Formosa T, Alberts B M
Cell. 1986 Dec 5;47(5):793-806. doi: 10.1016/0092-8674(86)90522-2.
To simulate a reaction that occurs in T4-infected cells, we have developed an in vitro DNA synthesis system that requires seven highly purified proteins encoded by this bacteriophage: the DNA polymerase "holoenzyme" (four proteins), gene 32 protein, dda DNA helicase, and uvsX protein - an enzyme that catalyzes homologous DNA pairing and is functionally homologous to the recA protein. In the reaction observed, the 3'OH end of one single-stranded DNA molecule primes DNA synthesis using a double-stranded DNA molecule of homologous sequence as the template. The uvsX protein continuously removes the new DNA chain from its template, so that DNA is synthesized by a conservative mechanism. This type of reaction, which requires the cooperation of recombination and replication enzymes, seems likely to be a general feature of DNA metabolism.
为了模拟在T4感染细胞中发生的反应，我们开发了一种体外DNA合成系统，该系统需要由这种噬菌体编码的七种高度纯化的蛋白质：DNA聚合酶“全酶”（四种蛋白质）、基因32蛋白、dda DNA解旋酶和uvsX蛋白——一种催化同源DNA配对且在功能上与recA蛋白同源的酶。在观察到的反应中，一个单链DNA分子的3'OH末端以同源序列的双链DNA分子为模板引发DNA合成。uvsX蛋白持续将新的DNA链从其模板上移除，从而使DNA通过保守机制合成。这种需要重组和复制酶协同作用的反应类型，似乎很可能是DNA代谢的一个普遍特征。
