Evolutionary classification of protein domain structures

X - Possible homology level

H - Homology level

T - Topology level

F - Family level

* - Provisional representative

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

X: C-type lectin-like

X: Noncollagenous (NC1) domain of collagen IV

X: RNase A-like

X: Procyclic specific surface antigen-2

X: Helicase Cch N-terminal domain

X: Suppressor of hydroxyurea sensitivity protein 2

X: Immune Mapped Protein 2 (IMP2)

X: USP8 interacting domain

X: Type III R-M system modification subunit target recognition domain

X: Hemolysin II

X: Outer capsid protein VP2 body domain

X: Mitoribosomal protein mS22

X: Putative lipoprotein BA_2398

X: Head and neck region of the ectodomain of paramyxoviruses fusion glycoprotein

X: S2 subunit of coronavirus spike glycoprotein

H: S2 subunit of coronavirus spike glycoprotein

T: S2 subunit of coronavirus spike glycoprotein

Representatives:

e3jclA4[A:731-1118] nonrep Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ELECTRON MICROSCOPY

e5szsA5[A:750-1224] nonrep Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: MAN,NAG ; ELECTRON MICROSCOPY

e5szsB4[B:750-1224] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: MAN,NAG ; ELECTRON MICROSCOPY

e5szsC5[C:750-1224] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: MAN,NAG ; ELECTRON MICROSCOPY

e7n9cB1[B:793-919,B:945-1240] Image Pymol Jmol Links: PDB, SCOP, CATH DOI

Spike glycoprotein ; ELECTRON MICROSCOPY

e7edhA1[A:698-824,A:846-1144] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7mtdB1[B:700-826,B:855-1143] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7n9eB1[B:701-827,B:853-1148] Image Pymol Jmol Links: PDB, SCOP, CATH DOI

Spike glycoprotein ; ELECTRON MICROSCOPY

e7p7aC1[C:701-828,C:852-1149] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sblB1[B:700-828,B:854-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sblC1[C:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sboB1[B:700-828,B:854-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sboC1[C:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbpA1[A:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbpB1[B:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbpC1[C:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbqA1[A:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbqC1[C:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbrA1[A:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbrC1[C:700-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbsA1[A:701-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbsC1[C:701-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbtA1[A:701-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sbtC1[C:701-827,C:848-1162] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sxxA1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sxxC1[C:700-827,C:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sxzA1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sy1A1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sy3A1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sy3C1[C:700-827,C:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7sy7A1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7t9jA1[A:700-827,A:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7t9jB1[B:700-827,B:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7t9kC1[C:700-827,C:856-1147] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ligands: NAG ; ELECTRON MICROSCOPY

e7vx1C1[C:703-827,C:848-1161] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ELECTRON MICROSCOPY

e7vx7C1[C:701-1162] Image Pymol Jmol Links: PDB, SCOP, CATH

e7vxdB1[B:703-827,B:848-1161] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike glycoprotein ; ELECTRON MICROSCOPY

