title: An investigation of the iron-sulphur proteins of benzene dioxygenase from Pseudomonas putida by electron-spin-resonance spectroscopy.
abstract: Benzene dioxygenase from Pseudomonas putida comprises three components, namely a flavoprotein (NADH:ferredoxin oxidoreductase; Mr 81000), an intermediate electron-transfer protein, or ferredoxin (Mr 12000) with a [2Fe-2S] cluster, and a terminal dioxygenase containing two [2Fe-2S] iron-sulphur clusters (Mr 215000), which requires two additional Fe2+ atoms/molecule for oxygenase activity. The ferredoxin and the dioxygenase give e.s.r. signals in the reduced state with rhombic symmetry and average g values of 1.92 and 1.896 respectively. The mid-point redox potentials were determined by e.s.r. titration at pH 7.0 to be -155 mV and -112 mV respectively. The signal from the dioxygenase shows pronounced g anisotropy and most closely resembles those of 4-methoxybenzoate mono-oxygenase from Pseudomonas putida and the [2Fe-2S] 'Rieske' proteins of the quinone-cytochrome c region of electron-transport chains of respiration and photosynthesis.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation / Q000187:drug effects; D005288:Ferredoxins; D007501:Iron / Q000494:pharmacology; D007506:Iron-Sulfur Proteins / Q000032:analysis*; D008667:Metalloproteins / Q000032:analysis*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009243:NAD / Q000494:pharmacology; D010084:Oxidation-Reduction; D011549:Pseudomonas / Q000201:enzymology*; D014461:Ultracentrifugation
chemical_list: D005288:Ferredoxins; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D009243:NAD; D007501:Iron; D006899:Mixed Function Oxygenases; C019765:benzene 1,2-dioxygenase