Rho is a primary protein in the process of factor-dependant termination of transcription within bacteria. It is a hexeramic helicase, made up of identical subunits, that hydrolyzes ATP in the presence of single-stranded RNA. Rho's structure allows it to pull the nascent RNA through its centre when it encounters specific, Cytosine rich sequences that activate it called a Rho Utilisation site (RUT). This activation causes Rho to continue pulling RNA whilst pursuing the RNA Polymerase further upstream. Upon reaching the polymerase at the transcription bubble, Rho employs its helicase activity and unwinds the RNA-DNA hybrid helix. The RNA dissociates.