University of Michigan, Ann Arbor, MI 48109 USA
| 1.1. | Alpha-helical transmembrane (47 superfamilies) | |
| 1.2. | Beta-barrel transmembrane (15 superfamilies) | |
| 2.1. | All alpha monotopic/peripheral (29 superfamilies) | |
| 2.2. | All beta monotopic/peripheral (40 superfamilies) | |
| 2.3. | Alpha/Beta monotopic/peripheral (18 superfamilies) | |
| 2.4. | Alpha + Beta monotopic/peripheral (13 superfamilies) | |
| 3.1. | Alpha-helical peptides (14 superfamilies) | |
| 3.2. | Beta-hairpin peptides (7 superfamilies) | |
| 3.3. | Pi(Beta)-helical peptides (1 superfamilies) | |
| 3.4. | Nonregular peptides (5 superfamilies) |