So it's exactly what we said before. It's the sequence of amino acids that is found around the side that residue that is about to be phosphorylated that determines the ability of that protein kinase Apka to actually bind onto that substrate molecule. Now, what is the sequence? Well, the sequence known as the consensus sequence is shown on the board. So basically, if the substrate molecule contains arginine, arginine, x, serene, three or three ending and y, where X is basically any small amino acid for instance glycine and y is basically any large hydrophobic amino acid. This is basically where that protein kinase will buy to and it will phosphorylate this target side, the serine or thyrionine.