摘要
真核生物的起始复合物并不是在起始AUG处形成 ,而是在mRNA的 5′末端形成 ,其识别信号就是 5′末端的帽子结构。小RNA病毒科成员RNA 5′末端没有帽子结构 ,而有一个病毒编码的小蛋白质与基因组共价相连。小RNA病毒的蛋白翻译起始于 5′非翻译区中的内部顺式调控元件 ,称为内部核糖体进入位点 (IRES)。口蹄疫病毒 (foot and mouthdiseasevirus,FMDV)是该科病毒的典型代表 ,引起偶蹄动物的急性接触性传染病。完整FMDV含有单链正股RNA、衣壳蛋白及少量装配过程中夹带的非结构蛋白和宿主细胞肌动蛋白 ,其基因组RNA全长约 8 5kb ,可直接作为信使RNA。对IRES的一、二级结构进行了比较 。
Unlike most Eukaryotic mRNAs, FMDV RNA is not capped at 5′end but has a small viral coded protein (VPg) covalently attached to the terminal 5′uridine residue. Translation initiation of Picornavirus RNA is dependent on the presence of an internal ribosome entry site (IRES) element at the 5′end of genome RNA, and it is different from that of most eucaryotic cell that initiate at a cap element. Foot and Mouth disease virus (FMDV), a member of the genus Aphthoviridae of the Picornavirus family, cause a highly contagious viral disease of cloven hooved animals and it is of paramout economic importance. Entire viral particles are composed of a single stranded positive sense RNA about 8500 nucleotides (nt), capsid proteins and a little un structural proteins and actins carried secretly during encapsidation. Up to now, it has been testified that IRES is a unique element directing the translation initiation in FMDV RNA. The sequences and secondary structures of IRES are compared. Interaction between IRES and translation initiation factors and relation with virulence of FMDV is summarized.
出处
《中国生物工程杂志》
CAS
CSCD
2004年第6期6-11,共6页
China Biotechnology
基金
国家"973"计划资助项目 (G19990 1190 1)
