Class: Membrane and cell surface proteins and peptides

Does not include proteins in the immune system

Lineage:

1. Root: scop
2. Class: Membrane and cell surface proteins and peptides
   Does not include proteins in the immune system

Folds:

1. Toxins' membrane translocation domains (5)
   multi-helical domains of various folds which is thought to unfold in the membrane
2. Membrane all-alpha (1)
3. Light-harvesting complex subunits (1)
   membrane all-alpha fold
4. Transmembrane beta-barrels (3)
   not a true fold, gathers together transmembrane barrels of different (n,S)
5. Integral outer membrane protein TolC, efflux pump component (1)
   subunit fold contains tandem repeat of alpha-beta hairpin-alpha(2) motif
   trimeric fold contains barrel (n=12, S=18) formed by beta-hairins, two from each subunit, and a bundle of helices with a channel running through it
6. Leukocidin (pore-forming toxin) (1)
   subunit fold contains beta-sandwich of Ig-like (grek-key) topology
   heptameric fold contains barrel (n=14, S=14) formed by beta-ribbon arms, one from each subunit
7. Lipovitellin-phosvitin complex (1)
8. (Pro)aerolysin, pore-forming lobe (1)
   3 domains: (1) alpha+beta; (2&3) all-beta
9. Perfringolysin (1)
   2 domains: (1) alpha+beta; (2) all-beta, similar to the CalB domain fold but the two last strands are transposed
10. Envelope glycoprotein, central and dimerisation domains (1)
    2 intertwined domains; all-beta and alpha+beta
11. Anthrax protective antigen (1)
    4 domains; I (res. 14-225) and II (226-487) are beta-sandwiches of similar gamma-crystallin like topologies; III (488-594) has a beta-grasp like fold; IV (595-735) has an Ig-like fold