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
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




Representatives:
e4ai6A10[A:2693-2922]
nonrep
Image
Pymol
Jmol Links:
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DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: ADP ; X-RAY DIFFRACTION 3.4Å
e4rh7A8[A:2570-2811]
nonrep
Image
Pymol
Jmol Links:
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CATH, PubMed,
DOI
Green fluorescent protein/Cytoplasmic dynein 2 heavy chain 1 ; ligands: ADP ; X-RAY DIFFRACTION 3.4Å
e3vkhA7[A:2952-3178]
nonrep
Image
Pymol
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DYNEIN HEAVY CHAIN, CYTOPLASMIC ; ligands: ADP ; X-RAY DIFFRACTION 3.8Å
e3j67A8[A:2691-2922]
nonrep
Image
Pymol
Jmol Links:
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CATH, PubMed,
DOI
Dynein motor domain ; ELECTRON MICROSCOPY
e4akgA3[A:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.30Å
e4akgB3[B:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.30Å
e4akhA3[A:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.60Å
e4akhB3[B:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.60Å
e4akiA3[A:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.70Å
e4akiB3[B:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
GLUTATHIONE S-TRANSFERASE CLASS-MU 26 KDA ISOZYME, DYNEIN HEAVY CHAIN CYTOPLASMIC ; ligands: SO4 ; X-RAY DIFFRACTION 3.70Å
e3j68A8[A:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Dynein motor domain ; ELECTRON MICROSCOPY
e4w8fA3[A:2687-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Dynein heavy chain lysozyme chimera ; ligands: ANP ; X-RAY DIFFRACTION 3.54Å
e3qmzA2[A:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Cytoplasmic dynein heavy chain ; X-RAY DIFFRACTION 6.0Å
e3qmzB2[B:2691-2922] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Cytoplasmic dynein heavy chain ; X-RAY DIFFRACTION 6.0Å

Pseudo group of domains that do not map to PFam family profiles. Domains inside should not be considered as in one family.
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