Generation of aflR disruption mutants of Aspergillus parasiticus

Citation
Jw. Cary et al., Generation of aflR disruption mutants of Aspergillus parasiticus, APPL MICR B, 53(6), 2000, pp. 680-684
Citations number
25
Categorie Soggetti
Biotecnology & Applied Microbiology",Microbiology
Journal title
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
ISSN journal
01757598 → ACNP
Volume
53
Issue
6
Year of publication
2000
Pages
680 - 684
Database
ISI
SICI code
0175-7598(200006)53:6<680:GOADMO>2.0.ZU;2-7
Abstract
The aflR gene of Aspergillus parasiticus and A. flavus encodes a binuclear zinc-finger, DNA-binding protein, AflR, responsible for activating the tran scription of all known aflatoxin biosynthetic genes including itself. Studi es to determine how environmental and nutritional factors affect aflR expre ssion and hence aflatoxin production in A. parasiticus have been difficult to perform due to the lack of aflR "knockout" mutants. Transformation of an O-methylsterigmatocystin (OMST)-accumulating strain of A. parasiticus with an aflR-niaD gene disruption vector resulted in clones harboring a recombi nationally inactivated aflR gene which no longer produced OMST or aflR tran script. By transformation of this aflR disruptant strain with constructs co ntaining mutated versions of the aflR promoter, we identified three cis-act ing sites that were necessary for aflR function: an AflR-binding site, a Pa cC-binding site, and a G + A-rich site near the transcription start site of aflR.