InterPro domain: IPR021765

Oxidase ustYa is involved in the the production of ustiloxins, toxic cyclic peptides, in fungi. Ustiloxins were found to be the first example of cyclic peptidyl secondary metabolites that are ribosomally synthesized in filamentous fungi. The homologous genes ustYa and ustYb (which are found in the gene cluster for ustiloxins) have been shown to be involved in cyclization of the peptide [ 1 , 2 , 3 ].

Other proteins in this entry include cyclochlorotine biosynthesis proteins O, P and R from Talaromyces islandicus which are encoded within a cluster of genes required for biosynthesis of the mycotoxin cyclochlorotine. CccP is probably the phenylalanine aminomutase that provides the unusual beta-Phe amino acid, but the roles of the other proteins are unknown [ 4 ].

1. Unveiling the Biosynthetic Pathway of the Ribosomally Synthesized and Post-translationally Modified Peptide Ustiloxin B in Filamentous Fungi. Angew. Chem. Int. Ed. Engl. 55, 8072-5
2. Class of cyclic ribosomal peptide synthetic genes in filamentous fungi. Fungal Genet. Biol. 86, 58-70
3. Characterization of the biosynthetic gene cluster for the ribosomally synthesized cyclic peptide ustiloxin B in Aspergillus flavus. Fungal Genet. Biol. 68, 23-30
4. The cyclochlorotine mycotoxin is produced by the nonribosomal peptide synthetase CctN in Talaromyces islandicus ('Penicillium islandicum'). Environ. Microbiol. 18, 3728-3741