Conversion of 48S translation preinitiation complexes into 80S initiation complexes as revealed by toeprinting
Conversion of 48S translation preinitiation complexes into 80S initiation complexes as revealed by toeprinting
复制标题
DOI：
10.1016/s0014-5793(02)03776-6
复制
发表时间：
2003-01-02
期刊：
影响因子：
3.5
通讯作者：
Shatsky, IN
中科院分区：
文献类型：
--
作者：
Dmitriev, SE;Pisarev, AV;Shatsky, IN
利用趾印法分析翻译起始复合物的方法在研究真核生物翻译起始的分子机制方面得到了广泛的应用。到目前为止，当研究人员不打算区分48 S和80 S翻译起始复合物的趾纹模式时，使用了这种非常富有成效的方法。在这里，使用帽依赖性和内部核糖体进入位点（IRES）依赖性的mRNA，我们表明，48 S和80 S复合物的足印模式是不同的复合物是否组装在兔网织红细胞裂解液或从完全纯化的单个组件。这一观察结果使我们首次证明了β-珠蛋白和脑心肌炎病毒（EMCV）RNA的48 S复合物转化为80 S复合物的延迟，并评估了一些80 S抗生素阻断多肽延伸的潜力。此外，在40 S核糖体亚基定位起始密码子之后的步骤中，在EMCV IRES之后的三个连续AUC中显示了对真实起始密码子的额外选择。(C)2002年由Elsevier Science B. V.代表欧洲生物化学学会联合会出版。
A method of analysis of translation initiation complexes by toeprinting has recently acquired a wide application to investigate molecular mechanisms of translation initiation in eukaryotes. So far, this very fruitful approach was used when researchers did not aim to discriminate between patterns of toeprints for 48S and 80S translation initiation complexes. Here, using cap-dependent and internal ribosomal entry site (IRES)-dependent mRNAs, we show that the toeprint patterns for 48S and 80S complexes are distinct whether the complexes are assembled in rabbit reticulocyte lysate or from fully purified individual components. This observation allowed us to demonstrate for the first time a delay in the conversion of the 48S complex into the 80S complex for beta-globin and encephalomyocarditis virus (EMCV) RNAs, and to assess the potential of some 80S antibiotics to block polypeptide elongation. Besides, additional selection of the authentic initiation codon among three consecutive AUGs that follow the EMCV IRES was revealed at steps subsequent to the location of the initiation codon by the 40S ribosomal subunit. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.