Evolutionary classification of protein domain structures
alpha arraysalpha-helix arrays with mainly perpendicular helices
alpha bundlesalpha-helix bundles with mainly parallel helices
alpha superhelicesrepeating alpha-helix hairpins form a superhelix
alpha duplicates or obligate multimersalpha duplicates or monomers associate together to form a compact domain
alpha complex topologyalpha domain with complex and unique topology that cannot be described as array or bundle or superhelix
beta barrelssingle beta-sheet folded upon itself to form a barrel
beta meanderssingle beta-sheet with mainly meander topology
beta sandwichestwo beta-sheets stacked together to form a sandwich




Representatives:
e3lzlA1[A:2-158]
nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
P19 protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.45Å
contains an N-terminal additional strand
e3nrpA1[A:2-153] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; X-RAY DIFFRACTION 1.6Å
e3pjlA1[A:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH
34 kDa membrane antigen ; ligands: CO,EDO,SO4 ; X-RAY DIFFRACTION 1.7Å
e2o6cA1[A:28-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,EDO ; X-RAY DIFFRACTION 1.7Å
e2o6cB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,SO4 ; X-RAY DIFFRACTION 1.7Å
e2o6dB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,SO4,ZN ; X-RAY DIFFRACTION 1.86Å
e2o6eB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,SO4,ZN ; X-RAY DIFFRACTION 1.87Å
e2o6fA1[A:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,EDO,SO4 ; X-RAY DIFFRACTION 1.63Å
e2o6fB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,SO4 ; X-RAY DIFFRACTION 1.63Å
e2o6dA1[A:28-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,EDO,SO4,ZN ; X-RAY DIFFRACTION 1.86Å
e2o6eA1[A:28-185] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
34 kDa membrane antigen ; ligands: CL,EDO,SO4,ZN ; X-RAY DIFFRACTION 1.87Å
e3lzlB1[B:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU ; X-RAY DIFFRACTION 1.45Å
e3lznA1[A:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: SO4,ZN ; X-RAY DIFFRACTION 1.59Å
e3lznB1[B:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: SO4,ZN ; X-RAY DIFFRACTION 1.59Å
e3lzoA1[A:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.65Å
e3lzoB1[B:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.65Å
e3lzpA1[A:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.65Å
e3lzpB1[B:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.65Å
e3lzqA1[A:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,MN,SO4 ; X-RAY DIFFRACTION 1.41Å
e3lzqB1[B:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,MN,SO4 ; X-RAY DIFFRACTION 1.41Å
e3lzrA1[A:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,MN,SO4 ; X-RAY DIFFRACTION 2.73Å
e3lzrB1[B:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 protein ; ligands: CU,MN,SO4 ; X-RAY DIFFRACTION 2.73Å
e3nrpB1[B:2-153] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; X-RAY DIFFRACTION 1.6Å
e3nrpC1[C:2-152] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; X-RAY DIFFRACTION 1.6Å
e3nrpD1[D:2-152] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; X-RAY DIFFRACTION 1.6Å
e3nrqA1[A:4-153] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; ligands: CU ; X-RAY DIFFRACTION 1.7Å
e3nrqB1[B:4-152] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PERIPLASMIC PROTEIN-PROBABLY INVOLVED IN HIGH-AFFINITY FE2+ TRANSPORT ; ligands: CU ; X-RAY DIFFRACTION 1.7Å
e3pjlB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH
34 kDa membrane antigen ; ligands: CO,EDO,SO4 ; X-RAY DIFFRACTION 1.7Å
e3pjnB1[B:29-185] Image Pymol Jmol Links: PDB, SCOP, CATH
34 kDa membrane antigen ; ligands: ZN ; X-RAY DIFFRACTION 1.7Å
e3pjnA1[A:28-185] Image Pymol Jmol Links: PDB, SCOP, CATH
34 kDa membrane antigen ; ligands: EDO,SO4,ZN ; X-RAY DIFFRACTION 1.7Å
e4nwnB1[B:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnD1[D:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnF1[F:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnH1[H:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnJ1[J:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnL1[L:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnN1[N:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnP1[P:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnR1[R:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnT1[T:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnV1[V:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e4nwnX1[X:2-158] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
PROPANEDIOL UTILIZATION: POLYHEDRAL BODIES PDUT ; X-RAY DIFFRACTION 4.5Å
e5i0vB1[B:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Protein P19 ; ligands: CL,CU,FE ; X-RAY DIFFRACTION 1.650Å
e5i0wB1[B:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 ; ligands: CL,CU1,FE2,TAM ; X-RAY DIFFRACTION 1.550Å
e5i0vA1[A:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Protein P19 ; ligands: CL,CU,FE ; X-RAY DIFFRACTION 1.650Å
e5i0wA1[A:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
P19 ; ligands: CL,CU1,TAM ; X-RAY DIFFRACTION 1.550Å
e5i0xA1[A:1-153] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Periplasmic protein-probably involved in high-affinity Fe2+ transport ; ligands: CU ; X-RAY DIFFRACTION 1.500Å
