Ephrati-Elizur E, Luther-Davies S
Mol Gen Genet. 1981;181(3):390-4. doi: 10.1007/BF00425617.
A group of mutants isolated from E coli K12(tif-1) display a very pleiotropic phenotype. The main characteristic of these mutants, temporarily designated 'S' strains, is their ability to suppress a large number of mutations. High efficiency of suppression is correlated with increased thermolability of cellular proteins, indicating an impairment in the fidelity of protein synthesis. Efficient suppression is also accompanied by the appearance of new characteristics like simultaneous resistance to several antibiotic drugs (Sm, Spc, and Mer), and plasmid-like DNA circles. Genetic studies show that the suppressor character is located in the rpoBC region. In a large number of spontaneous Rifr mutants, isolated from these strains, suppression or resistance to drugs is lost. The findings suggest that the phenotype of 'S' strains is due to an altered RNA polymerase causing erroneous transcription.
从大肠杆菌K12（tif-1）中分离出的一组突变体表现出非常多效的表型。这些突变体（暂时命名为“S”菌株）的主要特征是它们能够抑制大量突变。抑制效率高与细胞蛋白质热稳定性增加相关，表明蛋白质合成保真度受损。高效抑制还伴随着新特性的出现，如对几种抗生素药物（链霉素、壮观霉素和汞剂）同时耐药，以及出现质粒样DNA环。遗传学研究表明，抑制特性位于rpoBC区域。从这些菌株中分离出的大量自发利福平抗性突变体中，抑制或耐药性丧失。这些发现表明，“S”菌株的表型是由于RNA聚合酶改变导致错误转录所致。
