Diaz I, Ehrenberg M, Kurland C G
Mol Gen Genet. 1986 Feb;202(2):207-11. doi: 10.1007/BF00331638.
Petrullo et al. (1983) have studied the consequences of combining a mutation (rpsL-) that normally generates streptomycin resistant (Smr) ribosomes with a mutation (miaA-) that leads to loss of a tRNA hypermodification. They found surprisingly that such doubly mutant bacteria become streptomycin dependent (Smd). Here, we show in vitro that ribosomes purified from an Smr mutant behave very like Smd ribosomes when they are combined with tRNA from an miaA- mutant. Our analysis suggests that proofreading becomes excessively intense when the mutant components are combined, and that this reduces the efficiency of translation to the very low levels characteristic of Smd ribosomes. We show that Sm increases the efficiency of translation in vitro by suppressing the proofreading flows. We suggest that this will explain the growth stimulatory effect of Sm on the rpsL-, miaA- double mutants.
彼得鲁洛等人（1983年）研究了将通常产生链霉素抗性（Smr）核糖体的突变（rpsL-）与导致tRNA超修饰缺失的突变（miaA-）相结合的后果。他们令人惊讶地发现，这种双突变细菌变成了链霉素依赖性（Smd）。在此，我们在体外表明，从Smr突变体中纯化的核糖体与来自miaA-突变体的tRNA结合时，其行为与Smd核糖体非常相似。我们的分析表明，当突变成分结合时，校对变得过于强烈，这将翻译效率降低到Smd核糖体特有的极低水平。我们表明，链霉素通过抑制校对流程来提高体外翻译效率。我们认为，这将解释链霉素对rpsL-、miaA-双突变体的生长刺激作用。
