摘要
The polycistronic RNAs from both bacteriophage R17 and Qβ are translated in a mammalian cell-free system of purified and partially purified components. The requirement of one of the partially purified initiation factors (IF-E3 from rabbit reticulocytes) for the phage RNA translation is strikingly different from that for rabbit globin messenger RNA translation. The phage RNA-directed products are characterized by acrylamide gel electrophoresis and compared with those synthesized in an Escherichia coli cell-free system. There is good agreement between the respective coat proteins and the presumptive synthetase proteins. R17 RNA directs the synthesis of two additional defined polypeptides. However, their possible relationship with the A-protein cistron has not yet been investigated. The RNA from the amB2 mutant of R17, which carries an amber triplet at position 6 in the coat protein cistron, directs the synthesis of the same polypeptides as the wild-type RNA with the exception of the coat protein which is completely abolished. This identifies the product made with wild-type RNA as coat protein and provides a direct in vitro assay for the suppression of nonsense mutations in eukaryotic cells.
摘要译文
来自噬菌体R17和Qβ的多顺反子RNA在纯化和部分纯化的组分的哺乳动物无细胞系统中翻译。用于噬菌体RNA翻译的部分纯化的起始因子之一（来自兔网织红细胞的IF-E 3）与兔子珠蛋白信使RNA翻译明显不同。噬菌体RNA指导的产物通过丙烯酰胺凝胶电泳表征，并与在大肠杆菌无细胞系统中合成的那些进行比较。各外壳蛋白和假定的合成酶蛋白之间存在良好的一致性。 R17 RNA指导两种另外确定的多肽的合成。然而，他们与A蛋白顺反子的可能关系尚未被研究过。来自R17的amB2突变体的RNA，其在外壳蛋白顺反子中的第6位带有琥珀三联体，除了完全消除的外壳蛋白外，它指导与野生型RNA相同的多肽的合成。这确定了用野生型RNA作为外壳蛋白制备的产物，并提供了用于抑制真核细胞中无义突变的直接体外测定。
Max H. Schreier Theophil Staehelin. Translation of bacteriophage R17 and Qβ RNA in a mammalian cell-free system[J]. Journal of Molecular Biology, 1973,75(3): 575-576, IN7-IN8, 577-578