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




Representatives:
e1k8kD1[D:1-120]
nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
ARP2/3 COMPLEX 34 KDA SUBUNIT ; X-RAY DIFFRACTION 2.0Å
e1k8kD2[D:121-284]
nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
ARP2/3 COMPLEX 34 KDA SUBUNIT ; X-RAY DIFFRACTION 2.0Å
e2p9lD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.650Å
e2p9uD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.750Å
e2p9nD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.850Å
e1u2vD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Arp2/3 Complex 34Kda Subunit ; X-RAY DIFFRACTION 2.55Å
e2p9iD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.430Å
e2p9kD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.580Å
e1tyqD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ARP2/3 COMPLEX 34KDA SUBUNIT ; X-RAY DIFFRACTION 2.55Å
e2p9sD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.68Å
e2p9pD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.900Å
e3dxkD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ACTIN-RELATED PROTEIN 2/3 COMPLEX SUBUNIT 2 ; X-RAY DIFFRACTION 2.7Å
e3dwlD1[D:123-303] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ACTIN-RELATED PROTEIN 2/3 COMPLEX SUBUNIT 2 ; X-RAY DIFFRACTION 3.78Å
e3ukrD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.48Å
e3dxmD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ACTIN-RELATED PROTEIN 2/3 COMPLEX SUBUNIT 2 ; X-RAY DIFFRACTION 2.85Å
e3rseD2[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ACTIN-RELATED PROTEIN 2/3 COMPLEX SUBUNIT 2 ; X-RAY DIFFRACTION 2.65Å
e3dwlI1[I:123-303] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
ACTIN-RELATED PROTEIN 2/3 COMPLEX SUBUNIT 2 ; X-RAY DIFFRACTION 3.78Å
e3uleD2[D:121-281] Image Pymol Jmol Links: PDB, SCOP, CATH
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.500Å
e3ukuD2[D:121-277] Image Pymol Jmol Links: PDB, SCOP, CATH
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 2.75Å
e4jd2D1[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 3.08Å
e4xeiD1[D:121-282] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 3.874Å
e4xf2D1[D:121-284] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 5.0Å
e4xf2W2[W:121-284] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 5.0Å
e6decD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 4.6Å
e6decK1[K:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; X-RAY DIFFRACTION 4.6Å
e6uhcD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e6w17D2[D:123-301] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e6yw6D1[D:121-284] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e6w18D1[D:123-300] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e6yw7D1[D:121-284] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e7aqkd1[d:121-281] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2, ArpC2 ; ELECTRON MICROSCOPY
e7jpnD1[D:121-284] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e7tptD2[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e8e9bD1[D:123-317] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Actin-related protein 2/3 complex subunit 2 ; ELECTRON MICROSCOPY
e7t5qD1[D:121-283] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e8tahD1[D:121-285] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
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