e5w9hA1[A:753-1223] nonrep Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

MERS S ; ligands: NAG ; ELECTRON MICROSCOPY

e6b7nA4[A:558-1017] nonrep Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI

Spike protein ; ligands: NAG ; ELECTRON MICROSCOPY

X: nsP3 zinc-binding domain

X: Herpesvirus UL21 N-terminal domain

X: Cysteine proteinases-like

X: Late protein H7

X: Lmo1499 protein N-terminal domains

X: Lysozyme-like

X: spore cortex-lytic enzyme catalytic domain

X: Nigritoxin N-terminal domain

X: Nigritoxin C-terminal domain

X: ADP-ribosylation

X: Ribosomal protein TL5/L25 C-terminal domain-like

X: Zinc finger FYVE domain-containing protein 9 C-terminal domain

X: Argininosuccinate synthetase-C

X: Aromatic aminoacid monoxygenases, catalytic and oligomerization domains

X: Methionine synthase activation domain-like

X: Nitric oxide (NO) synthase oxygenase domain

X: Metal cation-transporting ATPase, ATP-binding domain

X: Fibrinogen C-terminal domain-like

X: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain

X: LDH C-terminal domain-like

X: Diaminopimelate epimerase-like

X: Anchorless fibronectin/fibrinogen binding protein C-terminal domain

X: Yos9 dimerization domain

X: Peptide deformylase

X: YbaK/ProRS associated domain

X: CoA-dependent acyltransferases

X: alpha/beta-Hammerhead/Barrel-sandwich hybrid

X: DNA mimic protein DMP12-like

X: Hypothetical protein HI1480

X: RuBisCo LSMT C-terminal, substrate-binding domain

X: 5'-nucleotidase (syn. UDP-sugar hydrolase), C-terminal domain

X: Cell cycle regulatory proteins

X: Conserved core of transcriptional regulatory protein vp16

X: Nitrile hydratase alpha chain

X: Rotavirus NSP2 fragment, N-terminal domain

X: VSV matrix protein

X: ssRNA bacteriophage MS2 maturation protein

X: YopH tyrosine phosphatase N-terminal domain

X: Hsp33 domain

X: Outer capsid protein sigma 3-related

X: mRNA triphosphatase CET1-related

X: Phosphoinositide phosphatase SAC1 N-terminal domain

X: ParB/Sulfiredoxin

X: Aha1/BPI domain-like

X: lantibiotic self-resistance lipoprotein MlbQ

X: Transcription factor NusA, N-terminal domain

X: N-terminal subdomain in DNA replication initiator (cdc21/cdc54)

X: N-terminal domain in beta subunit of DNA dependent RNA-polymerase

X: insertion domain in beta subunit of DNA dependent RNA-polymerase

X: barrel domain in beta subunit of DNA dependent RNA-polymerase

X: inserted a+b domain in yeast RNA polymerase beta subunit

X: C-terminal domain in beta subunit of DNA dependent RNA-polymerase

X: N-terminal domain in RNA-polymerase beta-prime subunit

X: Helical hairpin insertion in E. coli DNA-directed RNA polymerase beta subunit

X: first helical domain in RNA-polymerase beta-prime subunit

X: second helical domain in RNA-polymerase beta-prime subunit

X: helical domain in yeast RNA-polymerases

X: central helical domain in RNA-polymerase beta-prime subunit

X: Sandwich domain in replication terminator protein (Tus)

X: Insertion domain in replication terminator protein (Tus)

X: a+b domain in virulence-associated V antigen

X: Ribonuclease P protein subunit p40

X: a+b domain in membrane penetration protein mu1

X: Inner layer core protein p3-related

X: Major inner capsid protein P1

X: L-A virus major coat protein-related

X: Major capsid protein VP5

X: MoeA domain II

X: DNA methylase specificity domain

X: L,D-transpeptidase pre-catalytic domain-like

X: ORC1-binding domain

X: BTG domain-like

X: DUSP, domain in ubiquitin-specific proteases

X: STIV B116-like

X: TBP-interacting protein C-terminal domain-like

X: N-terminal domain in viral ssDNA binding protein

X: first a+b domain in acetyl-CoA synthase

X: second a+b domain in acetyl-CoA synthase

X: insertion domain in bacteriophage phi29 DNA polymerase

X: linker domain in MalF N-terminal region

X: barrel domain in MalF N-terminal region

X: C-terminal a+b domain in Poly(A) polymerase catalytic subunit

X: Domain II in tail sheath protein Gp18

X: Flagellar protein FlgA N-terminal domain-like

X: N0 domain in phage tail proteins and secretins-like

X: C-terminal insertion domain in phage tail proteins

X: Hypothetical protein TA0956

X: Necrosis and ethylene-inducing peptide 1-like proteins

X: Envelope glycoprotein GP1

X: Arenavirus glycoprotein GP2

X: Uncharacterized protein yutD

X: Myosin VI cargo binding domain

X: gH main domain

X: bacteriophage phiKZ gp29PR

X: Regulatory domain of isocitrate dehydrogenase kinase/phosphatase

X: Baseplate wedge protein gp7 domain II

X: Reovirus guanylyltransferase (GTase)

