Hercyk N, Horikami S M, Moyer S A
Department of Microbiology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232.
Virology. 1988 Mar;163(1):222-5. doi: 10.1016/0042-6822(88)90253-x.
We have previously shown that the vesicular stomatitis virus (VSV) host range mutant, hr 1, is completely defective for the mRNA methyltransferase activities, but can synthesize full-length, unmethylated mRNAs in vitro [S. M. Horikami and S. A. Moyer (1982). Proc. Natl. Acad. Sci. USA 79, 7694-7698] and in vivo [S. M. Horikami, F. De Ferra, and S. A. Moyer (1984). Virology 138, 1-15]. Here we have used the hr 1 mutant to identify the viral protein which possesses the methyltransferase activities. The wild-type VSV L and NS proteins, subunits of the viral RNA polymerase, were separately purified and added to high salt dissociated mutant hr 1 nucleocapsids for in vitro transcription reactions. The results show that the purified wild-type L protein, but not the NS protein, restores methylation and thus possesses the viral mRNA methyltransferase activities.
我们之前已经表明，水泡性口炎病毒（VSV）宿主范围突变体hr 1在mRNA甲基转移酶活性方面完全缺陷，但能够在体外[S. M. 堀上和S. A. 莫耶（1982年）。美国国家科学院院刊79，7694 - 7698]和体内[S. M. 堀上、F. 德费拉和S. A. 莫耶（1984年）。病毒学138，1 - 15]合成全长、未甲基化的mRNA。在此，我们利用hr 1突变体来鉴定具有甲基转移酶活性的病毒蛋白。野生型VSV L蛋白和NS蛋白，即病毒RNA聚合酶的亚基，被分别纯化，并添加到高盐解离的突变体hr 1核衣壳中用于体外转录反应。结果表明，纯化的野生型L蛋白而非NS蛋白可恢复甲基化，因此具有病毒mRNA甲基转移酶活性。
