Now, of course, we can also change the arginine to lysine and that will also allow the protein kinase to bind onto this sequence. But if these are changed to Lysine, the Affidavit will not be as good as in the case where these two are arginine molecule arginine amino acids. So we see that the consensus sequence that is recognized by protein kinase A is shown to the left. And this means that enzymes, substrate molecules that contain serene or threeamine surrounded by this specific sequence will be recognized by the protein kinase A and the protein kinase A will bind onto this section and will phosphorylate this target side. And by phosphorylate it can basically change the activity and the functionality of that target substrate molecule. Now, earlier we said that it's a cyclic ANP molecule that actually binds and activates protein kinase A.