Blumenthal T, Landers T A, Weber K
Proc Natl Acad Sci U S A. 1972 May;69(5):1313-7. doi: 10.1073/pnas.69.5.1313.
The enzyme, Qbeta replicase, responsible for the replication of the RNA of Escherichia coli pahge Qbeta, is composed of four nonidentical subunits, three of which, I, III, and IV, are coded for by the bacterial genome, while subunit II is phage-specific. SUBUNIT IV IS SHOWN TO BE IDENTICAL TO THE PROTEIN SYNTHESIS ELONGATION FACTOR EF TS BY THE FOLLOWING CRITERIA: coelectrophoresis on polyacrylamide gels in sodium dodecyl sulfate and in urea buffers, identity of the first seven amino acids at the amino-terminus, precipitation of sub-unit IV by anti-EF T-factor serum, and stimulation of EF Tu-GDP exchange by subunit IV. Subunit III is shown to be identical to the protein synthesis elongation factor EF Tu by the following criteria: coelectrophoresis on sodium dodecyl sulfate gels, precipitation of EF Tu by anti-Qbeta replicase serum, binding of guanine nucleotides, and binding of phenylalanyl-tRNA. In addition, Qbeta replicase activity can be reconstituted from subunits I and II with EF Tu and EF Ts.
负责大肠杆菌噬菌体Qβ RNA复制的酶——Qβ复制酶，由四个不同的亚基组成，其中三个亚基（I、III和IV）由细菌基因组编码，而亚基II是噬菌体特异性的。通过以下标准表明亚基IV与蛋白质合成延伸因子EF Ts相同：在十二烷基硫酸钠和尿素缓冲液中于聚丙烯酰胺凝胶上进行共电泳、氨基末端前七个氨基酸相同、抗EF T因子血清使亚基IV沉淀，以及亚基IV刺激EF Tu - GDP交换。通过以下标准表明亚基III与蛋白质合成延伸因子EF Tu相同：在十二烷基硫酸钠凝胶上进行共电泳、抗Qβ复制酶血清使EF Tu沉淀、鸟嘌呤核苷酸结合以及苯丙氨酰 - tRNA结合。此外，Qβ复制酶活性可以由亚基I和II与EF Tu和EF Ts重组而成。
