A novel thermostable branching enzyme from an extremely thermophilic bacterial species, Rhodothermus obamensis
| Autor: | Masanobu Abo, Shinobu Takagi, Miyoko Hashida, Thomas Christian Beck, Ihara Michiko, Mari L. Shinohara |
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| Rok vydání: | 2002 |
| Předmět: |
DNA
Bacterial Aspergillus oryzae Molecular Sequence Data Biology medicine.disease_cause Applied Microbiology and Biotechnology 1 4-alpha-Glucan Branching Enzyme Enzyme Stability medicine Glycogen branching enzyme Escherichia coli Amino Acid Sequence Cloning Molecular Peptide sequence Phylogeny chemistry.chemical_classification Rhodothermus Bacteria Base Sequence Sequence Homology Amino Acid Thermophile General Medicine Hydrogen-Ion Concentration biology.organism_classification Recombinant Proteins Amino acid Molecular Weight Enzyme Biochemistry chemistry Genes Bacterial biology.protein Biotechnology |
| Zdroj: | Applied microbiology and biotechnology. 57(5-6) |
| ISSN: | 0175-7598 |
| Popis: | A branching enzyme (EC 2.4.1.18) gene was isolated from an extremely thermophilic bacterium, Rhodothermus obamensis. The predicted protein encodes a polypeptide of 621 amino acids with a predicted molecular mass of 72 kDa. The deduced amino acid sequence shares 42-50% similarity to known bacterial branching enzyme sequences. Similar to the Bacillus branching enzymes, the predicted protein has a shorter N-terminal amino acid extension than that of the Escherichia coli branching enzyme. The deduced amino acid sequence does not appear to contain a signal sequence, suggesting that it is an intracellular enzyme. The R. obamensis branching enzyme was successfully expressed both in E. coli and a filamentous fungus, Aspergillus oryzae. The enzyme showed optimum catalytic activity at pH 6.0-6.5 and 65 degrees C. The enzyme was stable after 30 min at 80 degrees C and retained 50% of activity at 80 degrees C after 16 h. Branching activity of the enzyme was higher toward amylose than toward amylopectin. This is the first thermostable branching enzyme isolated from an extreme thermophile. |
| Databáze: | OpenAIRE |
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