Table 3.
The 18 most highly diverse and hence oldest superfamilies. The species column indicates the number of species this superfamily occurs in, the superkingdom column indicates whether the superfamily occurs in eukaryota (E), archaea (A), bacteria (B), and viruses (V), connectivity refers to the number of interaction partners.
| Species | Superkingdoms | Connectivity | SCOP ID | Superfamily |
| 270 | VEBA | 46 | c.37.1 | P-loop containing nucleotide triphosphate hydrolases |
| 193 | EBA | 9 | c.2.1 | NAD(P)-binding Rossmann-fold domains |
| 154 | EBA | 8 | c.55.1 | Actin-like ATPase domain |
| 143 | VEBA | 8 | d.144.1 | Protein kinase-like (PK-like) |
| 135 | EBA | 18 | c.3.1 | FAD/NAD(P)-binding domain |
| 128 | EBA | 38 | b.1.1 | Immunoglobulin |
| 98 | EB | 9 | a.39.1 | EF-hand |
| 90 | VEBA | 11 | a.4.5 | Winged helix DNA-binding domain |
| 66 | EBA | 11 | d.15.4 | 2Fe-2S ferredoxin-like |
| 65 | EB | 8 | d.15.1 | Ubiquitin-like |
| 63 | EBA | 12 | d.58.1 | 4Fe-4S ferredoxins |
| 62 | EBA | 10 | d.142.1 | Glutathione synthetase ATP-binding domain-like |
| 59 | EB | 11 | a.3.1 | Cytochrome c |
| 48 | EB | 6 | a.118.1 | ARM repeat |
| 37 | EBA | 9 | c.1.4 | FMN-linked oxidoreductases |
| 32 | EBA | 7 | d.145.1 | FAD-binding domain |
| 93 | EBA | 14 | c.1.8 | (Trans)glycosidases |
| 55 | EBA | 7 | d.92.1 | Metalloproteases (zincins) catalytic domain |