Practice question

Rho protein functions as homohexameric motor translocating along nascent RNA toward polymerase, coupling ATP hydrolysis to RNA displacement. Structural analysis reveals each subunit contains N-terminal oligonucleotide-binding domain forming primary C-rich rut binding site and C-terminal RecA-like ATPase domain providing RNA-dependent ATPase and 5' to 3' helicase activities. Mechanism resembles ring helicase threading RNA through central pore. Rather than simple endonuclease or ligase, Rho acts mechanical translocase unwinding RNA-DNA hybrid within elongation complex. Inhibitor bicyclomycin targets ATPase pocket, validating RNA-dependent ATPase helicase classification essential for factor-dependent termination pathway.