CHAPTER 7: Helicases and the Obstructive RNAP

RNA polymerase is so tightly associated with DNA during transcription elongation that interruption in its catalytic activity can result in a potent roadblock latched onto the DNA. If this roadblock is not removed it can cause conflicts with other RNA polymerases and also the DNA polymerases which replicate DNA. Specialized adenosine triphosphate-fueled molecular motors, such as helicases and translocases, are responsible for removing stalled RNA polymerase from DNA, with resulting roles in a wide range of processes including regulation of gene expression and transcription termination, DNA repair, and even adaptative mutagenesis.