Overexpression, Isolation, and Spectroscopic Characterization of the Bidirectional [NiFe] Hydrogenase from Synechocystis sp. PCC 6803
| Autor: | Friedhelm Lendzian, Frauke Germer, Rüdiger Schulz, Ingo Zebger, Miguel Saggu, Jens Appel |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Hydrogenase
Stereochemistry Iron Mutant Gene Expression Biochemistry Redox Bacterial Proteins Affinity chromatography Nickel Spectroscopy Fourier Transform Infrared Nostoc Molecular Biology chemistry.chemical_classification Enzyme Catalysis and Regulation biology Chemistry Synechocystis Electron Spin Resonance Spectroscopy Wild type Active site Cell Biology biology.organism_classification Enzyme Activation Enzyme biology.protein Oxidation-Reduction NADP |
| Zdroj: | Journal of Biological Chemistry. 284:36462-36472 |
| ISSN: | 0021-9258 |
| Popis: | The bidirectional [NiFe] hydrogenase of the cyanobacterium Synechocystis sp. PCC 6803 was purified to apparent homogeneity by a single affinity chromatography step using a Synechocystis mutant with a Strep-tag II fused to the C terminus of HoxF. To increase the yield of purified enzyme and to test its overexpression capacity in Synechocystis the psbAII promoter was inserted upstream of the hoxE gene. In addition, the accessory genes (hypF, C, D, E, A, and B) from Nostoc sp. PCC 7120 were expressed under control of the psbAII promoter. The respective strains show higher hydrogenase activities compared with the wild type. For the first time a Fourier transform infrared (FTIR) spectroscopic characterization of a [NiFe] hydrogenase from an oxygenic phototroph is presented, revealing that two cyanides and one carbon monoxide coordinate the iron of the active site. At least four different redox states of the active site were detected during the reversible activation/inactivation. Although these states appear similar to those observed in standard [NiFe] hydrogenases, no paramagnetic nickel state could be detected in the fully oxidized and reduced forms. Electron paramagnetic resonance spectroscopy confirms the presence of several iron-sulfur clusters after reductive activation. One [4Fe4S](+) and at least one [2Fe2S](+) cluster could be identified. Catalytic amounts of NADH or NADPH are sufficient to activate the reaction of this enzyme with hydrogen. |
| Databáze: | OpenAIRE |
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