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: van Pée
mesh_terms: D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D009183:Mycotoxins / Q000096:biosynthesis*; D010407:Penicillium / Q000378:metabolism; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000096:biosynthesis*; D010649:Phenylalanine / Q000378:metabolism; D032901:Talaromyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D009183:Mycotoxins; D010456:Peptides, Cyclic; C018925:chloropeptide; D010649:Phenylalanine; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase