Now on top of that the A subunit actually also holds this. The asymmet also actually connects this C structure to this structure that is part of the F one unit. So as shown in the following diagram we have a single A sub unit that is attached onto this arm which consists of two B change and that in turn is attached onto that delta subunit. And together this entire structure connects the F not to the F one section. So a single A subunit that binds to the outside of the C ring structure and the A subunit helps connect the F knot to the F one unit and also plays a role in proton transport. Now up to this point we basically see that the F zero region and the F one region are bound to one another at two locations by two structures.