The abfB gene encoding the major α-L-arabinofuranosidase of Aspergillus nidulans: nucleotide sequence, regulation and construction of a disrupted strain
| Autor: | Jantien Visser, Daniel Ramón, Marcus Matheus Catharina Gielkens, L.H. de Graaff, Luis González-Candelas, P.J.I. van de Vondervoort, Paloma Sánchez-Torres |
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| Rok vydání: | 1999 |
| Předmět: |
Regulation of gene expression
Glycoside Hydrolases Sequence Homology Amino Acid biology Molecular Sequence Data Mutant Aspergillus niger Catabolite repression Nucleic acid sequence Sequence Analysis DNA biology.organism_classification Microbiology Molecular biology Aspergillus nidulans Gene Expression Regulation Enzymologic Biochemistry Mutagenesis Gene Expression Regulation Fungal Amino Acid Sequence Cloning Molecular Gene Trichoderma reesei |
| Zdroj: | Microbiology. 145:735-741 |
| ISSN: | 1465-2080 1350-0872 |
| DOI: | 10.1099/13500872-145-3-735 |
| Popis: | Using a DNA fragment containing the Aspergillus niger abfB gene as a probe, the homologous Aspergillus nidulans gene, designated abfB, has been cloned from a genomic library containing size-selected HindIII fragments. The nucleotide sequence of the A. nidulans abfB gene shows strong homology with the A. niger abfB, Trichoderma reesei abf-1 and Trichoderma koningii alpha-L-arabinofuranosidase/beta-xylosidase genes. Regulation of abfB expression has been investigated in cultures induced with L-arabitol. The accumulation of abfB mRNA, total alpha-L-arabinofuranosidase activity and AbfB protein levels have been determined in a wild-type A. nidulans strain as well as in different mutant strains. These strains are affected either in their response to ambient pH (paIA1 and pacC(c)14 mutants), carbon catabolite repression (creA(d)4 mutant), the ability to utilize L-arabitol as a carbon source (araA1 mutant) or a combination of both latter genotypes (araA1 creA(d)4). The results obtained indicate that the expression of the A. nidulans abfB gene was higher at acidic pHs and was superinduced in this double mutant. Furthermore, disruption of the abfB gene demonstrated that in A. nidulans AbfB is the major p-nitrophenyl alpha-L-arabinofuranoside-hydrolysing activity but at least one minor activity is expressed, which is involved in the release of L-arabinose from polysaccharides. |
| Databáze: | OpenAIRE |
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