Abstract:
The bacterial ribosomal 5S rRNA-binding protein L5 is universally conserved (uL5). It contains the so-called P-site loop (PSL), which contacts the P-site tRNA in the ribosome. Certain PSL mutations in yeast are lethal, suggesting that the loop plays an important role in translation. In this work, for the first time, a viable Escherichia coli strain was obtained with the deletion of the major part of the PSL (residues 73-80) of the uL5 protein. The deletion conferred cold sensitivity and drastically reduced the growth rate and overall protein synthesizing capacity of the mutant. Translation rate is decreased in mutant cells as compared to the control. At the same time, the deletion causes increased levels of -1 frameshifting and readthrough of all three stop codons. In general, the results show that the PSL of the uL5 is required for maintaining both the accuracy and rate of protein synthesis in vivo.
摘要:
细菌核糖体5SrRNA结合蛋白L5是普遍保守的(uL5)。它包含所谓的P位点环(PSL),接触核糖体中的P位点tRNA。酵母中的某些PSL突变是致命的,这表明循环在翻译中起着重要的作用。在这项工作中,第一次,获得了可行的大肠杆菌菌株,其中删除了uL5蛋白的PSL的主要部分(残基73-80)。缺失赋予了冷敏感性,并大大降低了突变体的生长速率和整体蛋白质合成能力。与对照相比,突变细胞中的翻译速率降低。同时,缺失导致所有三个终止密码子的-1移码和连读水平增加。总的来说,结果表明,uL5的PSL是维持体内蛋白质合成的准确性和速率所必需的。