Liu B, Wong M L, Alberts B
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Proc Natl Acad Sci U S A. 1994 Oct 25;91(22):10660-4. doi: 10.1073/pnas.91.22.10660.
We have demonstrated elsewhere that a precisely placed, stalled Escherichia coli RNA polymerase ternary transcription complex (polymerase-RNA-DNA) stays on the DNA template after passage of a DNA replication fork. Moreover, the bypassed complex remains competent to resume elongation of its bound RNA chain. But the simplicity of our experimental system left several important questions unresolved: in particular, might the observation be relevant only to the particular ternary complex that we studied, and can the finding be generalized to a transcribing instead of a stalled RNA polymerase? To address these issues, we have created three additional ternary transcription complexes and examined their fates after passage of a replication fork. In addition, we have examined the fate of moving RNA polymerase molecules during DNA replication. The results suggest that our previous finding applies to all transcription intermediates of the E. coli RNA polymerase.
我们已在其他地方证明，一个精确定位的、停滞的大肠杆菌RNA聚合酶三元转录复合物（聚合酶-RNA-DNA）在DNA复制叉通过后仍保留在DNA模板上。此外，被绕过的复合物仍有能力恢复其结合的RNA链的延伸。但我们实验系统的简单性留下了几个重要问题未解决：特别是，该观察结果是否仅与我们研究的特定三元复合物相关，以及该发现能否推广到正在转录而非停滞的RNA聚合酶？为了解决这些问题，我们创建了另外三种三元转录复合物，并检查了复制叉通过后它们的命运。此外，我们还研究了DNA复制过程中移动的RNA聚合酶分子的命运。结果表明，我们之前的发现适用于大肠杆菌RNA聚合酶的所有转录中间体。
