Absence of the aflatoxin biosynthesis gene, norA, allows accumulation of deoxyaflatoxin B1 in Aspergillus flavus cultures.
FEMS Microbiol Lett
; 305(1): 65-70, 2010 Apr.
Article
em En
| MEDLINE
| ID: mdl-20158523
ABSTRACT
Biosynthesis of the highly toxic and carcinogenic aflatoxins in select Aspergillus species from the common intermediate O-methylsterigmatocystin has been postulated to require only the cytochrome P450 monooxygenase, OrdA (AflQ). We now provide evidence that the aryl alcohol dehydrogenase NorA (AflE) encoded by the aflatoxin biosynthetic gene cluster in Aspergillus flavus affects the accumulation of aflatoxins in the final steps of aflatoxin biosynthesis. Mutants with inactive norA produced reduced quantities of aflatoxin B(1) (AFB(1)), but elevated quantities of a new metabolite, deoxyAFB(1). To explain this result, we suggest that, in the absence of NorA, the AFB(1) reduction product, aflatoxicol, is produced and is readily dehydrated to deoxyAFB(1) in the acidic medium, enabling us to observe this otherwise minor toxin produced in wild-type A. flavus.
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Base de dados:
MEDLINE
Assunto principal:
Aspergillus flavus
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Álcool Desidrogenase
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Proteínas Fúngicas
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Aflatoxinas
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Vias Biossintéticas
Idioma:
En
Revista:
FEMS Microbiol Lett
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos