MUTATIONS IN THE PEPTIDYL TRANSFERASE REGION OF ESCHERICHIA-COLI 23S RIBOSOMAL-RNA AFFECTING TRANSLATIONAL ACCURACY
MUTATIONS IN THE PEPTIDYL TRANSFERASE REGION OF ESCHERICHIA-COLI 23S RIBOSOMAL-RNA AFFECTING TRANSLATIONAL ACCURACY
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DOI：
10.1093/nar/22.3.279
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发表时间：
1994-02-11
影响因子：
14.9
通讯作者：
DAHLBERG, AE
中科院分区：
文献类型：
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作者：
GREGORY, ST;LIEBERMAN, KR;DAHLBERG, AE
我们已经在克隆的大肠杆菌23 S rRNA基因的位置G2252和G2253产生突变。这些位点在化学足迹研究中受到P位点结合的tRNA的3'末端CCA的保护。在每个位置引入了三个可能的碱基变化，并且突变对生长速率和翻译准确性产生了一系列影响。在2252处携带突变的细胞的生长严重受损，而在2253处导致生长速率显著降低的唯一突变是G至C颠换。大多数突变影响翻译准确性，导致UGA、UAG和UAA无义突变的通读增加，以及体内lacZ报告基因的+1和-1移码。C2253被证明是一个UGA无义突变的抑制基因，在密码子243的trpA基因。还发现C2253突变与编码限制性形式的核糖体蛋白S12的rpsL等位基因不相互作用。这些结果提供了进一步的证据表明，定位于50 S核糖体亚基中的P位点的核苷酸影响核糖体A位点中的解码的准确性。
We have produced mutations in a cloned Escherichia coli 23S rRNA gene at positions G2252 and G2253. These sites are protected in chemical footprinting studies by the 3' terminal CCA of P site-bound tRNA. Three possible base changes were introduced at each position and the mutations produced a range of effects on growth rate and translational accuracy. Growth of cells bearing mutations at 2252 was severely compromised while the only mutation at 2253 causing a marked reduction in growth rate was a G to C transversion. Most of the mutations affected translational accuracy, causing increased readthrough of UGA, UAG and UAA nonsense mutations as well as +1 and -1 frameshifting in a lacZ reporter gene in vivo. C2253 was shown to act as a suppressor of a UGA nonsense mutation at codon 243 of the trpA gene. The C2253 mutation was also found not to interact with alleles of rpsL coding for restrictive forms of ribosomal protein S12. These results provide further evidence that nucleotides localized to the P site in the 50S ribosomal subunit influence the accuracy of decoding in the ribosomal A site.