Which of the following evidence best supports a claim that tryptophan functions as a corepressor? A. Normal expression of trpR c
auses the trp operon to be transcribed regardless of tryptophan levels. B. When the operator sequence is mutated, the trp operon is not transcribed. C. The trpR gene codes for a repressor protein that has a DNA binding domain. D. When trpR is mutated, the trp operon is transcribed regardless of tryptophan levels.
