| Autor: |
Shinohara ML; Novozymes Japan Ltd, Makuhari Techno Garden, Chiba-shi, Japan., Ihara M, Abo M, Hashida M, Takagi S, Beck TC |
| Jazyk: |
angličtina |
| Zdroj: |
Applied microbiology and biotechnology [Appl Microbiol Biotechnol] 2001 Dec; Vol. 57 (5-6), pp. 653-9. |
| DOI: |
10.1007/s00253-001-0841-3 |
| Abstrakt: |
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: |
MEDLINE |
| Externí odkaz: |
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