Tabor C W, Tabor H, Hafner E W
J Biol Chem. 1978 May 25;253(10):3671-6.
Mutants of Escherichia coli deficient in adenosylmethionine decarboxylase, an enzyme in the biosynthetic pathway for spermidine, were isolated after mutagenesis of E. coli K 12 with N-methyl-N-nitro-N-nitrosoguanidine or with the bacteriophage Mu. The mutated gene, designated speD, is at 2.7 min on the E. coli chromosome map. In several of the mutants resulting from Mu insertion both adenosylmethionine decarboxylase activity and spermidine were undetectable. The absence of spermidine from speD strains proves the essential role of adenosylmethionine decarboxylase in the biosynthetic pathway for spermidine. Despite the complete absence of spermidine, these mutants grew at 75% of the wild type rate.
用N-甲基-N-硝基-N-亚硝基胍或噬菌体Mu对大肠杆菌K12进行诱变后，分离出了缺乏腺苷甲硫氨酸脱羧酶（一种参与亚精胺生物合成途径的酶）的大肠杆菌突变体。突变基因命名为speD，位于大肠杆菌染色体图谱的2.7分钟处。在一些由Mu插入产生的突变体中，腺苷甲硫氨酸脱羧酶活性和亚精胺均无法检测到。speD菌株中缺乏亚精胺证明了腺苷甲硫氨酸脱羧酶在亚精胺生物合成途径中的重要作用。尽管完全没有亚精胺，但这些突变体的生长速度为野生型的75%。
