Varenne S, Cavard D, Lazdunski C
Eur J Biochem. 1981 Jun 1;116(3):615-20. doi: 10.1111/j.1432-1033.1981.tb05380.x.
Synthesis of colicin A after induction with mitomycin C was studied. Specific inhibition of chromosomal protein synthesis occurred very shortly after mitomycin addition. There was no coordinate synthesis of colicin A (61000 Mr) and low-molecular-weight protein. Free and membrane-bound polysome fractions were isolated from cells induced with mitomycin C. Colicin A is synthesized in vitro in the free polysomes and not in the membrane-bound polysomes. Conditions are described which allow a practically specific labelling of colicin A in vivo. By using this system it was possible to demonstrate that colicin A is not transferred cotranslationally across the cytoplasmic membrane. In contrast, this protein leaves the cell where it was made long after synthesis. Preliminary evidence, suggesting that pauses occur during synthesis of colicin A, is presented.
研究了用丝裂霉素C诱导后大肠杆菌素A的合成。在添加丝裂霉素后不久就发生了对染色体蛋白质合成的特异性抑制。大肠杆菌素A（61000 Mr）和低分子量蛋白质没有协同合成。从用丝裂霉素C诱导的细胞中分离出游离和膜结合的多核糖体部分。大肠杆菌素A在游离多核糖体中而不是在膜结合多核糖体中进行体外合成。描述了在体内对大肠杆菌素A进行几乎特异性标记的条件。通过使用该系统，有可能证明大肠杆菌素A不是共翻译转运穿过细胞质膜的。相反，这种蛋白质在合成后很长时间才离开其产生的细胞。提出了表明在大肠杆菌素A合成过程中发生停顿的初步证据。
