Functional analysis of structural motifs in dicistroviruses
Functional analysis of structural motifs in dicistroviruses
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DOI:
10.1016/j.virusres.2008.06.006
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发表时间:
2009-02-01
期刊:
影响因子:
5
通讯作者:
Uchiumi, Toshio
中科院分区:
文献类型:
--
作者:
Nakashima, Nobuhiko;Uchiumi, Toshio
The family Dicistroviridae is composed of positive-stranded RNA viruses which have monopartite genomes. These viruses carry genome-linked virus proteins (VPg)and poly (A) tails. The 5' untranslated region(UTR) is approximately 500 nucleotides and contains an internal ribosome entry site (IRES). These features resemble those of vertebrate picornaviruses, but dicistroviruses have other distinct characteristics. Picornaviruses have a single large open reading frame (ORF) encoding the capsid proteins at the T-end and the replicases; at the T-end. In contrast, dicistroviruses have two nonoverlapping ORB. The 5'-proximal ORF encodes the replicases and the T-proximal ORF encodes the capsid proteins. Usually, positive-stranded viruses which have capsid protein genes in the 3' part of the genome produce subgenomic RNA for synthesis of the capsid proteins, because abundant quantities of the capsid proteins are required for the viral replication cycle. In dicistroviruses, translation of the capsid proteins is controlled by an additional IRES. This [RES is located in the intergenic region (IGR) between the replicase and capsid coding regions, and mediates the initiation of translation for the capsid proteins. The IGR-IRES has a multiple stem-loop structure containing three pseudoknots. We describe the characteristics of dicistroviruses, including the RNA elements and viral proteins. (c) 2008 Elsevier B.V. All rights reserved.