Dataset Information

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.

SUBMITTER: Sung CT

PROVIDER: S-EPMC6430764 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Overexpression of a three-gene conidial pigment biosynthetic pathway in Aspergillus nidulans reveals the first NRPS known to acetylate tryptophan.

Sung Calvin T CT Chang Shu-Lin SL Entwistle Ruth R Ahn Green G Lin Tzu-Shyang TS Petrova Vessela V Yeh Hsu-Hua HH Praseuth Mike B MB Chiang Yi-Ming YM Oakley Berl R BR Wang Clay C C CCC

Fungal genetics and biology : FG & B 20170117

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 t ...[more]

PMID: 28108400

Similar Datasets

Project description:Aspergillus fumigatus, a filamentous fungus producing bluish-green conidia, is an important opportunistic pathogen that primarily affects immunocompromised patients. Conidial pigmentation of A. fumigatus significantly influences its virulence in a murine model. In the present study, six genes, forming a gene cluster spanning 19 kb, were identified as involved in conidial pigment biosynthesis in A. fumigatus. Northern blot analyses showed the six genes to be developmentally regulated and expressed during conidiation. The gene products of alb1 (for "albino 1"), arp1 (for "aspergillus reddish-pink 1"), and arp2 have high similarity to polyketide synthases, scytalone dehydratases, and hydroxynaphthalene reductases, respectively, found in the dihydroxynaphthalene (DHN)-melanin pathway of brown and black fungi. The abr1 gene (for "aspergillus brown 1") encodes a putative protein possessing two signatures of multicopper oxidases. The abr2 gene product has homology to the laccase encoded by the yA gene of Aspergillus nidulans. The function of ayg1 (for "aspergillus yellowish-green 1") remains unknown. Involvement of the six genes in conidial pigmentation was confirmed by the altered conidial color phenotypes that resulted from disruption of each gene in A. fumigatus. The presence of a DHN-melanin pathway in A. fumigatus was supported by the accumulation of scytalone and flaviolin in the arp1 deletant, whereas only flaviolin was accumulated in the arp2 deletants. Scytalone and flaviolin are well-known signature metabolites of the DHN-melanin pathway. Based on DNA sequence similarity, gene disruption results, and biochemical analyses, we conclude that the 19-kb DNA fragment contains a six-gene cluster which is required for conidial pigment biosynthesis in A. fumigatus. However, the presence of abr1, abr2, and ayg1 in addition to alb1, arp1, and arp2 suggests that conidial pigment biosynthesis in A. fumigatus is more complex than the known DHN-melanin pathway.

Dataset Information

Overexpression of a three-gene conidial pigment biosynthetic pathway in Aspergillus nidulans reveals the first NRPS known to acetylate tryptophan.

Publications

Overexpression of a three-gene conidial pigment biosynthetic pathway in Aspergillus nidulans reveals the first NRPS known to acetylate tryptophan.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets