Hewlett M J, Florkiewicz R Z
Proc Natl Acad Sci U S A. 1980 Jan;77(1):303-7. doi: 10.1073/pnas.77.1.303.
Virion RNA (vRNA) from poliovirus type 1 (PV1), poliovirus type 2 (PV2), and coxsackie virus B1 (Cox B1) were treated with proteinase K to remove all but a small peptide of the covalently attached 5' genome-linked virion protein (VPg). The peptide on these RNA molecules was then treated with Bolton-Hunter 125I reagent, which iodinates primary amine groups, in order to obtain specific 5'-terminal radioactive labeling. Sequences of 125I-labeled vRNAs were determined by using a set of base-specific RNases and a partial alkaline hydrolysis "ladder." The first 20 positions of these RNAs show a remarkable conservation of sequence. The initial 10 nucleotides are identical in PV1, PV2, and Cox B1, with the sequence VPg-pU-U-A-A-A-A-C-A-G-C. The next 10 nucleotides show a one-base difference between PV1 and PV2 and 50% homology between PV1 and Cox B1. This conserved 5' region may provide a recognition site for interaction between the viral mRNA and the host translation system.
来自1型脊髓灰质炎病毒(PV1)、2型脊髓灰质炎病毒(PV2)和柯萨奇病毒B1(Cox B1)的病毒体RNA(vRNA)用蛋白酶K处理,以去除共价连接的5'基因组连接病毒体蛋白(VPg)除一小段肽以外的所有部分。然后用博尔顿-亨特125I试剂处理这些RNA分子上的肽,该试剂可碘化伯胺基团,以获得特异性的5'末端放射性标记。通过使用一组碱基特异性核糖核酸酶和部分碱性水解“梯状图谱”来确定125I标记的vRNA的序列。这些RNA的前20个位置显示出显著的序列保守性。最初的10个核苷酸在PV1、PV2和Cox B1中是相同的,序列为VPg-pU-U-A-A-A-A-C-A-G-C。接下来的10个核苷酸在PV1和PV2之间有一个碱基差异,在PV1和Cox B1之间有50%的同源性。这个保守的5'区域可能为病毒mRNA与宿主翻译系统之间的相互作用提供一个识别位点。