And the reason we call it the P loop is because this polypeptide section is the section that contains the amino acids that are responsible for actually binding to and interacting with the ATP molecule. And more specifically, it will interact with the negative charges on this triphosphate group of that ATP molecule. And if we study the sequence of nucleotides among the different types of NMP kinases on that p loop, this is what we're going to see. So it's relatively conserved. So we have a glycine followed by four x's, where the x basically describes some type of arbitrary amino acid. And then we have glycine and lycine.