Active genes are often found at the borders of chromosome territories, and active genes from several chromosomes may cluster in inter-chromosomal territories that are enriched in transcription machinery.

TLS Online TPP Program

#Id: 2429

#Unit 3. Fundamental Processes

Rho factor is an essential protein in E. coli that causes transcription termination.

TLS Online TPP Program

#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.

TLS Online TPP Program

#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).

TLS Online TPP Program

#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.

TLS Online TPP Program

#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.

TLS Online TPP Program

#Id: 2434

#Unit 3. Fundamental Processes

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