And finally, let's take a look at metalloprotiases. So, just like the name implies, this has to do with the fact that inside the active side of metalloproteases, we actually have a metal atom, and usually the metal atom is zinc. So what's the point of the metal atom? Well, for the same exact reason that we have this residue to basically transform the water into a better nuclear file here, we also have a metal atom to actually bind the water and transform it into a better nuclear file so that the water can basically hydrolyze that peptide bond. So if we examine the active side, as shown here, let's say we have the zinc metal atom that is actually bound to the active side of that enzyme. And so what it does is it interacts with the oxygen as a result of this being partially negative and this having a positive charge.