The glutamate metabolism in S. cerevisiae happens both inside the mitochondria and the cytosol. The process in the mitochondria starts with asparagine being metabolized into ornithine. Ornithine then reacts with an ornithine aminotransferase resulting in the release of a L-glutamic gamma semialdehyde. This compound then reacts with an aldehyde dehydrogenase resulting in the release of L-glutamic acid. Mitochondrial L-glutamic acid is degraded by reacting with a glutamate dehydrogenase resulting in the release of oxoglutaric acid which is then incorporated into the TCA cycle. The process of glutamate metabolism in the cytosol starts with the synthesis of L-glutamic acid from either L-glutamine or from oxoglutaric acid. 1. L-glutamine reacts with Oxoglutaric acid through a NAD dependent glutamate synthase resulting in the release of glutamic acid 2. Oxoglutaric acid reacts with ammonium through a NADP dependent glutamate dehydrogenase resulting in the release of water and L-glutamic acid 3.Oxoglutaric acid reacts with ammonium through a NADP dependent glutamate dehydrogenase 2 resulting in the release of water and L-glutamic acid The degradation of L-glutamic acid starts with water through an glutamate dehydrogenase resulting in the release of Oxoglutaric acid and ammonium. L-glutamic acid can also be degraded by reacting with a glutamate decarboxylase resulting in the release of GABA. GABA is further degraded by 4-aminobutyrate aminotransferase resulting in the release of succinic acid semialdehyde.This compound is then metabolized into succinic acid through a succinate semialdehyde dehydrogenase

Glutamate Metabolism References