Structural Classification of Proteins




Class: Alpha and beta proteins (a+b)
- Mainly antiparallel beta sheets (segregated alpha and beta regions)
Lineage:
- Root: scop
- Class: Alpha and beta proteins (a+b) [53931]
Mainly antiparallel beta sheets (segregated alpha and beta regions)
Folds:
- Microbial ribonucleases [53932] (1)
single helix packs against antiparallel beta-sheet
- Microbial ribonucleases [53933] (3)

- Lysozyme-like [53954] (1)
common alpha+beta motif for the active site region
- Lysozyme-like [53955] (7)

- Cysteine proteinases [54000] (1)
consists of one alpha-helix and 4 strands of antiparallel beta-sheet and contains the catalytic triad Cys-His-Asn
- Cysteine proteinases [54001] (16)

the constitute families differ by insertion into and circular permutation of the common catalytic core made of one alpha-helix and 3-strands of beta-sheet
- His-Me finger endonucleases [54059] (1)
core: (alpha)-beta-omega_loop-beta-alpha; embeded in larger different structures
- His-Me finger endonucleases [54060] (6)

common motif contains conserved histidine residue and metal-binding site
- RNase A-like [54075] (1)
contains long curved beta-sheet and 3 helices
- RNase A-like [54076] (1)

can be classified as disulfide-rich
- EndoU-like [142876] (1)
comprises several helices and two three-stranded antiparallel beta-sheets; similar architecture to the RNase A-like fold (scop_cf 54075)
- EndoU-like [142877] (2)

similarity to the RNase A-like superfamily (scop_sf 54076) extends to the active site location and architecture; the two structural cores of the RNase A and EndoU superfamilies are interrelated by a topological permutation - transposition of two pereferial beta-strands, suggesting possible distant homology of the two superfamilies (and their unification in a hyperfamily)
- Prion-like [54097] (1)
beta-alpha-beta-alpha(2); antiparallel beta-ribbon
- Prion-like [54098] (1)

- LysM domain [54105] (1)
beta-alpha(2)-beta; antiparallel strands
- LysM domain [54106] (1)

- Head-to-tail joining protein W, gpW [64209] (1)
alpha-beta(2)-alpha; antiparallel hairpin
- Head-to-tail joining protein W, gpW [64210] (1)

- Hypothetical protein MTH677 [110782] (1)
alpha-beta(2)-alpha; 2 layers a/b; antiparallel beta-hairpin
- Hypothetical protein MTH677 [110783] (1)

- GTF2I-like repeat [117772] (1)
alpha(2)-beta-alpha-beta-alpha; 2 layers: a/b; antiparallel beta-ribbon
- GTF2I-like repeat [117773] (1)

- Urease, gamma-subunit [54110] (1)
alpha(3)-beta(2); antiparallel hairpin
- Urease, gamma-subunit [54111] (1)

- IL8-like [54116] (2)
beta(3)-alpha
- Interleukin 8-like chemokines [54117] (1)

form dimers with different dimerisation modes
- PhtA domain-like [142887] (1)

contains extra N-terminal beta-hairpin, like structurally similar archaeal "histone-like" proteins (scop_fa 54161), but does not adopt its SH3-like barrel fold
- DNA-binding domain [54170] (1)
beta(3)-alpha; 2 layers: alpha/beta
- DNA-binding domain [54171] (4)

- Penicillin-binding protein 2x (pbp-2x), c-terminal domain [54183] (1)
alpha1-beta3; 2 layers: alpha/beta; order 132
- Penicillin-binding protein 2x (pbp-2x), c-terminal domain [54184] (1)

duplication: consists of 2 subdomains of this fold
- Dodecin subunit-like [88797] (5)
beta-alpha-beta(2); 2 layers: alpha/beta; antiparallel beta-sheet: order 132
- Flavin-binding protein dodecin [89807] (1)

- Amyloid beta a4 protein copper binding domain (domain 2) [89811] (1)

- N-terminal, heterodimerisation domain of RBP7 (RpoE) [88798] (1)

- D-lysine 5,6-aminomutase beta subunit KamE, N-terminal domain [117778] (1)

