Applied and Environmental Microbiology (2004) 70, 6518-6524

Kenneth C. Ehrlich, Perng-Kuang Chang, Jiujiang Yu and Peter J. Cotty (2004)
Aflatoxin biosynthesis cluster gene cypA is required for G aflatoxin formation
Applied and Environmental Microbiology 70 (11), 6518-6524
Abstract: Aspergillus flavus isolates produce only aflatoxins B1 and B2, while Aspergillus parasiticus and Aspergillus nomius produce aflatoxins B1, B2, G1, and G2. Sequence comparison of the aflatoxin biosynthesis pathway gene cluster upstream from the polyketide synthase gene, pksA, revealed that A. flavus isolates are missing portions of genes (cypA and norB) predicted to encode, respectively, a cytochrome P450 monooxygenase and an aryl alcohol dehydrogenase. Insertional disruption of cypA in A. parasiticus yielded transformants that lack the ability to produce G aflatoxins but not B aflatoxins. The enzyme encoded by cypA has highest amino acid identity to Gibberella zeae Tri4 (38%), a P450 monooxygenase previously shown to be involved in trichodiene epoxidation. The substrate for CypA may be an intermediate formed by oxidative cleavage of the A ring of O-methylsterigmatocystin by OrdA, the P450 monooxygenase required for formation of aflatoxins B1 and B2.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Kenneth C. Ehrlich, Peter J. Cotty, Perng-Kuang Chang, Jiujiang Yu

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aspergillus flavus (plant/storage disease)
	Aspergillus parasiticus
	Aspergillus nomius