Explain how the fine attenuated control of the trp operon wo

Explain how the fine (attenuated) control of the trp operon works. How does the cell turn on the trp operon when trp levels are low? How does the cell turn off the trp operon when trp levels are high?

Solution

The attenuation in trp operon is the second mechanism of negative feedback. The attenuation of the operon depends on the levels of the trp in the system. The attenuation decreased the gene expression by altering the process of transcription that\'s already going. The process of attenuation is capable of causing a repression in the gene expression by a factor to 10 in addition to 70 fold by the TrpR repressor. In the process of attenuation, the ribosome that is translating the protein is stalled and is determined whether the termination hairpin will be formed or not.

The trp operon gets activated when the levels of tryptophan are low. This is done by the dissociation of the repressor protein to the operator sequence which allows the RNA polymerase to transcribe the trp genes.

The trp operon gets repressed when the levels of the tryptophan are high in the system. The repressor protein binds to the operator sequence mediated by a corepressor which blocks the RNA polymerase from transcribing the trp genes.