Poly (rC) binding protein 2 forms a ternary complex with the 5'-terminal sequences of poliovirus RNA and the viral 3CD proteinase.
Poly (rC) binding protein 2 forms a ternary complex with the 5'-terminal sequences of poliovirus RNA and the viral 3CD proteinase.
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发表时间：
1997-10
期刊：
影响因子：
4.5
通讯作者：
T. Parsley;Jonathan S. Towner;Lawrence B. Blyn;Ellie Ehrenfeld;B. Semler
中科院分区：
文献类型：
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作者：
T. Parsley;Jonathan S. Towner;Lawrence B. Blyn;Ellie Ehrenfeld;B. Semler
Poly（rC）binding protein 2（PCBP 2）与脊髓灰质炎病毒基因组RNA的5 '末端序列形成特异性核糖核蛋白（RNP）复合物，如通过电泳迁移率变动测定所确定。突变分析表明，结合需要在位置20-25处的野生型核苷酸序列。预测该序列定位于病毒RNA的5 '末端处的三叶草样二级结构元件内的特定茎环。向PCBP 2/RNA结合反应中加入纯化的脊髓灰质炎病毒3CD导致形成三元复合物，其电泳迁移率进一步减慢。这些性质与Andino等人（Andino R，Rieckhof GE，Achacoso PL，巴尔的摩D，1993，EMBO J 12：3587-3598）描述的RNP复合物中未鉴定的细胞蛋白质的性质一致。在脊髓灰质炎病毒的5'苜蓿叶样结构中含有突变的双顺反子RNA（其减弱PCBP 2结合）显示，体外脊髓灰质炎病毒5'非编码区指导的基因产物的RNA复制和翻译减少，表明PCBP 2与这些序列的相互作用通过促进病毒蛋白质合成和启动病毒RNA合成在病毒生命周期中发挥双重作用。
Poly(rC) binding protein 2 (PCBP2) forms a specific ribonucleoprotein (RNP) complex with the 5'-terminal sequences of poliovirus genomic RNA, as determined by electrophoretic mobility shift assay. Mutational analysis showed that binding requires the wild-type nucleotide sequence at positions 20-25. This sequence is predicted to localize to a specific stem-loop within a cloverleaf-like secondary structure element at the 5'-terminus of the viral RNA. Addition of purified poliovirus 3CD to the PCBP2/RNA binding reaction results in the formation of a ternary complex, whose electrophoretic mobility is further retarded. These properties are consistent with those described for the unidentified cellular protein in the RNP complex described by Andino et al. (Andino R, Rieckhof GE, Achacoso PL, Baltimore D, 1993, EMBO J 12:3587-3598). Dicistronic RNAs containing mutations in the 5' cloverleaf-like structure of poliovirus that abate PCBP2 binding show a decrease in RNA replication and translation of gene products directed by the poliovirus 5' noncoding region in vitro, suggesting that the interaction of PCBP2 with these sequences performs a dual role in the virus life cycle by facilitating both viral protein synthesis and initiation of viral RNA synthesis.