If tryptophan were to serve to decrease gene expression, how could it interact with a repressor, and an activator, respectively, to mediate this decrease in trp operon expression?

Question

In this scenario, which of these two transcription factors would be inherently capable of binding the DNA operator, and which needs help from tryptophan?

Answer 1

In order for tryptophan to decrease gene expression it would have to activate the repressor. The trp operon will repress (stop the gene expression) the activator which would not allow for gene expression to occur. The repressor will bind to the operator with the help of tryptophan.