Goldemberg S H
Biochem J. 1984 Apr 1;219(1):205-10. doi: 10.1042/bj2190205.
Escherichia coli BGA8 , a mutant unable to synthesize putrescine, behaves as stringent or relaxed according to the presence or absence of polyamine, respectively, in the culture medium. The relaxed synthesis of RNA can be reverted back to stringent by addition of putrescine or spermidine. The stringent response depends on the concentration of the polyamine in the culture medium. The formation of guanosine 3'-diphosphate 5'-diphosphate elicited by amino acid starvation is stimulated at least 40-fold in putrescine-supplemented bacteria and only about 2-fold in putrescine-depleted cells.
大肠杆菌BGA8是一种无法合成腐胺的突变体,根据培养基中是否存在多胺,其表现为严谨型或松弛型。通过添加腐胺或亚精胺,RNA的松弛型合成可恢复为严谨型。严谨反应取决于培养基中多胺的浓度。在补充了腐胺的细菌中,由氨基酸饥饿引发的鸟苷3'-二磷酸5'-二磷酸的形成至少被刺激40倍,而在缺乏腐胺的细胞中仅被刺激约2倍。