But what exactly is the structure inside the cell that allows us to break down these proteins? Well, it's a structure known as the proteasome. And the proteasome is an ATP driven multisubune complex that actually consists of two Subun units or two units. So one of these units we call the other unit we call the actually, as we see in this particular diagram we have two nineteen S units that flank the 20s subunit on both sides. Now, the, as we'll see in just a moment are actually regulatory units and it's the that basically catalyzes the breakdown of the protein. Now, if we zoom in on this twenty S unit we basically find this structure here.