Extremophiles : life under extreme conditions, 2007-01, Vol.11 (1), p.75-83
2007
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- Autor(en) / Beteiligte
- Titel
- Cloning and characterization of dihydrofolate reductase from a facultative alkaliphilic and halotolerant bacillus strain
- Ist Teil von
- Extremophiles : life under extreme conditions, 2007-01, Vol.11 (1), p.75-83
- Ort / Verlag
- Heidelberg: Tokyo : Springer-Verlag
- Erscheinungsjahr
- 2007
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Elucidation of the molecular basis of the stability of enzymes from extremophilic organisms is of fundamental importance for various industrial applications. Due to the wealth of structural data from various species, dihydrofolate reductase (DHFR, EC 1.5.1.3) provides an excellent model for systematic investigations. In this report, DHFR from alkaliphilic Bacillus halodurans C-125 was cloned and expressed in E. coli. Functional analyses revealed that BhDHFR exhibits the most alkali-stable phenotype of DHFRs characterized so far. Optimal enzyme activity was observed in a slightly basic pH region ranging from 7.25 to 8.75. Alkali-stability is associated with a remarkable resistance to elevated temperatures (half-life of 60 min at 52.5°C) and to high concentrations of urea (up to 3 M). Although the secondary structure shows distinct similarities to those of mesophilic DHFR molecules, BhDHFR exhibits molecular features contributing to its alkaliphilic properties. Interestingly, the unique phenotype is diminished by C-terminal addition of a His-tag sequence. Therefore, His-tag-derivatized BhDHFR offers the opportunity to obtain deeper insights into the specific mechanisms of alkaliphilic adaption by comparison of the three dimensional structure of both BhDHFR molecules.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1431-0651eISSN: 1433-4909DOI: 10.1007/s00792-006-0013-6Titel-ID: cdi_proquest_miscellaneous_860371981
- Format
- –
- Schlagworte
- Adaptation, Physiological, Alkaliphily, Amino Acid Sequence, Bacillus, Bacillus - enzymology, Bacillus - genetics, Bacillus halodurans, Bacterial Proteins - chemistry, Bacterial Proteins - genetics, Bacterial Proteins - metabolism, Bacteriology, Biochemical characterization, Biological and medical sciences, Cloning, Cloning, Molecular, Conserved Sequence, Dihydrofolate reductase, Diyhdrofolate reductase, E coli, Enzymatic activity, Enzyme Stability, Escherichia coli, Fundamental and applied biological sciences. Psychology, High temperature, His-tag, Hydrogen-Ion Concentration, Kinetics, Metabolism. Enzymes, Microbiology, Molecular Sequence Data, Potassium Chloride - metabolism, Protein Structure, Secondary, Recombinant Proteins - metabolism, Sequence Alignment, Sequence Analysis, Protein, Sodium Chloride - metabolism, Space life sciences, Temperature, Tetrahydrofolate Dehydrogenase - chemistry, Tetrahydrofolate Dehydrogenase - genetics, Tetrahydrofolate Dehydrogenase - metabolism, thermal stability, Urea, Urea - metabolism