The [Ni-Fe] hydrogenase from the thermophilic bacterium Acetomicrobium flavidum
| Autor: | Giuliano Galli, Paola Pedroni, Guido Grandi, Claudio Pratesi, L. Serbolisca, G. M. Mura |
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| Rok vydání: | 1996 |
| Předmět: |
DNA
Bacterial Hydrogenase Protein Conformation Protein subunit Molecular Sequence Data Restriction Mapping Gene Expression Biology medicine.disease_cause Microbiology Bacteria Anaerobic Tetramer Enzyme Stability Escherichia coli medicine Amino Acid Sequence Cloning Molecular DNA Primers Thermophilic organism Base Sequence Molecular mass Thermophile Hydrogen-Ion Concentration Recombinant Proteins Molecular Weight Kinetics Biochemistry Genes Bacterial Protein quaternary structure Protein Processing Post-Translational |
| Zdroj: | Europe PubMed Central |
| ISSN: | 1465-2080 1350-0872 |
| DOI: | 10.1099/00221287-142-4-829 |
| Popis: | Biochemical analysis of the soluble hydrogenase from the thermophilic organism Acetomicrobium flavidum revealed that the enzyme is an a2ß2 tetramer, with the a and ß subunits having a molecular mass of 50 kDa and 25 kDa, respectively. The most important biochemical properties of the enzyme are a specific activity of 77 μmol min-1 (mg protein)-1 a K m for methylviologen of 0.2 mM, a pH optimum of 7.5 and a T 50 of about 70 †C. In addition, the enzyme is remarkably stable to oxygen inactivation, retaining full activity after 24 h exposure to air. By using oligodeoxynucleotides designed on the basis of the N-terminal sequences of the two subunits, the corresponding genes have been isolated and sequenced. When compared to the other hydrogenases so far characterized, the A. flavidum hydrogenase appears to be a typical [Ni-Fe] enzyme. The hydrogenase was expressed in Escherichia coli at high levels in a soluble form but it was not active. The analysis of the recombinant large subunit showed that it was not post-translationally processed at its C-terminus. |
| Databáze: | OpenAIRE |
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