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:
e2flzA1[A:1-147]
* nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
CIS-3-CHLOROACRYLIC ACID DEHALOGENASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.75Å
e2fltA1[A:1-117] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
CIS-3-CHLOROACRYLIC ACID DEHALOGENASE ; ligands: LAC ; X-RAY DIFFRACTION 2.1Å
e2flzB1[B:1-145] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
CIS-3-CHLOROACRYLIC ACID DEHALOGENASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.75Å
e3c6vB1[B:-6-140] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable tautomerase/dehalogenase AU4130 ; ligands: NA,SO4 ; X-RAY DIFFRACTION 1.85Å
e3c6vC1[C:-2-140] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable tautomerase/dehalogenase AU4130 ; ligands: CL,NA ; X-RAY DIFFRACTION 1.85Å
e3mf8A1[A:1-117] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Cis-3-chloroacrylic acid dehalogenase ; ligands: SO4 ; X-RAY DIFFRACTION 2.010Å
e2flzC1[C:1-145] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
CIS-3-CHLOROACRYLIC ACID DEHALOGENASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.75Å
e3mf7A2[A:1-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Cis-3-chloroacrylic acid dehalogenase ; X-RAY DIFFRACTION 1.620Å
e3c6vA1[A:-2-140] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable tautomerase/dehalogenase AU4130 ; X-RAY DIFFRACTION 1.85Å
e4u5rB1[B:1-152] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: TRS ; X-RAY DIFFRACTION 1.55Å
e4u5pA1[A:1-140] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: B3P,MG ; X-RAY DIFFRACTION 1.78Å
e4u5pB1[B:1-141] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: B3P,GOL,MG ; X-RAY DIFFRACTION 1.78Å
e4u5pC1[C:1-141] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: B3P,MG ; X-RAY DIFFRACTION 1.78Å
e4u5rA1[A:1-151] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: TRS ; X-RAY DIFFRACTION 1.55Å
e4u5rC1[C:1-151] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ligands: TRS ; X-RAY DIFFRACTION 1.55Å
e5uifA1[A:1-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Ps01740 ; X-RAY DIFFRACTION 2.57Å
e5uifB1[B:1-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Ps01740 ; X-RAY DIFFRACTION 2.57Å
e5uifC1[C:1-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Ps01740 ; X-RAY DIFFRACTION 2.57Å
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