申論題

35. You have just discovered a new putative repressor in a strain of (E) coli that was sent to you by a colleague. One of the best ways to test for the specificity of this repressor for an operator sequence is to (A) replace the putative DNA-binding site with the binding site from another repressor. (B) change some of the amino acids in the binding site by site-directed mutagenesis. (C) insert an additional segment of amino acids next to the DNA binding site. (D) replace the putative DNA-binding site with the binding site from another repressor and change some of the amino acids in the binding site by site-directed mutagenesis.