Novel and remarkably thermostable ferredoxin from the hyperthermophilic archaebacterium Pyrococcus furiosus
- Univ. of Georgia, Athens (USA)
The archaebacterium Pyrococcus furiosus is a strict anaerobe that grows optimally at 100{degree}C by a fermentative-type metabolism in which H{sub 2} and CO{sub 2} are the only detectable products. A ferredoxin, which functions as the electron donor to the hydrogenase of this organism was purified under anaerobic reducing conditions. The study shows that P. furiosus ferredoxin is therefore distinct from other ferredoxins in that the bulk of its iron is not present as iron-sulfur clusters with an S = 1/2 ground state. The apoferredoxin was reconstituted with iron and sulfide to give a protein that was indistinguishable from the native ferredoxin by its iron content and electron paramagnetic resonance properties, which showed that the novel iron-sulfur clusters were not artifacts of purification. The reduced ferredoxin also functioned as an electron donor for H{sub 2} evolution catalyzed by the hydrogenase of the mesophilic eubacterium Clostridium pasteurianum. P. furiosus ferredoxin was resistant to denaturation by sodium dodecyl sulfate (20%, wt/vol) and was remarkably thermostable. Its UV-visible absorption spectrum and electron carrier activity to P. furiosus hydrogenase were unaffected by a 12-h incubation at 95{degree}C.
- DOE Contract Number:
- FG09-88ER13901
- OSTI ID:
- 6995392
- Journal Information:
- Journal of Bacteriology; (USA), Vol. 171:6; ISSN 0021-9193
- Country of Publication:
- United States
- Language:
- English
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