Molecular mechanism of pyruvate-ferredoxin oxidoreductases based on data obtained with the Clostridium pasteurianum enzyme.
Pyruvate-ferredoxin oxidoreductase oxidises pyruvate in many fermentative microorganisms. The enzyme from Clostridium pasteurianum is an air-sensitive homodimer of 2x120000 daltons, for which pyruvate is the best substrate found among several alpha-ketoacids. Each subunit contains eight iron atoms in two [4Fe-4S] clusters. Two distinct EPR signals, possibly associated with two ligand environments, arise from one of these clusters. Binding of pyruvate does not generate a radical. The results reported suggest a scheme for the electron flow in pyruvate ferredoxin oxidoreductases according to which the detailed reaction mechanism depends on the number (even or odd) of [4Fe-4S] clusters present in a given enzyme.
Moulis
J M
JM
CEA Département de Biologie Moléculaire et Structurale, Laboratoire des Métalloprotéines, Grenoble, France.
Davasse
V
V
Meyer
J
J
Gaillard
J
J
D002384:Catalysis; D003013:Clostridium / Q000201:enzymology*; D004227:Dithionite / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D007658:Ketone Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances; D008970:Molecular Weight; D050743:Pyruvate Synthase; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid
D007506:Iron-Sulfur Proteins; D046911:Macromolecular Substances; D011773:Pyruvates; D004227:Dithionite; D019289:Pyruvic Acid; D007501:Iron; D007658:Ketone Oxidoreductases; D050743:Pyruvate Synthase