Catalytic Properties of Linoleate Diol Synthase of the Fungus Gaeumannomyces Graminis: A Comparison with PGH Synthases
The fungus Gaeumannomyces graminis causes “take-all”, a devastating root disease of wheat. Our interest in G. graminis is due to its biosynthesis of oxylipins, which might be important for its reprodution. The fungus can sequentially metabolize linoleic acid (18:2n-6) to 8R-hydroperoxylinoleic acid (8-HPODE) via an 8R-dioxygenase and to 7S,8S-dihydroxylinoleic acid (7,8-DiHODE) via a hydroperoxide isomerase1. A highly purified protein with both enzymes activities was recently found to be a hemoprotein2. The protein had an apparent molecular size of 130 kDa on SDA-PAGE and it appeared to be a tetramer on gel filtration. The holoprotein will be referred to as linoleate diol synthase (LDS).
KeywordsHigh Spin State Ribonucleotide Reductase Tyrosyl Radical Electron Spin Resonance Investigation Glycyl Radical
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