De Wilde M, Cabezón T, Villarroel R, Herzog A, Bollen A
Mol Gen Genet. 1975 Dec 23;142(1):19-33. doi: 10.1007/BF00268752.
Two spontaneous mutants of Escherichia coli strain KMBL-146 selected for resistance to the aminoglycoside antibiotic neamine show severe restriction of amber suppressors in vivo. Purified ribosomes from the mutant strains exhibit low neamine-induced misreading in vitro and a decreased affinity for the related antibiotic streptomycin. Biochemical analysis shows that the mutants each have two modified 30S ribosmal proteins, S12 and S5. In agreement with these results, genetic analysis shows that two mutations are present, neither of which confers resistance to neamine by itself; the mutation located in gene rpxL (the structural gene for protein S12) confers streptomycin dependence but this dependence is suppressed in the presence of the second mutation, located in gene rpxE (the structural gene for protein S5).
从大肠杆菌KMBL - 146菌株中筛选出的对氨基糖苷类抗生素新霉素具有抗性的两个自发突变体，在体内表现出对琥珀抑制子的严重限制。从突变菌株中纯化的核糖体在体外表现出低水平的新霉素诱导的错读，并且对相关抗生素链霉素的亲和力降低。生化分析表明，每个突变体都有两种修饰的30S核糖体蛋白，即S12和S5。与这些结果一致，遗传分析表明存在两个突变，其中任何一个突变本身都不会赋予对新霉素的抗性；位于基因rpxL（蛋白S12的结构基因）中的突变赋予链霉素依赖性，但在位于基因rpxE（蛋白S5的结构基因）中的第二个突变存在时，这种依赖性会被抑制。
