. "Authored: Gopinathrao, G, 2004-06-23 11:10:00"^^ . "RNA Pol II arrest is believed to be a result of irreversible backsliding of the enzyme by ~7-14 nucleotides. It is suggested that, arrest leads to extrusion of displaced transcripts 3'-end through the small pore near the Mg2+ ion. Pol II arrest may lead to abortive termination of elongation due to irreversible trapping of the 3'-end of the displaced transcript in the pore (reviewed by Shilatifard et al., 2003)."^^ . . . . . . "7-14 nt. Backtracking of Pol II complex on the template leading to elongation arrest"^^ . . .