Isolation of the patC gene encoding the cystathionine β-lyase of Lactobacillus delbrueckii subsp. bulgaricus and molecular analysis of inter-strain variability in enzyme biosynthesis a aThe GenBank accession number for the sequence determined in this work is AF423071
| Autor: | Christophe Gilbert, Dominique Aubel, Danièle Atlan, Jacques Edouard Germond |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
chemistry.chemical_classification
Methionine biology Auxotrophy Enzyme biosynthesis fungi Mutant food and beverages biology.organism_classification medicine.disease_cause Microbiology Cystathionine beta synthase enzymes and coenzymes (carbohydrates) chemistry.chemical_compound Enzyme chemistry Biochemistry hemic and lymphatic diseases biology.protein medicine Escherichia coli hormones hormone substitutes and hormone antagonists Lactobacillus delbrueckii subsp. bulgaricus |
| Zdroj: | Microbiology. 148:2029-2036 |
| ISSN: | 1465-2080 1350-0872 |
| Popis: | The patC gene encoding the cystathionine beta-lyase (CBL) of Lactobacillus delbrueckii subsp. bulgaricus NCDO 1489 was cloned and expressed in Escherichia coli. Overexpression of CBL complemented the methionine auxotrophy of an E. coli metC mutant, demonstrating in vivo that this enzyme functions as a CBL. However, PatC is distinguishable from the MetC CBLs by a low identity in amino acid sequence, a sensitivity to iodoacetic acid, greater thermostability and a lower substrate affinity. Homologues of patC were detected in the 13 Lb. delbrueckii strains studied, but only seven of them showed CBL activity. In constrast to CBL(+) strains, all CBL-deficient strains analysed were auxotrophic for methionine. This supports the hypothesis that CBLs from lactobacilli are probably involved in methionine biosynthesis. Moreover, the results of this study suggest that post-transcriptional mechanisms account for the differences in CBL activities observed between strains of Lb. delbrueckii. |
| Databáze: | OpenAIRE |
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