Deutch C E, Soffer R L
Proc Natl Acad Sci U S A. 1975 Jan;72(1):405-8. doi: 10.1073/pnas.72.1.405.
A mutant of Escherichia coli lacking leucyl,phenylalanyl-tRNA:protein leucyltransferase, EC 2.3.2.6) exhibited several abnormal growth characteristics relative to the wild type or a revertant when grown with glycerol as a carbon source. All three strains were auxotrophic for proline. The mutant required higher levels of this amino acid than did the other strains to attain a normal growth yield and metabolized exogenous [14C]proline more rapidly. The greater rate of proline utilization was associated with a 4-fold increase in specific activity of proline oxidase. When glucose rather than glycerol was employed as a carbon source, proline oxidase activity was reduced by catabolite repression and the growth ccharacteristics of the mutant were similar to those of the parental and revertant strains. These results suggest that the mutant growth phenotype is due to an altered rate of proline catabolism and constitue evidence for regulation of a specific metabolic pathway by leucyl,phenylalanyl-tRNA-protein transferase.
一株缺乏亮氨酰 - 苯丙氨酰 - tRNA：蛋白质亮氨酰转移酶（EC 2.3.2.6）的大肠杆菌突变体，当以甘油作为碳源培养时，相对于野生型或回复突变体表现出几种异常的生长特性。这三种菌株对脯氨酸均为营养缺陷型。与其他菌株相比，该突变体需要更高水平的这种氨基酸才能达到正常的生长产量，并且能更快速地代谢外源[14C]脯氨酸。脯氨酸利用率的提高与脯氨酸氧化酶的比活性增加4倍有关。当使用葡萄糖而非甘油作为碳源时，脯氨酸氧化酶活性受到分解代谢物阻遏的抑制，该突变体的生长特性与亲本菌株和回复突变体相似。这些结果表明，突变体的生长表型是由于脯氨酸分解代谢速率的改变，并且构成了亮氨酰 - 苯丙氨酰 - tRNA - 蛋白质转移酶对特定代谢途径进行调控的证据。
