And that's what happens when going from the E one stage to the E one calcium two stage. So now we have the two calcium ions inside the transmembrane domain. And now the ATP can actually go in and bind and interact with this green domain, the end domain. So remember, the end domain binds that ATP nucleotide to this section. And so now we go from this stage to the e one calcium to ATP stage. And as soon as the ATP binds onto this green section, it creates a localized conformational change in the green structure, the blue structure, and this purple structure.