X: Reovirus turret protein bridge domain

X: Adenine deaminase 2 C-terminal domain

X: Insertion domain in vaccinia virus scaffolding protein D13

X: Insertion domain in O-GlcNAc transferase

X: Insertion domain in Adenovirus penton base protein

X: Membrane-associated protein VP24

X: Envelope glycoprotein GP1

X: DUF2666 family proteins

X: Primosome assembly protein PriA 3' DNA-binding domain

X: RapA C-terminal domain

X: Polymerase acidic protein

X: Mediator of RNA polymerase II transcription submodule Med7N/31

X: Mediator co-activator domain 1 of Gal11/med15

X: Mediator of RNA polymerase II transcription subunit 11

X: Mediator of RNA polymerase II transcription subunit 22

X: Mediator of RNA polymerase II transcription subunit 8

X: Mediator of RNA polymerase II transcription subunit 17

X: Cascade subunit Csa5

X: Scaffolding protein GPB

X: Capsid protein

X: RNAi polymerase N-terminal domain

X: Tomato mosaic virus helicase N-terminal domain

X: Oncogenic effector CagA meander beta sheet domain

X: Tetrahydrodipicolinate N-succinyletransferase N-terminal domain

X: Transcription factor tau 60 kDa subunit

X: hypothetical protein BF0379 C-terminal domain

X: conserved hypothetical protein MTH0776

X: C-terminal domain of BipA

X: C-terminal domain of cytoplasmic dynein heavy chain

X: Protein kinase/SAICAR synthase/ATP-grasp

X: 6-carboxyhexanoate-CoA ligase

X: Rifampin phosphotransferase RPH-Lm middle domain

X: TFB5-related

X: Hypothetical protein ORF126

X: FAD-binding domain-like

X: Hect, E3 ligase catalytic domain

X: E3 ubiquitin-protein ligase SopA catalytic domain

X: Uridine diphospho-N-Acetylenolpyruvylglucosamine reductase, MurB, C-terminal domain

X: Prim-pol domain

X: Methenyltetrahydromethanopterin cyclohydrolase

X: H-NOX domain

X: pathogenicity island 3 ORF9 protein

X: VSG (variant surface glycoprotein) N-terminal domain

X: Colicin M-related

X: Polymerase cofactor VP35 C-terminal RNA binding domain

X: Phage G1 gp67

X: DNA gyrase subunit B insertion domain

X: Hypothetical protein BT3222 N-terminal domain

X: L-Lys epsilon-oxidase C-terminal domain

X: Middle domain in PB2

X: Orbivirus outer capsid protein VP5

X: Diiron beta-hydroxylase CmlA N-terminal domain

X: CRISPR-associated endonuclease Cas9 C-terminal domain

X: CRISPR-associated endonuclease Cas9 beta-hairpin domain

X: Lid domain of Cas13b

X: CRISPR-associated endonuclease Cas9 wedge domain

X: Phospholipase effector Tle1 C-terminal domain

X: Hypothetical protein lpg2422 after-hydrolase domain

X: C-terminal domain of Ebola nucleoprotein

X: Eukaryal tRNA restriction enzyme PaT

X: N-terminal domain of the pestivirus NS5B protein

X: Monotopic phosphoglycosyl transferase (PGT)-like

X: Insertion domain of minor capsid protein

X: extracellular domain of BK channel beta4 subunit

X: Helical domain of PCIF1/CAPAM

X: C-terminal domain of RNA helicase HrpB

X: RNAi suppressor protein CrPV-1A

X: head domain of ScoMcrA

X: oligomerization domain of PprA

X: SatS C-terminal domain

X: N-terminal domain of SidJ

X: Phage tail fiber assembly protein

X: C-terminal domain of DNA repair helicase RadD

X: VP5 N-terminal domain

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