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Abstract

The aflR gene is a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. There is a positive regulatory gene, aflR which required for transcriptional activation of most, if not all, of the structural genes by binding to the palindromic sequence 5'-TCGN5CGA-3' in the promoter region of the structural genes in A. parasitic, A. flavus and in A. nidulans. Adjacent to the aflR gene, a gene, aflS aflJ, is also involved in the regulation of transcription. Finally, the laeA gene, for loss of aflR expression, was shown to be involved in the global regulation of secondary metabolites, aflatoxins, sterigmatocystin (ST), penicillin and gliotoxin, in several fungal species. Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus parasiticus, Aspergillus flavus, Aspergillus nomius and a few other species. The toxic effects of aflatoxins have opposing consequences for the health of human and agricultural economics. This study will examine to understand the mechanisms of aflR gene regulation, documentation of transcriptional activation.