And actually the subunit contains three types of domains or actually two types of domains but overall three domains. So we have one domain here, then we have an intermediate domain and another domain here. And these domains are essentially identical but they're different to this middle domain. And we see that we have active sites found right over here, right next to this domain and here right next to this domain. And interestingly, what happens is these two molecules don't actually bind to the active side together. It's the oxalo acetate that binds into the active side of that enzyme.