An increase in tryptophan levels leads to attenuation of transcription in the trp operon. Which mechanism explains this feedback inhibition?

💡 Explanation

High levels of tryptophan cause the formation of a terminator hairpin loop in the trp operon mRNA, which halts transcription, because this conformational change provides a termination signal to RNA polymerase; therefore, transcription is attenuated, rather than enhanced or unaffected.

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