title: The topology of transcription by immobilized polymerases.
abstract: 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.
authors.affiliation: CRC Nuclear Structure and Function Research Group, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, United Kingdom. Peter.Cook@Path.OX.AC.UK
authors.forename: F J
authors.initials: FJ
authors.lastname: Iborra
authors.forename: A
authors.initials: A
authors.lastname: Pombo
authors.forename: J
authors.initials: J
authors.lastname: McManus
authors.forename: D A
authors.initials: DA
authors.lastname: Jackson
authors.forename: P R
authors.initials: PR
authors.lastname: Cook
mesh_terms: D004247:DNA / Q000235:genetics / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004800:Enzymes, Immobilized; D005786:Gene Expression Regulation; D008957:Models, Genetic; D011401:Promoter Regions, Genetic; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D004800:Enzymes, Immobilized; D012313:RNA; D004247:DNA; D012321:DNA-Directed RNA Polymerases