If a mutation prevents the formation of the antiterminator 2+3 loop in the trp operon, what would be the effect?
A) transcription only when tryptophan is absent
B) transcription only when tryptophan is present
C) constitutive attenuation of transcription
D) constitutive transcription
E) no effect, as 2+3 loop has no function

Question

Quizplus · Accepted Answer

The 2+3 loop in the trp operon acts as an antiterminator, allowing transcription to continue. If this loop cannot form, the default terminator structure (3+4 loop) will form, leading to constitutive attenuation of transcription regardless of tryptophan levels.

If a Mutation Prevents the Formation of the Antiterminator 2+3