Frey T K, Marr L D, Sanchez A, Simmons R B
Department of Biology, Georgia State University, Atlanta 30303.
Virology. 1989 Jan;168(1):191-4. doi: 10.1016/0042-6822(89)90422-4.
The 5' end of the subgenomic RNA of rubella virus was determined by primer extension. The Maxam-Gilbert sequence ladder of the primer extension product contained a determinable sequence which was colinear with the complement of the sequence of the genomic RNA through nucleotide 3325 from the 3' end of the genomic RNA and a pair of bands in every lane above the determinable sequence. These results indicated that synthesis of the subgenomic RNA is initiated internally on the minus-polarity genome-length RNA template and that the length of subgenomic RNA is 3327 nucleotides excluding the poly(A) tail. There are thus 77 nucleotides between the 5' end of the subgenomic RNA and the first AUG, which is the initiation codon for the structural protein open reading frame. The initiation site of rubella virus subgenomic RNA synthesis is 20 nucleotides downstream from a block of 28 nucleotides which shares homology with the nucleotide sequence which is conserved at the subgenomic RNA initiation site in the Alphaviruses, the other genus of Togaviruses.
风疹病毒亚基因组RNA的5'端通过引物延伸法测定。引物延伸产物的Maxam-Gilbert序列梯包含一个可确定的序列，该序列与基因组RNA从3'端起至核苷酸3325的序列互补呈共线性，并且在可确定序列上方的每条泳道中有一对条带。这些结果表明，亚基因组RNA的合成在负链基因组长度RNA模板上从内部起始，并且亚基因组RNA的长度为3327个核苷酸（不包括聚腺苷酸尾）。因此，亚基因组RNA的5'端与第一个AUG（即结构蛋白开放阅读框的起始密码子）之间有77个核苷酸。风疹病毒亚基因组RNA合成的起始位点位于一段28个核苷酸区域下游20个核苷酸处，该28个核苷酸区域与甲病毒属（披膜病毒科的另一属）亚基因组RNA起始位点处保守的核苷酸序列具有同源性。
