Reeve A E, Shatkin A J, Huang R C
J Biol Chem. 1982 Jun 25;257(12):7018-22.
RNA synthesized by reovirus cores was not capped or methylated when GTP was replaced by guanosine 5'-O-(3-thiotriphosphate) [gamma-S]GTP as a reaction substrate. Full length transcripts were synthesized in the presence of [gamma-S]GTP which indicated that capping could be dissociated from the process of transcription. Exogenous [gamma-S]GTP was not cleaved by the virion-associated phosphohydrolase and the majority of transcripts contained triphosphorylated 5'-termini. [gamma-S]GTP did, however, act as a donor for the capping of RNA chains initiated with GTP. Chromatography on mercury-agarose of products initiated with [gamma-S]GTP resulted in the binding of only the small (14 S) size class of RNA, although transcripts not bound to the affinity column were also thiophosphorylated.
当用鸟苷 5'-O-(3-硫代三磷酸)[γ-S]GTP 作为反应底物取代 GTP 时，呼肠孤病毒核心合成的 RNA 没有被加帽或甲基化。在[γ-S]GTP 存在的情况下合成了全长转录本，这表明加帽可以与转录过程分离。外源性[γ-S]GTP 未被病毒体相关的磷酸水解酶切割，并且大多数转录本含有三磷酸化的 5'-末端。然而，[γ-S]GTP 确实作为用 GTP 起始的 RNA 链加帽的供体。用[γ-S]GTP 起始的产物在汞琼脂糖上进行色谱分析，结果只有小尺寸（14 S）类别的 RNA 结合，尽管未结合到亲和柱上的转录本也被硫代磷酸化。
