真核生物 mRNA 的起始序列可以同时与起始 80S 核糖体和 40S 核糖体亚基结合。

Leader sequences of eukaryotic mRNA can be simultaneously bound to initiating 80S ribosome and 40S ribosomal subunit.

机构信息

Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.

出版信息

Biochemistry (Mosc). 2012 Apr;77(4):342-5. doi: 10.1134/S0006297912040049.

DOI:10.1134/S0006297912040049

Abstract

Binding of mRNA leader sequences to ribosomes was studied in conditions of a cell-free translation system based on wheat germ extract. Leader sequence of TMV mRNA (the so-called omega-RNA sequence) was able to bind simultaneously 80S ribosome and 40S ribosomal subunit. It was found that nucleotide substitutions in omega-RNA resulting in destabilization of RNA structure have no effect on the complex formation with both 80S ribosome and 40S ribosomal subunit. Leader sequence of globin mRNA is also able to form a similar joint complex. It is supposed that the ability of mRNA leader sequences to bind simultaneously 80S ribosome and 40S subunit is independent of leader nature and may reflect previously unknown eukaryotic mechanisms of translation initiation.

摘要

在基于麦胚提取物的无细胞翻译系统中研究了 mRNA 前导序列与核糖体的结合。TMV mRNA 的前导序列（所谓的 ω-RNA 序列）能够同时结合 80S 核糖体和 40S 核糖体亚基。研究发现，导致 RNA 结构不稳定的 ω-RNA 核苷酸取代对与 80S 核糖体和 40S 核糖体亚基形成复合物没有影响。珠蛋白 mRNA 的前导序列也能够形成类似的联合复合物。据推测，mRNA 前导序列同时与 80S 核糖体和 40S 亚基结合的能力与前导序列的性质无关，可能反映了以前未知的真核翻译起始机制。