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In order to investigate the mechanism of carbon catabolite repression in the industrially important fungus Trichoderma reesei, degenerated PCR-primers were designed to amplify a 0.7-bp fragment of the cre1 gene, which was used to clone the entire gene. It encodes a 402-amino acid protein with a calculated M(r) of 43.6 kDa. Its aa-sequence shows 55.6% and(More)
The niaD and niiA genes of Aspergillus nidulans, which code, respectively, for nitrate and nitrite reductases, are divergently transcribed, and their ATGs are separated by 1,200 bp. The genes are under the control of the positively acting NirA transcription factor, which mediates nitrate induction. The DNA binding domain of NirA was expressed as a fusion(More)
The filamentous fungus Trichoderma reesei forms two specific, xylan-inducible xylanases encoded by xyn1 and xyn2 to degrade the beta-1,4-D-xylan backbone of hemicelluloses. This enzyme system is formed in the presence of xylan, but not glucose. The molecular basis of the absence of xylanase I formation on glucose was the purpose of this study. Northern(More)
The linked niiA and niaD genes of Aspergillus nidulans are transcribed divergently. The expression of these genes is subject to a dual control system. They are induced by nitrate and repressed by ammonium. AreA mediates derepression in the absence of ammonium and NirA supposedly mediates nitrate induction. Out of 10 GATA sites, a central cluster (sites 5-8)(More)
The creA gene of A. nidulans encodes a wide-domain regulatory protein mediating carbon catabolite repression. Northern blot analysis of creA mRNA revealed a complex expression profile: the addition of monosaccharides to a carbon-starved culture of A. nidulans provoked a strong transient stimulation of creA transcript formation within a few minutes. In the(More)
The nucleotide sequence of nirA, mediating nitrate induction in Aspergillus nidulans, has been determined. Alignment of the cDNA and the genomic DNA sequence indicates that the gene contains four introns and encodes a protein of 892 amino acids. The deduced NIRA protein displays all characteristics of a transcriptional activator. A putative double-stranded(More)
Fungal secondary metabolites are important bioactive compounds but the conditions leading to expression of most of the putative secondary metabolism (SM) genes predicted by fungal genomics are unknown. Here we describe a novel mechanism involved in SM-gene regulation based on the finding that, in Aspergillus nidulans, mutants lacking components involved in(More)
We have investigated the effect of disruption of the bgl1-(beta-glucosidase l-encoding) gene of Trichoderma reesei on the formation of other beta-glucosidase activities and on the induction of cellulases. To this end the bgl1 locus was disrupted by insertion of the Aspergillus nidulans amdS (acetamidase-encoding) gene. The bgl1-disrupted strain did not(More)
Oxidation of ammonia by nitrifying microorganisms is a major pathway that fertilizer nitrogen (N) may take upon application to agricultural soils, but the relative roles of bacterial (AOB) vs. archaeal (AOA) ammonia oxidizers are controversial. We explored the effects of various forms of mineral N fertilizer on the AOB and AOA community dynamics in two(More)
Loss-of-function Aspergillus nidulans CclA, a Bre2 ortholog involved in histone H3 lysine 4 methylation, activated the expression of cryptic secondary metabolite clusters in A. nidulans. One new cluster generated monodictyphenone, emodin and emodin derivatives, whereas a second encoded two anti-osteoporosis polyketides, F9775A and F9775B. Modification of(More)