Aspartate biosynthesis

The biosynthesis of aspartate is an interface between amino acid metabolism and carbohydrate metabolism. Aspartate is synthesized through a transamination reaction between oxaloacetate, an important Krebs cycle intermediate, and glutamate, an amino acid. Here, aspartate aminotransferase catalyzes the reversible transfer of an amino group from glutamate to oxaloacetate, forming -ketoglutarate and aspartate. Yeast aspartate aminotransferase is encoded by AAT1 and AAT2. Aat1p localizes to mitochondria and may be involved in a putative malate-aspartate shuttle, while Aat2p localizes to the cytosol and is required for growth on minimal media lacking aspartate. Aspartate, in addition to its role as a proteinogenic amino acid, is a substrate in the arginine biosynthesis pathway and a precursor to the aspartate family amino acids methionine, isoleucine, asparagine, and threonine in S. cerevisiae. Source: https://pathway.yeastgenome.org/

天冬氨酸的生物合成是氨基酸代谢与碳水化合物代谢之间的交汇点。天冬氨酸通过草酰乙酸（Krebs循环的重要中间体）与谷氨酸之间的转氨基反应而合成。在此过程中，天冬氨酸氨基转移酶催化氨基酸基团从谷氨酸向草酰乙酸的可逆转移，从而形成-酮戊二酸和天冬氨酸。酵母中的天冬氨酸氨基转移酶由AAT1和AAT2编码。Aat1p定位于线粒体，可能与假定的苹果酸-天冬氨酸穿梭作用相关，而Aat2p定位于细胞质，对于在缺乏天冬氨酸的最小培养基上生长是必需的。除了作为蛋白质合成氨基酸的作用外，天冬氨酸还是精氨酸生物合成途径的底物，以及啤酒酵母中天冬氨酸族氨基酸甲硫氨酸、异亮氨酸、天冬酰胺和苏氨酸的前体。来源：https://pathway.yeastgenome.org/