Rut sites in bacterial transcription are bound by which protein?

Rho helicase is the correct protein that binds to rut sites during bacterial transcription. Rut sites, short for "Rho utilization sites," are specific sequences in bacterial mRNA that serve as recognition points for the Rho protein. This protein plays a critical role in the process of transcription termination.

When RNA polymerase transcribes a gene, Rho helicase can bind to the newly synthesized RNA at these rut sites. This action occurs especially when RNA polymerase encounters a pause or a region of transcription that lacks a stable stem-loop structure. Once Rho is bound to the rut site and the polymerase is paused, Rho utilizes its helicase activity to translocate along the RNA, eventually leading to the termination of transcription by unwinding the RNA-DNA hybrid within the transcription bubble.

This mechanism highlights the significance of Rho as a key player in the regulation of transcription termination in prokaryotes. Other proteins mentioned, such as the Lambda repressor, play roles in different regulatory pathways, and elongation factors assist in the elongation phase of transcription but are not directly involved with rut sites. TBP, or TATA-binding protein, is primarily associated with the initiation of transcription in eukaryotes rather than bacterial systems