In vivo restoration of biologically active 3' ends of virus-associated RNAs by nonhomologous RNA recombination and replacement of a terminal motif
In vivo restoration of biologically active 3' ends of virus-associated RNAs by nonhomologous RNA recombination and replacement of a terminal motif
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DOI：
10.1128/jvi.70.1.478-486.1996
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发表时间：
1996-01-01
影响因子：
5.4
通讯作者：
Simon, AE
中科院分区：
文献类型：
--
作者：
Carpenter, CD;Simon, AE
正链RNA病毒及其相关的亚病毒RNA的3‘端序列是体内和体外合成负链的重要顺式元件，所有与芜菁皱缩病毒(TCV)相关的RNA，包括基因组RNA(4,054个碱基)和卫星RNA(SAT-RNAs)，如sat-RNAD(194个碱基)，都是末端，即CCUGCCC基序。在研究体内产生的sat-RNAD和TCV之间的重组体在植物中被扩增的能力时，我们发现sat-RNAD，尽管在嵌合分子中截短了多达15个碱基，从嵌合转录本中释放出来，并扩增到高水平。“新的”sat-RNAD分子几乎都以基序(C-1-2)UG(C-1-3)(可能以1或2个胞嘧啶开始，以1、2或3个胞嘧啶结束)终止，这与天然的sat-RNAD‘末端相似或相同。新的sat-RNA D在末端基序的上游还含有1至22个碱基的异质序列，在某些情况下，显然来自TCV基因组RNA正链或负链的内部区域，由于TCV内的大多数内部基因组RNA序列与(C-1-2)UG(C-1-3)不相邻，因此至少需要两个步骤才能产生新的sat-RNA D‘末端：与TCV基因组RNA的非同源重组，然后添加或修饰末端以产生(C-1-2)UG(C-1-3)基序。
Sequences at the 3' ends of plus-strand RNA viruses and their associated subviral RNAs are important cis elements for the synthesis of minus strands in vivo and in vitro, All RNAs associated with turnip crinkle virus (TCV), including the genomic RNA (4,054 bases) and satellite RNAs (sat-RNAs) such as sat-RNA D (194 bases), terminate,vith the motif CCUGCCC, While investigating the ability of in vivo-generated recombinants between sat-RNA D and TCV to be amplified in planta, we discovered that sat-RNA D, although truncated by as many as 15 bases in the chimeric molecules, was released from the chimeric transcripts and amplified to high Levels. The ''new'' sat-RNA D molecules nearly all terminated with the motif (C-1-2)UG(C-1-3) (which may begin with 1 or 2 cytosines and end with 1, 2, or 3 cytosines), which was similar or identical to the natural sat-RNA D 3' end. The new sat-RNA D also contained between 1 and 22 bases of heterogeneous sequence upstream from the terminal motif, which, in some cases, was apparently derived from internal regions of either the plus or minus strand of the TCV genomic RNA, Since most of these internal genomic RNA sequences within TCV were not adjacent to (C-1-2)UG(C-1-3), at least two steps were required to produce new sat-RNA D 3' ends: nonhomologous recombination with the TCV genomic RNA followed by the addition or modification of the terminus to generate the (C-1-2)UG(C-1-3) motif.