Kisumi M, Takagi T, Chibata I
J Biochem. 1978 Oct;84(4):881-90. doi: 10.1093/oxfordjournals.jbchem.a132200.
L-Arginine biosynthesis in Serratia marcescens Sr41 was found to be controlled by (a) feedback inhibition of N-acetylglutamate synthetase and (b) repression of some L-arginine biosynthetic enzymes, and an L-arginine-degrading system was found to exist. Accordingly, an L-arginine-producing mutant (aru argR argA) of S. marcescens Sr41 was constructed as follows. A mutant incapable of L-arginine utilization (aru) was obtained from the wild strain. Subsequently, from the lysine auxotroph (lysA) of aru mutant, a mutant having derepressed L-arginine biosynthetic enzymes (argR) was isolated by screening for colonies that could utilize Nalpha-acetyl-L-lysine in the presence of L-arginine. This selection was based on the finding that acetylornithinase of S. marcescens hydrolyzed Nalpha-acetyl-L-lysine. On the other hand, to obtain a mutant with feedback-resistant N-acetylglutamate synthetase (argA), the proAB argD argR triple mutant was isolated from the indirectly suppressed revertant (proAB argD) of the proline auxotroph (proAB). Next, the argA mutant was isolated from the triple mutant by selection for resistance to 3,4-dehydro-DL-proline in the presence of L-arginine. The argA mutation was introduced into the aru lysA argR strain by PS20-mediated cotransduction with lysA+. The aru argR argA lysA+ transductant produced 25 mg/ml of L-arginine in the medium.
已发现粘质沙雷氏菌Sr41中L-精氨酸的生物合成受（a）N-乙酰谷氨酸合成酶的反馈抑制和（b）一些L-精氨酸生物合成酶的阻遏控制，并且发现存在一个L-精氨酸降解系统。因此，如下构建了粘质沙雷氏菌Sr41的L-精氨酸生产突变体（aru argR argA）。从野生菌株中获得了一个不能利用L-精氨酸的突变体（aru）。随后，从aru突变体的赖氨酸营养缺陷型（lysA）中，通过筛选在L-精氨酸存在下能够利用Nα-乙酰-L-赖氨酸的菌落，分离出一个L-精氨酸生物合成酶去阻遏的突变体（argR）。这种选择基于粘质沙雷氏菌的乙酰鸟氨酸酶能水解Nα-乙酰-L-赖氨酸这一发现。另一方面，为了获得一个对N-乙酰谷氨酸合成酶具有反馈抗性的突变体（argA），从脯氨酸营养缺陷型（proAB）的间接抑制回复突变体（proAB argD）中分离出proAB argD argR三重突变体。接下来，在L-精氨酸存在下，通过选择对3,4-脱氢-DL-脯氨酸的抗性，从三重突变体中分离出argA突变体。通过PS20介导的与lysA +的共转导，将argA突变引入aru lysA argR菌株。aru argR argA lysA +转导子在培养基中产生25mg / ml的L-精氨酸。
