title: Purification and characterization of the Rieske iron-sulfur protein from the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius.
abstract: The previously detected Rieske iron-sulfur protein from the membranes of the thermoacidophile Sulfolobus acidocaldarius [Anemüller, S., et al. (1993) FEBS Lett. 318, 61-64] was purified to electrophoretic homogeneity and the N-terminal amino acids determined. The apparent molecular weight was estimated to be 32 kDa. The reduced protein displays a rhombic EPR spectrum with gxyz = 1.768, 1.895, 2.035. The average g-value of 1.902 is typical for nitrogen ligand-containing clusters. EPR spin quantification and the iron content indicate the presence of one [2Fe-2S] cluster. The purified protein displays ubiquinol cytochrome c reductase activity. The pH optimum of this reaction is temperature dependent and was determined to be pH 7 at 56 degrees C. The results presented in this study clearly prove that the Sulfolobus Rieske protein belongs to the family of the true Rieske iron-sulfur proteins.
authors.affiliation: Institut für Biochemie, Medizinische Universität zu Lübeck, Germany.
authors.forename: C L
authors.initials: CL
authors.lastname: Schmidt
authors.forename: S
authors.initials: S
authors.lastname: Anemüller
authors.forename: M
authors.initials: M
authors.lastname: Teixeira
authors.forename: G
authors.initials: G
authors.lastname: Schäfer
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification*; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D014450:Electron Transport Complex III / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D016945:Sulfolobus acidocaldarius / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; C037989:Rieske iron-sulfur protein; D014450:Electron Transport Complex III