Facilitates transcription termination by a mechanism that involves Rho binding to the nascent RNA, activation of Rho's RNA-dependent ATPase activity, and release of the mRNA from the DNA template. RNA-dependent NTPase which utilizes all four ribonucleoside triphosphates as substrates. ATPase activity is inhibited by bicyclomycin and dihydrobicyclomycin. Homohexamer. The homohexamer assembles into an open ring structure. Each subunit has two RNA-binding sites, one at the surface of the hexameric ring, and one at the center of the open ring structure, where RNA helicase activity is thought to take place. Belongs to the Rho family.