title: Overexpression of a three-gene conidial pigment biosynthetic pathway in Aspergillus nidulans reveals the first NRPS known to acetylate tryptophan.
abstract: Fungal nonribosomal peptide synthetases (NRPSs) are megasynthetases that produce cyclic and acyclic peptides. In Aspergillus nidulans, the NRPS ivoA (AN10576) has been associated with the biosynthesis of grey-brown conidiophore pigments. Another gene, ivoB (AN0231), has been demonstrated to be an N-acetyl-6-hydroxytryptophan oxidase that putatively acts downstream of IvoA. A third gene, ivoC, has also been predicted to be involved in pigment biosynthesis based on publicly available genomic and transcriptomic information. In this paper, we report the replacement of the promoters of the ivoA, ivoB, and ivoC genes with the inducible promoter alcA in a single cotransformation. Co-overexpression of the three genes resulted in the production of a dark-brown pigment in hyphae. In addition, overexpression of each of the Ivo genes, ivoA-C, individually or in combination, allowed us to isolate intermediates and confirm the function of each gene. IvoA was found to be the first known NRPS to carry out the acetylation of the amino acid, tryptophan.
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: calvin.sung@medsch.ucr.edu.
authors.forename: Calvin T
authors.initials: CT
authors.lastname: Sung
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA; Drug Discovery and Development Center, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan, ROC. Electronic address: slchang1120@mail.cnu.edu.tw.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Chang
authors.affiliation: Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA. Electronic address: raentw@ku.edu.
authors.forename: Ruth
authors.initials: R
authors.lastname: Entwistle
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: green8ahn@gmail.com.
authors.forename: Green
authors.initials: G
authors.lastname: Ahn
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: tzushyang.lin@usc.edu.
authors.forename: Tzu-Shyang
authors.initials: TS
authors.lastname: Lin
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: petrovavessela@gmail.com.
authors.forename: Vessela
authors.initials: V
authors.lastname: Petrova
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA; Drug Discovery and Development Center, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan, ROC. Electronic address: ysh521@mail.cnu.edu.tw.
authors.forename: Hsu-Hua
authors.initials: HH
authors.lastname: Yeh
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: mpraseuth@gmail.com.
authors.forename: Mike B
authors.initials: MB
authors.lastname: Praseuth
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA; Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan, ROC. Electronic address: ymchiang@mail.cnu.edu.tw.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Chiang
authors.affiliation: Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA. Electronic address: boakley@ku.edu.
authors.forename: Berl R
authors.initials: BR
authors.lastname: Oakley
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA; Department of Chemistry, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: clayw@usc.edu.
authors.forename: Clay C C
authors.initials: CCC
authors.lastname: Wang
mesh_terms: D001233:Aspergillus nidulans / Q000201:enzymology / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D014442:Monophenol Monooxygenase / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics; D046908:Peptide Biosynthesis, Nucleic Acid-Independent / Q000235:genetics*; D010453:Peptide Synthases / Q000235:genetics*; D010858:Pigmentation / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development; D014364:Tryptophan / Q000096:biosynthesis
chemical_list: D005656:Fungal Proteins; D014364:Tryptophan; C067267:N-acetyl-6-hydroxytryptophan oxidase; D014442:Monophenol Monooxygenase; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase
keywords: Aspergillus nidulans; N-acetyltryptophan oxidase; Nonribosomal peptide synthetase (NRPS); Pigment biosynthesis; Tryptophan N-acetyltransferase