The Rho factor is a prokaryotic helicase protein that acts in bacteria to mediate the process of termination of transcription. In <em>Escherichia coli</em>, the Rho factor is a hexameric ring-shaped helicase and each subunit of this factor contains two domains involved in RNA binding and ATP hydrolysis. The Rho factor binds to the transcription terminator site on single-stranded RNA and then continues along the messenger RNA (mRNA) strand until it reaches the RNA polymerase, subsequently triggering its dissociation from the DNA and thus the termination of transcription.
