Publications

• Purification and properties of two 2-oxoacid:ferredoxin oxidoreductases from Halobacterium halobium.

  Kerscher L., Oesterhelt D.

  Pyruvate:ferredoxin oxidoreductase and 2-oxoglutarate:ferredoxin oxidoreductase were obtained from cell-free extracts of Halobacterium halobium as homogeneous proteins after ammonium sulfate precipitation, salting-out chromatography with ammonium sulfate on unsubstituted agarose, gel filtration an ... >> More

  Pyruvate:ferredoxin oxidoreductase and 2-oxoglutarate:ferredoxin oxidoreductase were obtained from cell-free extracts of Halobacterium halobium as homogeneous proteins after ammonium sulfate precipitation, salting-out chromatography with ammonium sulfate on unsubstituted agarose, gel filtration and chromatography on hydroxyapatite. The respective molecular weights are 256000 and 248000. Both enzymes consist of two sets of non-identical subunits of Mr 86000 and 42000 in the case of the pyruvate-degrading enzyme and of 88000 and 36000 in the case of the 20 -oxogluatarate-degrading enzyme. Analyses indicate that an intact enzyme molecule contains two [4 Fe-4S]2 + (2 + , 1+) clusters and two molecules of thiamin diphosphate. Flavin nucleotides, lipoic acid and pantetheine are absent. Thus the enzymes are very similar to the 2-oxoacid:ferredoxin oxidoreductases from fermentative and photosynthetic anaerobes described previously, but are clearly different from the 2-oxoacid dehydrogenase multienzyme complexes which commonly occur in anaerobic organisms. << Less

  Eur J Biochem 116:587-594(1981) [PubMed] [EuropePMC]

• 2-oxoacid:ferredoxin oxidoreductase from the thermoacidophilic archaeon, Sulfolobus sp. strain 7.

  Zhang Q., Iwasaki T., Wakagi T., Oshima T.

  The purified 2-oxoacid:ferredoxin oxidoreductase of a thermoacidophilic and aerobic crenarchaeote, Sulfolobus sp. strain 7, consists of 70-kDa alpha and 37-kDa beta subunits, and contains one thiamine pyrophosphate (TPP), one [4Fe-4S]2+.1+ cluster, and two magnesium atoms per alpha beta structure. ... >> More

  The purified 2-oxoacid:ferredoxin oxidoreductase of a thermoacidophilic and aerobic crenarchaeote, Sulfolobus sp. strain 7, consists of 70-kDa alpha and 37-kDa beta subunits, and contains one thiamine pyrophosphate (TPP), one [4Fe-4S]2+.1+ cluster, and two magnesium atoms per alpha beta structure. It exhibits a broad substrate specificity toward 2-oxoacids such as 2-oxoglutarate, 2-oxobutyrate, and pyruvate. The gene encoding the archaeal oxidoreductase was cloned, and the two open reading frames encoding the alpha (632 amino acids) and beta subunits (305 amino acids), respectively, were sequenced. Careful sequence alignment revealed several consensus motifs of this enzyme family, as well as possible cofactor binding residues of the Sulfolobus enzyme. This new structural information also indicates that (i) several genetic fusions and reorganization of the early, possibly alpha beta gamma delta-type enzyme similar to those from hyperthermophiles have taken place during evolution of the 2-oxoacid:ferredoxin (flavodoxin) oxidoreductase superfamily, which might have occurred in different ways in early aerobic archaea and early anaerobic bacteria, and that (ii) enzymes with different subunit compositions should have an essentially similar catalytic mechanism with one TPP and at least one [4Fe-4S] cluster as the minimal set of redox centers. << Less

  J. Biochem. 120:587-599(1996) [PubMed] [EuropePMC]