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




Representatives:
e2fsrA1[A:4-167]
nonrep
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ACETYLTRANSFERASE ; ligands: FMT,PEG ; X-RAY DIFFRACTION 1.52Å
e2fckA1[A:1-178]
nonrep
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ribosomal-protein-serine acetyltransferase, putative ; ligands: GOL,NO3 ; X-RAY DIFFRACTION 1.7Å
e5ktdA1[A:2-188] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FdhC ; ligands: COA,EDO,MG,QUH ; X-RAY DIFFRACTION 1.90Å
e5ktaA1[A:2-179] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FdhC ; ligands: DMS,SO4 ; X-RAY DIFFRACTION 1.89Å
e3juwA1[A:5-171] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable GnaT-family acetyltransferase ; ligands: SO4 ; X-RAY DIFFRACTION 2.100Å
e3juwB1[B:5-171] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable GnaT-family acetyltransferase ; ligands: SO4 ; X-RAY DIFFRACTION 2.100Å
e3juwC1[C:5-171] Image Pymol Jmol Links: PDB, SCOP, CATH
Probable GnaT-family acetyltransferase ; ligands: SO4 ; X-RAY DIFFRACTION 2.100Å
e3eo4A1[A:341-502] Image Pymol Jmol Links: PDB, SCOP, CATH
UNCHARACTERIZED PROTEIN MJ1062 ; ligands: MES,PG6 ; X-RAY DIFFRACTION 2.19Å
e3eo4C1[C:349-502] Image Pymol Jmol Links: PDB, SCOP, CATH
UNCHARACTERIZED PROTEIN MJ1062 ; ligands: EDO,MES ; X-RAY DIFFRACTION 2.19Å
e3eo4D1[D:341-502] Image Pymol Jmol Links: PDB, SCOP, CATH
UNCHARACTERIZED PROTEIN MJ1062 ; ligands: EDO,MES ; X-RAY DIFFRACTION 2.19Å
e2zw6A1[A:8-175] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.5Å
e2zw4A4[A:8-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: COA,SO4 ; X-RAY DIFFRACTION 2.7Å
e2zw4B4[B:8-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.7Å
e2zw4C4[C:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: COA,SO4 ; X-RAY DIFFRACTION 2.7Å
e2zw7B4[B:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: BLM ; X-RAY DIFFRACTION 2.8Å
e2zw5A4[A:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: COA ; X-RAY DIFFRACTION 2.4Å
e2zw7A4[A:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: BLM,COA ; X-RAY DIFFRACTION 2.8Å
e2zw4D4[D:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.7Å
e2zw5B4[B:9-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: COA ; X-RAY DIFFRACTION 2.4Å
e2zw6B4[B:8-177] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
BLEOMYCIN ACETYLTRANSFERASE ; ligands: SO4 ; X-RAY DIFFRACTION 2.5Å
e3eo4B2[B:351-502] Image Pymol Jmol Links: PDB, SCOP, CATH
UNCHARACTERIZED PROTEIN MJ1062 ; ligands: EDO,MES ; X-RAY DIFFRACTION 2.19Å
e4xpkA1[A:0-150] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
N-Acetyltransferase, PseH ; X-RAY DIFFRACTION 1.95Å
e4xplA1[A:1-150] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
N-Acetyltransferase, PseH ; ligands: ACO ; X-RAY DIFFRACTION 1.95Å
e5ktcA1[A:2-188] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
FdhC ; ligands: COA,EDO,FUH,MG ; X-RAY DIFFRACTION 1.8Å
e6eddB1[B:0-192] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase PA3944 ; ligands: COA,EDO,TRS,UNX ; X-RAY DIFFRACTION 1.550Å
e6eddA1[A:9-192] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase PA3944 ; ligands: COA,EDO,UNX ; X-RAY DIFFRACTION 1.550Å
e6edvA1[A:9-192] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase PA3944 ; ligands: CA,COA,EDO ; X-RAY DIFFRACTION 1.350Å
e7kppA1[A:9-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: COA,EDO,UNX ; X-RAY DIFFRACTION 1.450Å
e7kppB1[B:0-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: COA,EDO,UNX ; X-RAY DIFFRACTION 1.450Å
e7kpsA1[A:9-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: ACO,COA,EDO,TRS ; X-RAY DIFFRACTION 1.800Å
e7kpsB1[B:8-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: ACO,COA,EDO,PEG,PGE,TRS ; X-RAY DIFFRACTION 1.800Å
e7kyeA1[A:9-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: COA,EDO,NHE ; X-RAY DIFFRACTION 1.930Å
e7kyjA1[A:8-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: ACT,COA,UNX,ZN ; X-RAY DIFFRACTION 2.000Å
e7kyjB1[B:-1-192] Image Pymol Jmol Links: PDB, SCOP, CATH
Acetyltransferase PA3944 ; ligands: ACT,COA,EDO,UNX,ZN ; X-RAY DIFFRACTION 2.000Å
e4avaA2[A:145-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
LYSINE ACETYLTRANSFERASE ; ligands: ACO,ACT,EDO,MG,PEG ; X-RAY DIFFRACTION 1.7Å
e4avbA4[A:145-332] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
LYSINE ACETYLTRANSFERASE ; ligands: ACO,EDO,PEG ; X-RAY DIFFRACTION 1.8Å
e4avcA4[A:145-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
LYSINE ACETYLTRANSFERASE ; ligands: ACO ; X-RAY DIFFRACTION 2.81Å
e4avbB4[B:145-332] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
LYSINE ACETYLTRANSFERASE ; ligands: ACO,ACT,EDO,PEG ; X-RAY DIFFRACTION 1.8Å
e4avcB4[B:145-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
LYSINE ACETYLTRANSFERASE ; ligands: ACO,EDO,PEG ; X-RAY DIFFRACTION 2.81Å
e4ollA1[A:142-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase Pat ; ligands: CA ; X-RAY DIFFRACTION 1.900Å
e4onuA1[A:142-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase Pat ; ligands: CA ; X-RAY DIFFRACTION 2.250Å
e4orfA1[A:142-333] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
Acetyltransferase Pat ; ligands: CL ; X-RAY DIFFRACTION 2.000Å
e1s7kA1[A:3-31,A:51-176]
nonrep
Image
Pymol
Jmol Links:
PDB,
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CATH, PubMed,
DOI
ACETYL TRANSFERASE ; X-RAY DIFFRACTION 1.8Å

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