You have purified a protein from a bacterium Y that causes cells in tissue culture to increase their cAMP levels. You subsequently cloned a fragment of DNA from bacterium Y that contained two ORFs,...

You have purified a protein from a bacterium Y that causes cells in tissue culture to increase their cAMP levels. You subsequently cloned a fragment of DNA from bacterium Y that contained two ORFs, one of which you identified as the gene encoding the protein you isolated, which you called yctA (for Y bacterium cytotoxin A). You then determined that expression of the YctA protein occurs only under iron-restrictive conditions (i.e., when iron is absent from the medium).

A. Describe how you would determine if the expression of YctA is regulated by iron at the transcriptional level.

B. Describe how you would determine whether the other ORF, which you have named yctR, encodes a possible transcriptional regulator.

C. If YctR is a transcriptional regulator, how could you determine if it is an activator or repressor protein?