A topological model for chromatin transcription and a role for nucleosome linkers.
There is a good deal of evidence that transcribing RNA polymerase may translocate across nucleosomes without their displacement and (or) rearrangement. A topological model for RNA chain elongation on a nucleosome is considered here. A new mechanism of RNA polymerase translocation is suggested in order to avoid the steric hindrances inherent in the model. It is shown that a transcribed nucleoprotein fiber should be interrupted by protein-free DNA stretches (nucleosome linkers) to allow release of nascent RNA. Possible verifications and consequences of the model are discussed.
D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D008954:Models, Biological; D009707:Nucleosomes / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D014158:Transcription, Genetic
D002843:Chromatin; D009707:Nucleosomes; D012313:RNA; D004247:DNA; D012321:DNA-Directed RNA Polymerases