The SCOPe (Structural Classification of Proteins — extended) database classifies proteins according to their overall shape. Unfortunately, the SCOPe database, which is maintained by the University of California - Berkeley, is scheduled to be shut down in the summer of 2017 due to lack of funding.
This page attempts to categorize Foldit proteins according to the SCOPe classes. In sections below, puzzles shown on the same line involve proteins which should fold to a similar shape.
This page is not being actively maintained as of February 2017.
3D images and distance maps for many proteins from these classes are shown at Distance Maps and http://memorize.com/protein-distance-maps.
For complete lists of player-submitted images of puzzle results, see puzzle results - 379 to 1000 and puzzle results - 1001 and up.
All alpha proteins - SCOPe Class a[]
Mainly helices
DNA/RNA-binding 3-helical bundle[]
core: 3-helices; bundle, closed or partly opened, right-handed twist; up-and down
Homeodomain-like[]
Homeodomain Puzzle 476, Puzzle 481, Puzzle 696
Myb/SANT domain[]
Puzzle 671, Puzzle 685, Puzzle 692
ARID-like[]
Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex[]
3 helices; bundle, closed, right-handed twist; up-and-down: Puzzle 768
VHP, Villin headpiece domain[]
3 short helices; irregular array
VHP[]
VHP Chicken villin
Histone-fold[]
3 helices; long middle helix is flanked at each end with shorter ones
Histone Fold[]
Nucleosome core histones[]
form octamers composed of two copies of each of the four histones: Puzzle 761
4 helical up and down bundle[]
4 helices; bundle, closed or partly opened, left-handed twist; up-and-down
Cytochromes[]
Alpha-catenin/vinculin-like []
4-helical cytokines[]
core: 4 helices; bundle, closed; left-handed twist; 2 crossover connections: Puzzle 515, Puzzle 520, Symmetry_CASP_ROLL_R0007, Puzzle 554
Acyl carrier protein-like[]
4 helices, bundle; helix 3 is shorter than others; up-and-down
Retrovirus capsid dimerization domain-like[]
Dimerization-anchoring domain of cAMP-dependent PK regulatory subunit[]
4 helices; bundle, closed, right-handed twist: Puzzle 672
EF Hand-like[]
4 helices; array of 2 hairpins, opened: Puzzle 754
PTS-regulatory domain, PRD[]
core: 4 helices; bundle, closed, right-handed twist; 1 crossover connection: Puzzle 512, Puzzle 634
All beta proteins - SCOPe Class b[]
mainly sheets
OB fold[]
barrel, closed or partly opened n=5, S=10 or S=8; greek-key
Nucleic acid-binding proteins[]
BC4932-like[]
Immunoglobulin-like beta-sandwich[]
sandwich; 7 strands in 2 sheets; greek-key: Puzzle 452, Puzzle 462, Puzzle 432, Puzzle 437
Immunoglobulin[]
Puzzle 550 V set domains (antibody variable domain-like) Puzzle 474
C1 set domains (antibody constant domain-like) []
Fibronectin type III[]
Puzzle 491, Puzzle 505, Puzzle 507
PKD domain[]
Puzzle 770 (close to 1BR4), Puzzle 788
Transglutaminase, two C-terminal domains[]
Puzzle 461, Puzzle 464, Puzzle 482, Puzzle 485, Puzzle 542, Puzzle 546
ApaG-like[]
Puzzle 408, Puzzle 433, Puzzle 435, Puzzle 442
E set domains[]
Filamin repeat (rod domain) Puzzle 447, Puzzle 459, Puzzle 660
Invasin/intimin cell-adhesion fragments[]
Puzzle 414, Puzzle 416, Puzzle 426, Puzzle 429, Puzzle 668
C2 domain-like[]
sandwich; 8 strands in 2 sheets; greek-key
PHL pollen allergen[]
gamma-Crystallin-like[]
Sandwich; 8 strands in 2 sheets; greek-key duplication: has internal pseudo twofold symmetry Puzzle 766
Supersandwich[]
Puzzle 511, Puzzle 516, Puzzle 518
SH3-like barrel[]
barrel, partly opened; n*=4, S*=8; meander the last strand is interrupted by a turn of 3-10 helix
SH3-domain[]
PDZ domain-like[]
contains barrel, partly opened; n*=4, S*=8; meander; capped by alpha-helix: T-cell_Lymphoma
Lipocalins[]
barrel, closed or opened; n=8, S=12; meander
Fatty acid binding protein-like[]
ten-stranded meander beta-sheet folded upon itself, relates to the common fold by opening the barrel and insertion of beta-hairpin: Puzzle 733
WW domain-like []
core: 3-stranded meander beta-sheet
WW domain[]
Beta clip[]
double-stranded ribbon sharply bent in two places; the ribbon ends form incomplete barrel; jelly-roll
AFP III-like domain[]
duplication: consists of two structural repeats related by pseudo dyad
Type III antifreeze protein, AFP III[]
Alpha and beta proteins (a+b) - SCOPe Class d[]
Mainly antiparallel beta sheets (segregated alpha and beta regions)
Lysozyme-like[]
common alpha+beta motif for the active site region
Lysozyme-like[]
C-type lysozyme Turkey_Egg_Lysozyme
IL8-like[]
beta(3)-alpha
Interleukin 8-like chemokines[]