- YbjQ-like [117782] (1)

pentamer, beta/alpha-propeller; additional short beta-strands promote oligomeric assembly
- Ribosomal proteins S24e, L23 and L15e [54188] (1)
beta-(alpha)-beta-alpha-beta(2); 3 layers: alpha/beta/alpha; antiparallel beta-sheet: order 1243
- Ribosomal proteins S24e, L23 and L15e [54189] (3)

- Ribosome binding domain-like [100965] (2)
beta-(2)-alpha(2)-beta(2); 2 layers: beta/alpha; antiparallel beta-sheet: order 1243; topological similarity to the common core of ribosomal proteins L23 and L15e
- Trigger factor ribosome-binding domain [102735] (1)

- Translation initiation factor 2 beta, aIF2beta, N-terminal domain [100966] (1)

- TFB5-like [142896] (1)
beta-alpha-beta(2)-alpha; 2 layers, a/b; antiparallel sheet, order: 132; dimerises in solution (PDB 2jnj) via extended N-terminal strand
- TFB5-like [142897] (1)

- Obg GTP-binding protein C-terminal domain [102740] (1)
beta-(2)-alpha(3)-beta(2); 2 layers: beta/alpha; mixed beta-sheet: order 1234; strands 2 and 3 a parallel to each other
- Obg GTP-binding protein C-terminal domain [102741] (1)

- HIT-like [54196] (2)
alpha-beta(3)-alpha-beta(2); 3 layers: alpha/beta/alpha
- HIT-like [54197] (3)

- Rotavirus NSP2 fragment, C-terminal domain [75347] (1)

- Secretion chaperone-like [69634] (3)
alpha-beta(3)-alpha-beta(2)-alpha; 2 layers: alpha/beta
- Type III secretory system chaperone [69635] (1)

- Arp2/3 complex subunits [69645] (1)

- YjbR-like [142906] (1)

overall similar to the Type III secretory system chaperone subunits; different shape of the beta-sheet
- DNA-binding domain of intron-encoded endonucleases [64495] (1)
beta(2)-alpha(2)-beta; 2 layers; 3-stranded antiparallel beta-sheet, order 213; HTH motif; also includes the extra N-terminal, DNA minor groove-binding helix
- DNA-binding domain of intron-encoded endonucleases [64496] (1)

- MotA C-terminal domain-like [69651] (1)
alpha-beta(4)-alpha-beta(2)-alpha; 2 layers: alpha/beta
- DNA-binding C-terminal domain of the transcription factor MotA [69652] (1)

- YktB/PF0168-like [142912] (1)
alpha-beta(4)-alpha-beta(2)-alpha-beta-alpha; 2 layers, a/b; antiparallel beta-sheet, order: 1234756; half-barrel shape; topological similarity to the MotA C-terminal domain-like fold (scop_cf 69651) and the Secretion chaperone-like fold (scop_cf 69634)
- YktB/PF0168-like [142913] (2)

- Mago nashi protein [89816] (1)
beta(4)-alpha-beta(2)-alpha; 2 layers: alpha/beta; antiparallel beta-sheet, order: 651234
- Mago nashi protein [89817] (1)

- WGR domain-like [142920] (1)
beta(4)-alpha-X-beta; 2 layers, a/b; antiparallel beta-sheet, order 51234; the beta-hairpin insetrion in strand 1 results in the formation of a beta-triangle structure
- WGR domain-like [142921] (1)

- Ribosomal protein S5 domain 2-like [54210] (1)
core: beta(3)-alpha-beta-alpha; 2 layers: alpha/beta; left-handed crossover
- Ribosomal protein S5 domain 2-like [54211] (12)

- beta-Grasp (ubiquitin-like) [54235] (13)
core: beta(2)-alpha-beta(2); mixed beta-sheet 2143
- Ubiquitin-like [54236] (7)

- CAD & PB1 domains [54277] (2)

contain extra helix; similar heterodimerization modes; possibly related to the ubiquitin-like superfamily
- MoaD/ThiS [54285] (3)

possible link between the ubiquitin-like and 2Fe-2S ferredoxin-like superfamilies
- TGS-like [81271] (2)

possibly related to the ubiquitin-like and MoaD/ThiS superfamilies; some similarity to the alpha-L RNA-binding motif
- 2Fe-2S ferredoxin-like [54292] (2)

