Pettersson R F, Söderlund H, Kääriäinen L
Eur J Biochem. 1980 Apr;105(3):435-43. doi: 10.1111/j.1432-1033.1980.tb04518.x.
To study the mechanism of the synthesis of Semliki Forest virus (SFV) 26-S RNA, we have isolated the 5'-terminal 'cap'-containing RNase-T1-resistant oligonucleotide (T1 cap) from the genomic 42-S RNA and from the subgenomic 26-S RNA and determined their nucleotide sequences. The T1 caps were purified from 32P-labelled RNAs on two successive two-dimensional fractionation systems: (a) electrophoresis on cellulose acetate paper followed by homochromatography and (b) two-dimensional polyacrylamide gel electrophoresis. The T1 caps derived from the two RNAs had different mobilities in both systems. Their nucleotide sequence was found to be: m7G(5')ppp-(5')ApUpGp- for the 42-S RNA and m7G(5')ppp(5')ApUpUpGp- for the 26-S RNA, respectively. Thus, it appears that the 26-S RNA is not formed by initiation of the RNA polymerase at the 3' end of the negative-strand template followed by 'cleavage and splicing' or as the result of a 'polymerase jump'. Our results, instead, favour the model of internal initiation of the polymerase on the 42-S negative-strand RNA template.
为了研究塞姆利基森林病毒（SFV）26 - S RNA的合成机制，我们从基因组42 - S RNA和亚基因组26 - S RNA中分离出了5'末端含“帽”的核糖核酸酶T1抗性寡核苷酸（T1帽），并确定了它们的核苷酸序列。T1帽是在两个连续的二维分级分离系统上从32P标记的RNA中纯化出来的：（a）在醋酸纤维素纸上进行电泳，然后进行同系层析；（b）二维聚丙烯酰胺凝胶电泳。在这两个系统中，源自两种RNA的T1帽具有不同的迁移率。发现它们的核苷酸序列分别为：42 - S RNA的是m7G(5')ppp-(5')ApUpGp-，26 - S RNA的是m7G(5')ppp(5')ApUpUpGp-。因此，26 - S RNA似乎不是由RNA聚合酶在负链模板的3'末端起始，随后进行“切割和剪接”形成的，也不是“聚合酶跳跃”的结果。相反，我们的结果支持聚合酶在42 - S负链RNA模板上进行内部起始的模型。
