Table 1. Representation of known protein folds in 248 PSI structures from DUF families.
| Fold | Number of Representatives in 248 DUFs | Number of Previously Known Protein Families with This Fold in SCOP Database |
| Ferredoxin-like | 8 | 111 |
| DNA/RNA-binding 3-helical bundle | 7 | 102 |
| TIM αβ-barrel | 3 | 99 |
| Immunoglobulin-like β-sandwich | 4 | 55 |
| S-adenosyl-L-methionine-dependent methyltransferase | 6 | 52 |
| Alpha/alpha superhelix | 3 | 51 |
| Flavodoxin-like | 4 | 45 |
| Double-stranded β-helix | 5 | 40 |
| SH3-like barrel | 2 | 37 |
| Four-helical up-and-down bundle | 3 | 36 |
| α/β hydrolase | 2 | 35 |
| Restriction endonuclease-like | 2 | 33 |
| OB-fold | 2 | 30 |
| Rubredoxin-like | 3 | 28 |
| Long alpha hairpin | 2 | 24 |
| Beta-Grasp (ubiquitin-like) | 2 | 24 |
| Thioredoxin fold | 3 | 23 |
| TBP-like | 5 | 17 |
| Cysteine proteinases | 3 | 16 |
| Spectrin repeat-like | 2 | 16 |
| Immunoglobulin/albumin-binding domain-like | 2 | 13 |
| Bromodomain-like | 2 | 12 |
| NAD(P)-binding Rossmann-fold domains | 2 | 12 |
| Nucleotidyltransferase | 2 | 11 |
| Bacillus chorismate mutase-like | 2 | 10 |
| Ferritin-like | 2 | 10 |
| Anticodon-binding domain-like | 2 | 9 |
| DSRBD-like | 2 | 8 |
| Fwde/GAPDH domain-like | 2 | 8 |
| Lipocalins | 2 | 8 |
| 5-bladed β-propeller | 2 | 7 |
| α/β knot | 2 | 5 |
| Dodecin subunit-like | 2 | 5 |
| T-fold | 2 | 5 |
| Secretion chaperone-like | 3 | 3 |
| Cyclophilin-like | 2 | 3 |
| DSREFH-like | 2 | 2 |
| MK0786-like | 2 | 1 |
| Hcp1-like | 2 | 1 |
| VPA0735-like | 2 | 1 |
| YheA-like | 2 | 1 |
The table contains only folds that are represented at least twice in different DUF families. The folds here cover 114 DUF families (67 known folds were represented by only one DUF structure each and 67 families have novel folds).