e5i0xB1[B:3-160] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Periplasmic protein-probably involved in high-affinity Fe2+ transport ; ligands: CU ; X-RAY DIFFRACTION 1.500Å
e5i0yA1[A:3-152] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Periplasmic protein-probably involved in high-affinity Fe2+ transport ; ligands: CU ; X-RAY DIFFRACTION 1.400Å
e5i0yB1[B:3-160] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Periplasmic protein-probably involved in high-affinity Fe2+ transport ; ligands: CU ; X-RAY DIFFRACTION 1.400Å
e6wedA1[A:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 1.900Å
e6wedB1[B:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU ; X-RAY DIFFRACTION 1.900Å
e6weeA1[A:2-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.300Å
e6weeC1[C:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.300Å
e6weeB1[B:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.300Å
e6weeD1[D:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,SO4 ; X-RAY DIFFRACTION 2.300Å
e6weeE1[E:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,TRS ; X-RAY DIFFRACTION 2.300Å
e6weeF1[F:3-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.300Å
e6wefC1[C:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefD1[D:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefA1[A:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefB1[B:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefE1[E:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefF1[F:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefG1[G:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefH1[H:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.500Å
e6wefI1[I:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefJ1[J:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,SO4 ; X-RAY DIFFRACTION 2.500Å
e6wefK1[K:2-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL ; X-RAY DIFFRACTION 2.500Å
e6wefL1[L:1-159] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Uncharacterized protein ; ligands: CU,GOL,SO4 ; X-RAY DIFFRACTION 2.500Å
e7r5eA1[A:2-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU,MG ; X-RAY DIFFRACTION 2.2Å
e7r5pF1[F:1-155] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,MG ; X-RAY DIFFRACTION 1.68Å
e7r3pA1[A:1-157] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: GOL,PEG,SO4 ; X-RAY DIFFRACTION 1.4Å
e7r3pB1[B:1-157] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: SO4 ; X-RAY DIFFRACTION 1.4Å
e7r3sA1[A:0-158] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: GOL,NA,NI,SO4 ; X-RAY DIFFRACTION 1.79Å
e7r3sB1[B:0-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: NA,NI,SO4 ; X-RAY DIFFRACTION 1.79Å
e7r4uA1[A:0-155] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: GOL,NA,SO4 ; X-RAY DIFFRACTION 1.23Å
e7r4uB1[B:0-162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: NA,SO4 ; X-RAY DIFFRACTION 1.23Å
e7r4vB1[B:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU1 ; X-RAY DIFFRACTION 1.30Å
e7r4zA1[A:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,FE ; X-RAY DIFFRACTION 2.75Å
e7r4zB1[B:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,FE ; X-RAY DIFFRACTION 2.75Å
e7r5eB1[B:0-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU,MG,PEG ; X-RAY DIFFRACTION 2.2Å
e7r5gA1[A:0-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU,MG,PEG ; X-RAY DIFFRACTION 2.2Å
e7r5pA1[A:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,EDO,MG ; X-RAY DIFFRACTION 1.68Å
e7r5pB1[B:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,MG ; X-RAY DIFFRACTION 1.68Å
e7r5pD1[D:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,MG ; X-RAY DIFFRACTION 1.68Å
e7r5pE1[E:1-156] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,MG ; X-RAY DIFFRACTION 1.68Å
e7r4vA1[A:2-155] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU1 ; X-RAY DIFFRACTION 1.30Å
e7r5gB1[B:2-155] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 ; ligands: CU,MG ; X-RAY DIFFRACTION 2.2Å
e7r5pC1[C:2-155] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FtrA-P19 protein ; ligands: CU1,MG ; X-RAY DIFFRACTION 1.68Å

Pseudo group of domains that do not map to PFam family profiles. Domains inside should not be considered as in one family.
beta duplicates or obligate multimersbeta duplicates or monomers associate together to form a compact domain
beta complex topologybeta domains with complex and unique topology that cannot be described as barrel or sandwich or meander
a+b two layersone alpha-helix layer and one beta-sheet layer
a+b three layersone mainly antiparallel beta-sheet layer sandwiched between two alpha-helix layers
a+b four layerstwo beta-sheet layers sandwiched between two alpha-helix layers
a+b complex topologyalpha and beta domain with complex and unique topology that cannot be described in layers
a+b duplicates or obligate multimersalpha and beta duplicates or monomers associated together to form a compact domain
a/b barrelsrepeating beta-alpha units form a barrel
a/b three-layered sandwichesrepeating beta-alpha units form a sandwich with a mainly parallel beta-sheet layer stacked between two alpha-helix layers
mixed a+b and a/balpha and beta domain consists of both a+b and a/b regions
few secondary structure elementsstabilized by cofactors or disulfides
extended segmentsextended, non-globular segments, frequently bind to other proteins to form complexes