Facilitated recycling pathway for RNA polymerase III
Facilitated recycling pathway for RNA polymerase III
复制标题
DOI：
10.1016/s0092-8674(00)80979-4
复制
发表时间：
1996-01-26
期刊：
影响因子：
64.5
通讯作者：
Sentenac, A
中科院分区：
文献类型：
--
作者：
Dieci, G;Sentenac, A
我们表明，酵母RNA poI III的体外转录效率高，主要是由于快速回收。动力学分析表明，RNA聚合酶在预组装的tDNA上循环。TFIIIC。TFIIIB复合物比初始转录周期快得多。高效率的RNA poI III再循环在高UTP浓度下是有利的，并且需要在天然终止信号处终止。径流转录不允许有效的再循环。与初次启动循环相比，重新启动过程显示出对肝素的抗性增加，就好像终止后RNA聚合酶未释放一样。事实上，模板竞争试验表明，RNA poI III致力于在同一基因上重新启动。提出了一种模型，其中聚合酶分子直接从终止位点转移到启动子。
We show that the high in vitro transcription efficiency of yeast RNA poI III is mainly due to rapid recycling. Kinetic analysis shows that RNA polymerase recycling on preassembled tDNA . TFIIIC . TFIIIB complexes is much faster than the initial transcription cycle. High efficiency of RNA poI III recycling is favored at high UTP concentrations and requires termination at the natural termination signal. Runoff transcription does not allow efficient recycling. The reinitiation process shows increased resistance to heparin as compared with the primary initiation cycle, as if RNA polymerase was not released after termination. Indeed, template competition assays show that RNA poI III is committed to reinitiate on the same gene. A model is proposed where the polymerase molecule is directly transferred from the termination site to the promoter.