Uses attenuation as a mechanism to control expression of its genes.

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The trp operon uses attenuation to control expression of its genes. Attenuation is a mechanism by which gene expression is controlled by the premature termination of transcription in response to a particular regulatory molecule. It occurs in the trp operon when the presence of tryptophan activates the binding of a repressor protein to the operator region, preventing transcription of the full operon. However, the trp operon also contains a region called the leader sequence that can form different stem-loop structures, depending on whether or not tryptophan is present. The formation of the stem-loop structures in the leader sequence can either favor or interfere with the formation of a transcription termination hairpin in the downstream mRNA. This is called attenuation, and it allows the cell to fine-tune the expression of the trp operon in response to the availability of tryptophan.

Uses Attenuation as a Mechanism to Control Expression of Its