Abstract
The gene encoding the non-heme iron-containing desulfoferrodoxin from Desulfovibrio vulgaris was cloned in two fragments in order to obtain polypeptides corresponding to the N- and C-terminal domains observed in the tertiary structure. These fragments were expressed in Escherichia coli, purified to homogeneity and biochemically and spectroscopically characterized. Both recombinant fragments behaved as independent metal-binding domains. The N-terminal fragment exhibited properties similar to desulforedoxin, as expected by the presence of a Fe(S-Cys)4 metal binding motif. The C-terminal fragment, which accommodates a Fe(N(ε)-His)3(N(δ)-His)(S-Cys) center, was shown to have properties similar to neelaredoxin, except for the reaction with superoxide. The activities of desulfoferrodoxin and of the expressed C-terminal fragment were tested with superoxide in the presence and absence of cytochrome c. The results are consistent with superoxide reductase activity and a possible explanation for the low superoxide consumption in the superoxide dismutase activity assays is proposed.
Original language | English |
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Pages (from-to) | 720-729 |
Number of pages | 10 |
Journal | Journal of Biological Inorganic Chemistry |
Volume | 5 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2000 |
Externally published | Yes |
Keywords
- Desulfoferrodoxin
- Desulforedoxin
- Neelaredoxin
- Rubredoxin
- Superoxide oxidoreductase