A systematic rationalization of the hundreds of proteins harboring iron-sulfur clusters and able to exhibit the most diverse biological functions is missing. In this picture we have already reviewed structure/electrochemistry of metalloproteins expressing single types of iron-sulfur centres [namely, (Fe(Cys)(4)), {[Fe2S2](Cys)(4)}, {[Fe2S2](Cys)(3)(X)} (X = Asp, Arg, His), {[Fe2S2](Cys)(2)(His)(2)}, {[Fe3S4](Cys)(3)}, {[Fe4S4](CYs)(4)} and {[Fe4S4](S-Cys(gamma))(3)(nonthiolate ligand)}] and their synthetic analogs. Recently we are focussing on structure/electrochemistry of metalloproteins containing iron-sulfur centres of different nuclearities. Having started such a subject with proteins harboring [4Fe-4S] and [2Fe-2S] (Zanello, 2017c) as well as [4Fe-4S] and [3Fe-4S] (Zanello, in press) clusters, we now provide the state of art of proteins harboring [4Fe-4S], [3Fe-4S] and [2Fe-2S] clusters, a subject that resulted strictly limited to enzymes active in the respiratory Complex II.