G1/S phase CDKs phosphorylate Cdh1 at the 

G1-S phase transition

#Id: 2430

#Unit 3. Fundamental Processes

The rho concentration may be as high as,10% the concentration of RNA polymerase. Rho-independent termination accounts for almost half of E. coli terminators.

#Id: 2431

#Unit 3. Fundamental Processes

Rho binds to a sequence within the transcript upstream of the site of termination. This sequence is called a rut site (an acronym for rho utilization).

#Id: 2432

#Unit 3. Fundamental Processes

When the RNA polymerase reaches the termination site, rho first freezes the structure of the polymerase and then invades the exit channel to destabilize the enzyme, causing it to release the RNA.

#Id: 2433

#Unit 3. Fundamental Processes

Pausing by the polymerase at the site of termination allows time for rho factor to translocate to the hybrid stretch and is an important feature of termination.

#Id: 2434

#Unit 3. Fundamental Processes

The efficiency of a rut site increases with the length of the C-rich/G-poor region.

#Id: 2435

#Unit 3. Fundamental Processes

Rho is a member of the family of hexameric ATP-dependent helicases. Each subunit has an RNA-binding domain and an ATP hydrolysis domain.