Dreher T W, Goodwin J B
Department of Microbiology and Center for Gene Research and Biotechnology, Oregon State University, Corvallis, OR 97331-3804, USA.
Nucleic Acids Res. 1998 Oct 1;26(19):4356-64. doi: 10.1093/nar/26.19.4356.
Three tRNA-associated properties of a representative set of tymoviral RNAs have been quantitatively assessed using higher plant (wheat germ) proteins: aminoacylation, EF-1alphaGTP binding, and 3'-adenylation of 3'-CC forms of the RNAs by CTP, ATP:tRNA nucleotidyltransferase. The RNAs fall into three classes differing in the extent of tRNA mimicry. Turnip yellow mosaic (TYMV) and kennedya yellow mosaic virus RNAs had activities in all three properties similar to those of a higher plant tRNAValtranscript, and thus are remarkable tRNA mimics. Although the isolated approximately 83 nt long tRNA-like structures showed high activity in these assays, in the case of TYMV, the 6318 nt long TYMV RNA was an even better substrate for valylation. Eggplant mosaic virus RNA, which has a differently constructed acceptor stem pseudoknot, differed from the above tymoviral RNAs in binding more weakly to EF-1alphaGTP. Erysimum latent virus RNA, which lacks an identifiable anticodon domain, could not be valylated and had very low 3'-adenylation activity. The range of tRNA mimicry within the tymovirus genus thus ranges from extremely highly developed to minimal. The implications on the role of the tRNA mimicry in viral biology are discussed.
已使用高等植物（小麦胚芽）蛋白对一组具有代表性的芜菁黄花叶病毒属RNA的三种与tRNA相关的特性进行了定量评估：氨酰化、EF-1αGTP结合以及通过CTP、ATP:tRNA核苷酸转移酶对RNA的3'-CC形式进行3'-腺苷化。这些RNA可分为三类，它们在模拟tRNA的程度上有所不同。芜菁黄花叶病毒（TYMV）和肯尼迪氏黄花叶病毒的RNA在所有这三种特性方面的活性与高等植物tRNAVal转录本的活性相似，因此是显著的tRNA模拟物。尽管分离出的约83个核苷酸长的类tRNA结构在这些测定中显示出高活性，但就TYMV而言，6318个核苷酸长的TYMV RNA是更好的缬氨酰化底物。茄子花叶病毒RNA具有不同构建的受体茎假结，与上述芜菁黄花叶病毒属RNA不同，它与EF-1αGTP的结合较弱。缺乏可识别的反密码子结构域的糖芥潜隐病毒RNA不能被氨酰化，并且3'-腺苷化活性非常低。因此，芜菁黄花叶病毒属内的tRNA模拟范围从极其高度发达到最低限度。本文讨论了tRNA模拟在病毒生物学中的作用。
