ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Repressor-AFLR interaction modulates aflatoxin biosynthesis in Aspergillus parasiticus (1999)
    Springer
    Mycopathologia 147 (1999), S. 105-112 
    Details
    ISSN: 1573-0832
    Keywords: Aflatoxin ; aflR ; Aspergillus parasiticus ; repressor ; sclerotia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Regulation of aflatoxin (AF) biosynthesis likely involves a complex interplay of positive- and negative-acting factors that are affected by physiological cues responsive to internal and external stimuli. These factors, presumably, modulate the expression of the AF pathway-specific regulatory gene, aflR, whose product, AFLR, a zinc cluster transcription factor, then turns on or off the transcription of other AF genes. To determine if the AFLR carboxyl region (AFLRC) interacts with positive-or negative-acting proteins, we fused the Aspergillus parasiticus aflR carboxyl coding region(aflRC) to the promoter of A. parasiticusnitrite reductase gene (niiA(p)::aflRC), and transformed it into A. parasiticus SRRC 2043. Transformants that contained two copies of niiA(p)::aflRC, one at the niaD locus and another at the aflR locus, over produced AF precursors independent of the nitrogen source. The higher copy number of the integrated niiA(p)::aflRC correlated with increased production of AF precursors by the transformants as well as increased expression of both aflRC and native aflR in potato dextrose broth and A & M medium. Since aflRC does not encode a DNA-binding domain, the expressed AFLRC should not bind to the promoters of AF pathway genes and affect transcription directly. The results are consistent with AFLRC titrating out a putative repressor that interacts with AFLR under different growth conditions and modulates AF biosynthesis. This interaction also indirectly affects sclerotial development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007157309168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    TheAspergillus parasiticus polyketide synthase genepksA, a homolog ofAspergillus nidulans wA, is required for aflatoxin B1 biosynthesis (1995)
    Springer
    Molecular genetics and genomics 248 (1995), S. 270-277 
    Details
    ISSN: 1617-4623
    Keywords: Polyketide synthase gene ; Aflatoxin ; Aspergillus parasiticus ; Gene cluster Anthraquinone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aflatoxins comprise a group of polyketide-derived carcinogenic mycotoxins produced byAspergillus parasiticus andAspergillus flavus. By transformation with a disruption construct, pXX, we disrupted the aflatoxin pathway inA. parasiticus SRRC 2043, resulting in the inability of this strain to produce aflatoxin intermediates as well as a major yellow pigment in the transformants. The disruption was attributed to a single-crossover, homologous integration event between pXX and the recipientA. parasiticus genome at a specific locus, designatedpksA. Sequence analysis suggest thatpksA is a homolog of theAspergillus nidulans wA gene, a polyketide synthase gene involved in conidial wall pigment biosynthesis. The conservedβ-ketoacyl synthase, acyltransferase and acyl carrier-protein domains were present in the deduced amino acid sequence of thepksA product. Noβ-ketoacyl reductase and enoyl reductase domains were found, suggesting thatpksA does not encode catalytic activities for processingβ-carbon similar to those required for long chain fatty acid synthesis. ThepksA gene is located in the aflatoxin pathway gene cluster and is linked to thenor-1 gene, an aflatoxin pathway gene required for converting norsolorinic acid to averantin. These two genes are divergently transcribed from a 1.5 kb intergenic region. We propose thatpksA is a polyketide synthase gene required for the early steps of aflatoxin biosynthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02191593
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...