Iborra F J, Pombo A, McManus J, Jackson D A, Cook P R
CRC Nuclear Structure and Function Research Group, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, United Kingdom.
Exp Cell Res. 1996 Dec 15;229(2):167-73. doi: 10.1006/excr.1996.0355.
Current models for RNA synthesis involve an RNA polymerase that tracks along a static template. However, research on chromatin loops suggests that the template slides past a polymerase immobilized in a large transcription factory. The evidence for immobilized polymerases is reviewed, and a model for transcription by such fixed enzymes is presented. According to the model, gene activation would involve reducing gene-factory distance and increasing the affinity of a promoter for a factory. Locus controlling regions and enhancers would attach to a factory and increase the chances that a promoter could bind to a polymerase; after transcriptional termination, the gene would detach from the factory. As some RNA processing occurs cotranscriptionally, processing sites are also likely to be associated with the factory.
目前的RNA合成模型涉及一种沿着静态模板移动的RNA聚合酶。然而，对染色质环的研究表明，模板会滑过固定在大型转录工厂中的聚合酶。本文综述了固定化聚合酶的证据，并提出了由这种固定酶进行转录的模型。根据该模型，基因激活将涉及缩短基因与工厂的距离，并增加启动子对工厂的亲和力。基因座控制区和增强子将附着在工厂上，并增加启动子与聚合酶结合的机会；转录终止后，基因将从工厂上脱离。由于一些RNA加工是在转录过程中进行的，加工位点也可能与工厂相关联。
