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




Representatives:
e1b04B1[B:1-311]
* nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
PROTEIN (DNA LIGASE) ; X-RAY DIFFRACTION 2.80Å
e1v9pB3[B:2001-2317] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA LIGASE ; ligands: AMP ; X-RAY DIFFRACTION 2.9Å
e1v9pA3[A:1-317] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA LIGASE ; ligands: AMP ; X-RAY DIFFRACTION 2.9Å
e1dgsB3[B:2001-2314] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA LIGASE ; ligands: AMP ; X-RAY DIFFRACTION 2.9Å
e1b04A1[A:2-311] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
PROTEIN (DNA LIGASE) ; X-RAY DIFFRACTION 2.80Å
e1dgsA3[A:1-314] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA LIGASE ; ligands: AMP ; X-RAY DIFFRACTION 2.9Å
e3pn1A1[A:1-318] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: IVH,IWH ; X-RAY DIFFRACTION 2.00Å
e3uq8A1[A:3-324] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: AMP,NAD ; X-RAY DIFFRACTION 1.7Å
e1zauA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: AMP ; X-RAY DIFFRACTION 3.15Å
e4glwB1[B:1-275] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: 0XT,NMN,SO4 ; X-RAY DIFFRACTION 2.000Å
e4glxA4[A:3-316] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: 0XS,SO4 ; X-RAY DIFFRACTION 1.900Å
e3sgiA3[A:8-327] Image Pymol Jmol Links: PDB, SCOP, CATH
DNA LIGASE ; ligands: AMP ; X-RAY DIFFRACTION 3.5Å
e2owoA4[A:1-316] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: AMP,SO4 ; X-RAY DIFFRACTION 2.300Å
e4uctA1[A:1-318] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: 5U1,IWH ; X-RAY DIFFRACTION 2.10Å
e4ucuA1[A:1-318] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: 8HC,IWH ; X-RAY DIFFRACTION 2.10Å
e4ucvA1[A:1-318] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: I6G,IWH ; X-RAY DIFFRACTION 2.60Å
e4ucoA1[A:1-317] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: D41,IWH ; X-RAY DIFFRACTION 2.50Å
e4ucrA1[A:1-317] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: IWH,JCF ; X-RAY DIFFRACTION 2.15Å
e4ucsA1[A:1-317] Image Pymol Jmol Links: PDB, SCOP, CATHDOI
DNA LIGASE ; ligands: 9MJ,IWH ; X-RAY DIFFRACTION 1.90Å
e4ufzA1[A:1-317] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA LIGASE ; ligands: IA7,IWH ; X-RAY DIFFRACTION 2.33Å
e5tt5A1[A:1-316] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase ; ligands: MG,NAD ; X-RAY DIFFRACTION 1.55Å
e6kduA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: AMP,NMN,SO4 ; X-RAY DIFFRACTION 2.200Å
e6kjmA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: AMP,NMN,SO4 ; X-RAY DIFFRACTION 2.200Å
e6kkvA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: DKR,SO4 ; X-RAY DIFFRACTION 2.560Å
e6krhA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: AMP,NMN,SO4 ; X-RAY DIFFRACTION 2.600Å
e6kscA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: AMP,SO4 ; X-RAY DIFFRACTION 2.400Å
e6ksdA1[A:8-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: NMN,SO4 ; X-RAY DIFFRACTION 2.500Å
e7k72A1[A:9-326] Image Pymol Jmol Links: PDB, SCOP, CATH
DNA ligase A ; ligands: CA,MG,MPD,NAD ; X-RAY DIFFRACTION 2.050Å
e7k72B1[B:10-326] Image Pymol Jmol Links: PDB, SCOP, CATH
DNA ligase A ; ligands: CA,MG,MPD,NAD ; X-RAY DIFFRACTION 2.050Å
e7k72C1[C:9-326] Image Pymol Jmol Links: PDB, SCOP, CATH
DNA ligase A ; ligands: MG,MPD,NAD ; X-RAY DIFFRACTION 2.050Å
e7k72D1[D:9-326] Image Pymol Jmol Links: PDB, SCOP, CATH
DNA ligase A ; ligands: MG,MPD,NAD ; X-RAY DIFFRACTION 2.050Å
e6lw8A1[A:9-328] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA ligase A ; ligands: EWO,GOL,SO4 ; X-RAY DIFFRACTION 2.400Å

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