一段复杂的RNA序列决定脑心肌炎病毒RNA翻译的内部起始。

A complex RNA sequence determines the internal initiation of encephalomyocarditis virus RNA translation.

作者信息

Evstafieva A G, Ugarova T Y, Chernov B K, Shatsky I N

机构信息

A.N. Belosersky Laboratory, Moscow State University, USSR.

出版信息

Nucleic Acids Res. 1991 Feb 11;19(3):665-71. doi: 10.1093/nar/19.3.665.

Translation initiation on EMCV RNA occurs via binding of ribosomes to an internal sequence within the 5' noncoding region. To investigate the organization of the internal ribosome entry site (IRES) we have determined the translational efficiencies of a series of deletion mutants within the 5' noncoding region of EMCV RNA. Three functional regions have been distinguished: a sequence between nts 315-484 and the upper parts of the double-helical structural domains III (nts 488-647) and IV (nts 701-763). The first one greatly enhances translation, but is not absolutely necessary for internal initiation. The other two regions are indispensable to this process. A sequence within domain IV determines inhibition of in vitro translation of mRNAs with 5'-terminal dependent initiation. It is proposed to interact with a translational factor(s) common to the internal and 5'-terminal dependent initiation.

脑心肌炎病毒（EMCV）RNA的翻译起始是通过核糖体与5'非编码区内的一段内部序列结合来实现的。为了研究内部核糖体进入位点（IRES）的结构，我们测定了EMCV RNA 5'非编码区内一系列缺失突变体的翻译效率。已区分出三个功能区：核苷酸315 - 484之间的序列以及双螺旋结构域III（核苷酸488 - 647）和IV（核苷酸701 - 763）的上部。第一个功能区极大地增强了翻译，但对于内部起始并非绝对必需。另外两个区域对于这个过程是不可或缺的。结构域IV内的一个序列决定了对具有5'末端依赖性起始的mRNA体外翻译的抑制作用。有人提出它与内部起始和5'末端依赖性起始共有的一种翻译因子相互作用。