Question

In the mechanism of transcription attenuation of the trp operon, the leader peptide mechanism is analogous to a repressor protein.

a. true
b. false

Answer 1

The leader peptide mechanism in the transcription attenuation of the trp operon is analogous to an activator protein, not a repressor protein.

Step-by-step explanation:

The statement is false. The leader peptide mechanism in the transcription attenuation of the trp operon is analogous to an activator protein, not a repressor protein. In the trp operon, the leader peptide sequence, known as trpL, contains regions that can form stem-loop structures.

When tryptophan levels are low, translation of the leader peptide stalls in region 1, allowing regions 2 and 3 to form an antiterminator loop. This prevents the formation of the terminator stem-loop, and RNA polymerase can then transcribe the structural genes of the trp operon.

Therefore, the leader peptide mechanism in the transcription attenuation of the trp operon is analogous to an activator protein, not a repressor protein.