Termination factor

Termination is part of the process of transcribing RNA. In eukaryotes, a termination factor is required to release the newly made (nascent) RNA from the transcription complex. Prokaryote mRNAs often do not require a termination factor: an inverted repeat followed by a string of Us (uracils) in the mRNA template strand forms a stem-loop structure which destabilizes binding by the RNA polymerase and causes Rho-independent transcription termination.