Partial purification and characterization of Cucumber necrosis virus and Tomato bushy stunt virus RNA-dependent RNA polymerases:: Similarities and differences in template usage between tombusvirus and carmovirus RNA-dependent RNA polymerases
Partial purification and characterization of Cucumber necrosis virus and Tomato bushy stunt virus RNA-dependent RNA polymerases:: Similarities and differences in template usage between tombusvirus and carmovirus RNA-dependent RNA polymerases
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DOI：
10.1006/viro.2000.0577
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发表时间：
2000-10-25
期刊：
影响因子：
3.7
通讯作者：
Pogany, J
中科院分区：
文献类型：
--
作者：
Nagy, PD;Pogany, J
番茄丛矮病毒（Tomato bushy stunt virus，TBSV）和黄瓜坏死病毒（Cucumber necrosis virus，CNV）的RNA依赖性RNA聚合酶（RNA dependent RNA polymerases，RdRp）已从受侵染的本氏烟草（Nicotiana benthamiana）中部分纯化。所获得的RdRp复合物能够从头启动互补RNA的合成，使用正链或负链模板来自于番茄丛矮病毒缺陷型干扰（DI）RNA。除了模板大小的产品，短于全长的产品也有效地产生，显然是因为内部启动的RNA合成的番茄丛矮病毒RdRp。这种性质对于在番茄丛矮病毒感染中观察到的pi RNA的形成可能是重要的。番茄丛矮病毒RdRp还能够使用来源于与芜菁皱缩病毒（TCV）相关的卫星RNA的异源RNA作为模板。由Tombusvirus RdRp产生的全长互补RNA表明它可以正确有效地识别异源TCV特异性启动子。在前述测定中3 '末端延伸产物的产生减少表明先前表征的存在于sat-RNA C中的复制增强子（Nagy等人，18，5653-5665）并不刺激番茄丛矮病毒RdRp活性。总之，这些结果表明，番茄丛矮病毒和香石竹病毒RdRp的模板使用是相似的。但不完全相同。(C)北京大学出版社.
Tombusviruses are small, plus-sense, single-stranded RNA viruses of plants, RNA-dependent RNA polymerases (RdRp) of two tombusviruses, Tomato bushy stunt virus (TBSV) and Cucumber necrosis virus (CNV), have been partially purified from infected Nicotiana benthamiana plants. The obtained RdRp complexes are capable of de novo initiation of complementary RNA synthesis using either plus- or minus-strand templates derived from tombusvirus defective interfering (DI) RNAs. In addition to template-sized products, shorter than full-length products were also generated efficiently apparently because of internal initiation of RNA synthesis by the tombusvirus RdRp. This property could be important for the formation of pi RNAs that are observed in tombusvirus infections. The tombusvirus RdRp is also able to use heterologous RNAs derived from satellite RNAs associated with Turnip crinkle virus (TCV) as templates. Generation of full-length, complementary RNA by the tombusvirus RdRp suggests that it can correctly and efficiently recognize the heterologous TCV-specific promoters. Reduced generation of a 3'-terminal extension product in the preceding assay suggests that the previously characterized replication enhancer present in sat-RNA C (Nagy et ai., 1999, EMBO J. 18, 5653-5665) does not stimulate tombusvirus RdRp activity Taken together, these results suggest that template usage by the tombusvirus and carmovirus RdRps are similar. but not identical. (C) 2000 Academic Press.