Functions of the 3' and 5' genome RNA regions of members of the genus Flavivirus.
Functions of the 3' and 5' genome RNA regions of members of the genus Flavivirus.
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DOI：
10.1016/j.virusres.2015.02.006
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发表时间：
2015-08-03
期刊：
影响因子：
5
通讯作者：
Basu M
中科院分区：
文献类型：
--
作者：
Brinton MA;Basu M
黄病毒科黄病毒属成员的正义基因组长度约为11 kb nt，具有5′端I型帽，但无3′端poly A。5′和3′末端区域含有短的保守序列，这些序列被认为是古老序列的重复残余。然而，这些保守序列中的大多数的功能尚未确定。基因组的末端区域也包含多个保守的RNA结构。已经获得了许多这些结构的功能数据。三组互补的3′和5′末端区域序列，其中一些位于保守的RNA结构中，相互作用形成一个锅柄结构，该结构是启动负链RNA合成所需的，5′末端结构起启动子的作用。从末端RNA结构碱基配对到长距离RNA-RNA相互作用的转换是如何触发和调节的还不清楚，但有证据表明，与3′末端RNA结构上的三个位点结合的细胞蛋白和3′末端结构中的顺式作用亚稳3′ RNA元件参与其中。细胞蛋白也可能参与促进感染周期后期复制囊泡内新生基因组RNA的指数复制。在5′和3′末端区域的其他保守RNA结构和/或序列已被提出来调节基因组翻译。5′和3′末端序列的其他功能也有报道。
The positive sense genomes of members of the genus Flavivirus in the family Flaviviridae are ~11 kb nts in length and have a 5′ type I cap but no 3′ poly A. The 5′ and 3′ terminal regions contain short conserved sequences that are proposed to be repeated remnants of an ancient sequence. However, the functions of most of these conserved sequences have not yet been determined. The terminal regions of the genome also contain multiple conserved RNA structures. Functional data for many of these structures has been obtained. Three sets of complementary 3′ and 5′ terminal region sequences, some of which are located in conserved RNA structures, interact to form a panhandle structure that is required for initiation of minus strand RNA synthesis with the 5′ terminal structure functioning as the promoter. How the switch from the terminal RNA structure base pairing to the long distance RNA-RNA interaction is triggered and regulated is not well understood but evidence suggests involvement of a cell protein binding to three sites on the 3′ terminal RNA structures and a cis-acting metastable 3′ RNA element in the 3′ terminal structure. Cell proteins may also be involved in facilitating exponential replication of nascent genomic RNA within replication vesicles at later times of infection cycle. Other conserved RNA structures and/or sequences in the 5′ and 3′ terminal regions have been proposed to regulate genome translation. Additional functions of the 5′ and 3′ terminal sequences have also been reported.