So the next question is what exactly did scientists see when they mixed the poly with this enzyme? Well, what they saw was where that poly actually bound to was at the interface between any pair of these catalytic chains within that primer. So the poly inhibitor binds onto a region located on the boundaries of each pair of catalytic subunits in any one of those catalytic trimmers. And because we have three of these boundaries between the pairs in any given trimer, we see that we have three of these active sites in any trimer. And because we have two triumphs, that implies we must have six active sites. So we see that the quotinary structure of the ATCAs actually consists of six individual active sites.