Isolation of Aspergillus niger creA mutants and effects of the mutations on expression of arabinases and L-arabinose catabolic enzymes
| Autor: | Marcus Matheus Catharina Gielkens, George J. G. Ruijter, P.J.I. van de Vondervoort, Sipo Vanhanen, Jantien Visser |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Arabinose
Glycoside Hydrolases Mutant Genes Fungal Repressor Gene Expression Microbiology Fungal Proteins chemistry.chemical_compound Gene Psychological repression Derepression gamma-Aminobutyric Acid Regulator gene biology Aspergillus niger Chromosome Mapping biology.organism_classification Repressor Proteins Glucose Phenotype chemistry Biochemistry Mutation |
| Zdroj: | Microbiology (Reading, England). 143 |
| ISSN: | 1350-0872 |
| Popis: | Summary: Aspergillus niger mutants relieved of carbon repression were isolated from an areA parental strain by selection of colonies that exhibited improved growth on a combination of 4-aminobutanoic acid (GABA) and D-glucose. In addition to derepression of the utilization of GABA as a nitrogen source in the presence of D-glucose, three of the four mutants also showed derepression of L-alanine and L-proline utilization. Transformation of the mutants with the A. niger creA gene, encoding the repressor protein CREA, re-established the areA phenotype on GABA/D-glucose, identifying the mutations as creA d. The creA gene mapped on chromosome IV by linkage analysis and contour-clamped homogeneous electric field hybridization. The creA mutants obtained were used to study the involvement of CREA in repression by D-glucose of arabinases and L-arabinose catabolism in A. niger. In wild-type A. niger, α-L-arabinofuranosidase A, α-L-arabinofuranosidase B, endo-arabinase, L-arabinose reductase and L-arabitol dehydrogenase were induced on L-arabinose, but addition of D-glucose prevented this induction. Repression was relieved to varying degrees in the creA mutants, showing that biosynthesis of arabinases and L-arabinose catabolic enzymes is under control of CREA. |
| Databáze: | OpenAIRE |
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