Nurturing Life Sciences
#Id: 789
#Id: 2429
#Unit 3. Fundamental Processes
Rho factor is an essential protein in E. coli that causes transcription termination.
#Id: 2430
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
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
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
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
The efficiency of a rut site increases with the length of the C-rich/G-poor region.