Viral_Macrophage_Inflammatory_Protein
DNA-binding domain[]
beta(3)-alpha; 2 layers: alpha/beta: Puzzle 751
Dodecin subunit-like[]
beta-alpha-beta(2); 2 layers: alpha/beta; antiparallel beta-sheet: order 132
Amyloid beta a4 protein copper binding domain (domain 2) []
beta-Grasp (ubiquitin-like)[]
core: beta(2)-alpha-beta(2); mixed beta-sheet 2143: Puzzle 784
2Fe-2S ferredoxin-like[]
Cystatin-like[]
alpha-beta(4); helix packs against coiled antiparallel beta-sheet: Puzzle 611
Cystatin/monellin[]
Puzzle 573, Puzzle 580 Cystatins Potato_Multicystatin
dsRBD-like[]
alpha-beta(3)-alpha; 2 layers: alpha/beta: Puzzle 728, Puzzle 730, Puzzle 732
Alpha-lytic protease prodomain-like[]
core: alpha-beta(2)-(alpha)-beta; 2 layers: alpha/beta
Fe-S cluster assembly (FSCA) domain-like[]
NifU C-terminal domain-like[]
GroEL-intermediate domain like[]
3-helical bundle packed against 3-stranded mixed beta-sheet: Puzzle 535, Puzzle 544, Puzzle 547
Ferredoxin-like[]
alpha+beta sandwich with antiparallel beta-sheet; (beta-alpha-beta)x2
HMA, heavy metal-associated domain[]
Killer toxin KP6 alpha-subunit[]
RNA-binding domain, RBD[]
beta(3)-alpha; 2 layers: alpha/beta Canonical RBD Puzzle 417, Puzzle 431
Acylphosphatase/BLUF domain-like[]
Acylphosphatase-like Puzzle 506
Probable bacterial effector-binding domain[]
duplication of beta-alpha-beta(2) motif: antiparallel beta sheet forms barrel (n=6, S=12)
Probable bacterial effector-binding domain[]
Gyrase inhibitory protein Gyr Puzzle 438, Puzzle 446, Puzzle 473, Puzzle 498
Secretion chaperone-like[]
alpha-beta(3)-alpha-beta(2)-alpha; 2 layers: alpha/beta
Type III secretory system chaperone-like[]
Type III secretory system chaperone[]
beta-Grasp (ubiquitin-like)[]
core: beta(2)-alpha-beta(2); mixed beta-sheet 2143: Puzzle 469
Immunoglobulin-binding domains[]
Pili subunits[]
contains very long N-terminal helix, which end is packed against beta-sheet
Pili subunits[]
Profilin-like[]
2 alpha-helices and 5-stranded antiparallel sheet: order 21543; 3 layers: alpha/beta/alpha
PYP-like sensor domain (PAS domain)[]
alpha-beta(2)-alpha(2)-beta(3): Puzzle 517, Puzzle 521, Puzzle 524
GYF/BRK domain-like[]
beta(2)-alpha-beta(2)-alpha; 2 layers, alpha/beta
GYF domain[]
TBP-like[]
Bet v1-like[]
Protein kinase-like (PK-like)[]
gpW/XkdW-like[]
alpha-beta(2)-alpha; antiparallel hairpin: Puzzle 500
SufE/NifU[]
alpha(2)-beta(3)-alpha(3); 2 layers alpha/beta, 3-stranded antiparallel beta-sheet; order 123: Puzzle 551
Alpha and beta proteins (a/b) - SCOPe Class c[]
Mainly parallel beta sheets (beta-alpha-beta units)
The "swivelling" beta/beta/alpha domain[]
3 layers: b/b/a; the central sheet is parallel, and the other one is antiparallel; there are some variations in topology
GroEL apical domain like[]
GroEL-like chaperone, apical domain Puzzle 412
Leucine-rich repeat, LRR (right-handed beta-alpha superhelix)[]
2 curved layers, a/b; parallel beta-sheet; order 1234...N: Puzzle 527, Puzzle 534
Flavodoxin-like[]
3 layers, a/b/a; parallel beta-sheet of 5 strand, order 21345
CheY-like[]
Puzzle 434, Puzzle 436, Puzzle 440, Puzzle 445, Puzzle 449, Puzzle 453, Puzzle 454, Puzzle 488, Puzzle 502
[]
SGNH hydrolase[]
Phosphotyrosine protein phosphatases I-like[]
3 layers: a/b/a; parallel beta-sheet of 4 strands, order 2134
PTS system IIB component-like[]
Thioredoxin fold[]
core: 3 layers, a/b/a; mixed beta-sheet of 4 strands, order 4312; strand 3 is antiparallel to the rest
Thioredoxin-like[]
core: 3 layers, a/b/a; mixed beta-sheet of 4 strands, order 4312; strand 3 is antiparallel to the rest: Puzzle 621
Thioltransferase[]
Puzzle 455, Puzzle 622, Puzzle 467, Puzzle 739 had no images shared, Puzzle 746
Txnl5-like []
Puzzle 457, Puzzle 463, Puzzle 480, Puzzle 486
Nucleotide-diphospho-sugar transferases[]
Membrane and cell surface proteins and peptides - SCOPe Class f[]
Family A G protein-coupled receptor-like[]
core: up-and-down bundle of seven transmembrane helices tilted 20 degrees with respect to the plane of the membrane Puzzle 726 had no results shared.
Small proteins - SCOPe Class g[]
Insulin-like[]
nearly all-alpha can be classified as disulfide-rich: Puzzle 707
Knottins (small inhibitors, toxins, lectins)[]
disulfide-bound fold; contains beta-hairpin with two adjacent disulfides
Scorpion toxin-like[]
Short-chain scorpion toxins Scorpion_Toxin, Puzzle 762
Defensin-like[]
Disulfide-rich fold, nearly all-beta
Defensin-like[]
Puzzle 548, Puzzle 624, Platypus Venom, Puzzle 774
Crambin-like[]
disulfide-rich alpha+beta fold: Puzzle 781, Puzzle 790