Isaksson L A, Fodor K, Kirsebom L A, Bouadloun F, Murén E
Mol Gen Genet. 1980;180(1):27-33. doi: 10.1007/BF00267349.
The translational capacity in vitro in Escherichia coli, using RNA from phage R17 or Q beta as messenger, is several times higher if the extracts are prepared from cells harvested in early exponential phase or grown under conditions of good aeration compared to if extracts are prepared from cells harvested in a later growth phase or grown under semi-aerobic conditions. In low activity extracts the production of phage replicase protein is preferentially affected. Growth of a wild type strain under semi-aerobic conditions has a less pronounced effect on translational capacity in vitro using crude mRNA from normal or T4 infected cells or with poly(U). Mutants were fortuitously found which did not show a lowered translational activity in vitro as a result of entering late phase of growth. Two of these were changed in RNA polymerase. Two different translational inhibitors can be demonstrated in the ribosomal wash fraction obtained from semi-aerobically grown wild type cells, whereas only one was found in the case of aerobically grown cells. The low translational activity of semi-aerobically grown cells in vitro is implied to be dependent on the induction or activation of a translational inhibitor. It behaves like a protein but is not likely to be a protease or RNAse.
如果从处于指数生长期早期收获的细胞或在良好通气条件下培养的细胞中制备提取物，与从生长后期收获的细胞或在半需氧条件下培养的细胞中制备提取物相比，以噬菌体R17或Qβ的RNA作为信使在大肠杆菌中进行体外翻译能力要高出几倍。在低活性提取物中，噬菌体复制酶蛋白的产生受到优先影响。野生型菌株在半需氧条件下生长，对使用来自正常或T4感染细胞的粗mRNA或聚（U）进行体外翻译能力的影响较小。偶然发现了一些突变体，它们进入生长后期后体外翻译活性并未降低。其中两个突变体的RNA聚合酶发生了变化。从半需氧生长的野生型细胞获得的核糖体洗涤组分中可以证明有两种不同的翻译抑制剂，而在需氧生长细胞的情况下仅发现一种。半需氧生长细胞在体外的低翻译活性被认为取决于一种翻译抑制剂的诱导或激活。它表现得像一种蛋白质，但不太可能是蛋白酶或核糖核酸酶。
