The phosphoenolpyruvate-pyruvate-oxaloacetate node is a major branch within the central carbon metabolism and acts as a connection point between glycolysis, gluconeogenesis, and the TCA cycle. Phosphoenolpyruvate carboxylase, pyruvate carboxylase, phosphoenolpyruvate carboxykinase, malic enzymes, and pyruvate kinase, among others, are enzymes included in this node. We determined the mRNA levels and specific activity profiles of some of these genes and enzymes in Streptomyces coelicolor M-145. The results obtained in the presence of glucose demonstrated that all genes studied of the phosphoenolpyruvate-pyruvate-oxaloacetate node were expressed, although at different levels, with 10- to 100-fold differences. SCO3127 (phosphoenolpyruvate carboxylase gene) and SCO5261 (NADP⁺-dependent malic enzyme gene) showed the highest expression in the rapid growth phase, and the mRNA levels corresponding to SCO5896 (phosphoenolpyruvate-utilizing enzyme gene), and SCO0546 (pyruvate carboxylase gene) increased 5- to 10-fold towards the stationary phase. In casamino acids, in general mRNA levels of S. coelicolor were lower than in glucose, however, results showed greater mRNA expression of SCO4979 (PEP carboxykinase), SCO0208 (pyruvate phosphate dikinase gene), and SCO5261 (NADP⁺-dependent malic enzyme). These results suggest that PEP carboxylase (SCO3127) is an important enzyme during glucose catabolism and oxaloacetate replenishment. On the other hand, phosphoenolpyruvate carboxykinase, pyruvate phosphate dikinase, and NADP⁺-malic enzyme could have an important role in gluconeogenesis in S. coelicolor.

中文翻译：

---

链霉菌M-145链霉菌中的磷酸烯醇丙酮酸-丙酮酸-草酰乙酸节点基因和酶。

磷酸烯醇丙酮酸-丙酮酸-草酰乙酸节点是中央碳代谢内的主要分支，并充当糖酵解，糖异生和TCA循环之间的连接点。磷酸烯醇丙酮酸羧化酶，丙酮酸羧化酶，磷酸烯醇丙酮酸羧化激酶，苹果酸酶和丙酮酸激酶等是该节点中包括的酶。我们确定了链霉菌M-145中某些基因和酶的mRNA水平和比活性谱。在葡萄糖存在下获得的结果表明，磷酸烯醇丙酮酸-丙酮酸-草酰乙酸节点的所有研究基因均被表达，尽管其水平不同，但差异为10至100倍。SCO3127（磷酸烯醇丙酮酸羧化酶基因）和SCO5261（NADP ⁺依赖的苹果酸酶基因）在快速生长阶段表达最高，并且对应于SCO5896（利用磷酸烯醇丙酮酸的酶基因）和SCO0546（丙酮酸羧化酶基因）的mRNA水平向固定相增加5至10倍。在酪蛋白氨基酸中，一般而言，天蓝色链霉菌的mRNA水平低于葡萄糖，但是，结果显示SCO4979（PEP羧激酶），SCO0208（丙酮酸磷酸二激酶基因）和SCO5261（NADP ⁺依赖性苹果酸酶）的mRNA表达更高。。这些结果表明，PEP羧化酶（SCO3127）是葡萄糖分解代谢和草酰乙酸补充过程中的重要酶。另一方面，磷酸烯醇丙酮酸羧激酶，丙酮酸磷酸二激酶和NADP ⁺-苹果酸酶可能在天蓝色链霉菌的糖异生中起重要作用。