Arkov A L, Mankin A, Murgola E J
Department of Molecular Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
J Bacteriol. 1998 May;180(10):2744-8. doi: 10.1128/JB.180.10.2744-2748.1998.
rRNA plays a central role in protein synthesis and is intimately involved in the initiation, elongation, and termination stages of translation. However, the mode of its participation in these reactions, particularly as to the decoding of genetic information, remains elusive. In this paper, we describe a new approach that allowed us to identify an rRNA segment whose function is likely to be related to translation termination. By screening an expression library of random rRNA fragments, we identified a fragment of the Escherichia coli 23S rRNA (nucleotides 74 to 136) whose expression caused readthrough of UGA nonsense mutations in certain codon contexts in vivo. The antisense RNA fragment produced a similar effect, but in neither case was readthrough of UAA or UAG observed. Since termination at UGA in E. coli specifically requires release factor 2 (RF2), our data suggest that the fragments interfere with RF2-dependent termination.
核糖体RNA（rRNA）在蛋白质合成中起核心作用，并密切参与翻译的起始、延伸和终止阶段。然而，其参与这些反应的方式，特别是在遗传信息解码方面，仍然难以捉摸。在本文中，我们描述了一种新方法，该方法使我们能够鉴定出一个rRNA片段，其功能可能与翻译终止有关。通过筛选随机rRNA片段的表达文库，我们鉴定出了大肠杆菌23S rRNA的一个片段（核苷酸74至136），其表达在体内某些密码子背景下导致UGA无义突变的通读。反义RNA片段产生了类似的效果，但在这两种情况下均未观察到UAA或UAG的通读。由于大肠杆菌中UGA处的终止特别需要释放因子2（RF2），我们的数据表明这些片段干扰了依赖RF2的终止。
