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
![](/ecod/img/m.gif)
![](/ecod/img/p.gif)
![](/ecod/img/p.gif)
![](/ecod/img/m.gif)
Representatives:
e1twfB7[B:542-630]
nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
DNA-DIRECTED RNA POLYMERASE II 140 KDA POLYPEPTIDE ; X-RAY DIFFRACTION 2.3Å
e7fjiB6[B:499-589] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7fjjB6[B:499-589] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7oo3B6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7oobB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7oopB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7opcB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7opdB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7oznB5[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7oznN5[N:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ozoB5[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ozoN5[N:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ozpB5[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ozpN5[N:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7pksB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7rimB7[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 2.9Å
e7ml2B2[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ml0B5[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ml1B4[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ripB2[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 3.270Å
e7riqB6[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 2.960Å
e7riwB6[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 3.17Å
e7rixB1[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 3.3Å
e7riyB7[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; X-RAY DIFFRACTION 3.630Å
e7ml4B5[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7meib5[b:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7meiB2[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7mk9B2[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7mkab2[b:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7z1lB5[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z1mB5[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z1nB5[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z1oB7[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7xn7B3[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xseB4[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xsxB4[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xszB4[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xtdB7[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xt7B3[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7xtiB4[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ui9B3[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7uifB3[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7uioAB6[AB:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7uioBB2[BB:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e8ceoB5[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7zs9B4[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7zsaB4[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e7zsbB4[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e8gxqPB5[PB:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8gxsPB6[PB:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7uncB1[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7undB7[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7zwdB5[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7zx7B2[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7zx8B4[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8h0vB5[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8h0wB5[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8bvwB3[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8byqB6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8bz1B6[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e7ycx22[2:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase subunit beta ; ELECTRON MICROSCOPY
e8cenB1[B:542-630] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase II subunit RPB2 ; ELECTRON MICROSCOPY
e8iueB2[B:499-589] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e8iuhB3[B:499-589] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e8bwsB2[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z0hB1[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z2zB3[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z30B4[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e7z31B1[B:517-605] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase III subunit RPC2 ; ELECTRON MICROSCOPY
e8hilB1[B:532-620] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-dependent RNA polymerase IV and V subunit 2 ; ELECTRON MICROSCOPY
e8himB6[B:532-620] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
DNA-directed RNA polymerase IV and V subunit 2 ; ELECTRON MICROSCOPY
e8p4eB2[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e8p4aB1[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e8a40B1[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e8b3dB7[B:529-618] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e8oeuB7[B:606-695] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e8hyjB4[B:537-624] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e8ityB2[B:499-589] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
e7wbvB3[B:535-623] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
; ELECTRON MICROSCOPY
Previous![](/ecod/img/p.gif)
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