If the gene encoding the trp repressor is mutated such that it can no longer bind tryptophan but can still bind the operon, will transcription of the trp operon occur?
A) Yes, because the trp repressor can bind the trp operon and block transcription only when it is bound to tryptophan.
B) No, because this mutation does not affect the part of the repressor that can bind the operator.
C) No, because the trp operon is repressed only when tryptophan levels are high.
D) Yes, because the trp operon can allosterically regulate the enzymes needed to synthesize the amino acid tryptophan.
E) No, because the repressor will be continuously bound to the operator.

Question

Quizplus · Accepted Answer

The trp repressor can bind to the trp operon and block transcription only when it is in a complex with tryptophan. If the repressor can no longer bind tryptophan but can still bind the operon, it will not be able to block transcription, so the trp operon will be transcribed.

If the Gene Encoding the Trp Repressor Is Mutated Such