- Staphylokinase/streptokinase [54328] (1)

- Doublecortin (DC) [89837] (1)

possibly related to the ubiquitin-like superfamily
- Superantigen toxins, C-terminal domain [54334] (1)

- Immunoglobulin-binding domains [54358] (1)

- Translation initiation factor IF3, N-terminal domain [54364] (1)

- Glutamine synthetase, N-terminal domain [54368] (1)

- TmoB-like [110814] (1)

possibly related to the ubiquitin-like and/or 2Fe-2S ferredoxin-like superfamilies
- Nqo1 middle domain-like [142984] (1)

possibly evolved from 2Fe-2S ferredoxins; contains no iron-sulfur cluster
- WWE domain [117838] (1)
beta(2)-alpha-beta(4); antiparallel folded beta-sheet (half-barrel), order 216543
- WWE domain [117839] (1)

- FAD-linked reductases, C-terminal domain [54372] (1)
alpha+beta sandwich
- FAD-linked reductases, C-terminal domain [54373] (7)

N-terminal domain is beta/beta/alpha common fold
- Cystatin-like [54402] (7)
Core: alpha-beta(4); helix packs against coiled antiparallel beta-sheet
- Cystatin/monellin [54403] (5)

has a additional strand at the N-terminus
- Amine oxidase N-terminal region [54416] (1)

- DsbC/DsbG N-terminal domain-like [54423] (1)

- NTF2-like [54427] (13)

has a beta-alpha(2)-beta insertion after the main helix
- Uracil-DNA glycosylase inhibitor protein [54441] (1)

has an additional strand at the C-terminus and a helix inserted after the first strand
- Putative dsDNA mimic [102816] (1)

elaborated with additional structures; some similarity to Uracil-DNA glycosylase (UGI) and Nuclease A (NuiA) inhibitors
- Pre-PUA domain [88802] (4)

this domain is found in association with the PUA domain in the C-terminal region of Archaeosine tRNA-guanine transglycosylase and related stand-alone proteins
- Nuclease A inhibitor (NuiA) [82601] (1)
alpha-beta-alpha-beta-alpha(2)-beta(3); antiparallel beta-sheet; order: 15432
- Nuclease A inhibitor (NuiA) [82602] (1)

some structural similarity to Uracil-DNA glycosylase inhibitor and putative dsDNA mimic HI1450 of the cystatin-like fold
- Colicin D/E5 nuclease domain [102823] (1)
alpha(2)-beta(4)-alpha, 2 layers: alpha/beta, antiparallel beta sheet, meander
- Colicin D/E5 nuclease domain [102824] (2)

- RelE-like [143010] (1)
beta-alpha(2)-beta(4), 2 layers; a/b, antiparallel beta-sheet; order 15432
- RelE-like [143011] (2)

Toxin component of plasmid stabilisation system
- Hypothetical protein SAV1430 [110835] (1)
beta(3)-alpha-beta(2)-alpha; 2 layers, alpha/beta; antiparallel beta-sheet, order: 12543
- Hypothetical protein SAV1430 [110836] (1)

- Ns1 effector domain-like [143020] (1)
beta-X-beta(5)-alpha-beta-alpha; 2 layers: a/b; bifurcated beta-sheet; order 23654[1,7]
- Ns1 effector domain-like [143021] (1)

- YbaB-like [82606] (1)
core: alpha-beta(3)-alpha, 2 layers:alpha/beta, three-stranded antiparallel beta sheet, strand order 123
- YbaB-like [82607] (1)

forms tight dimer of a 3-layer structure: beta/alpha/beta
- Kinetochore globular domain-like [143025] (1)
core: alpha-beta(3)-alpha; variant: alpha-beta(4)-alpha(2)
- Kinetochore globular domain [143026] (2)

swapped heterodimer with the N-terminal helices; Spc24-like subunits have the core fold, whereas Spc25-like subunits have a variant fold
- L35p-like [143033] (1)
core: alpha-beta(3)-alpha; 2layers a/b
- L35p-like [143034] (1)

- Cell division protein ZapA-like [102828] (1)
core: beta(2)-alpha(2), 2 layers: alpha/beta; long C-terminal helix forms dimeric parallel and tetrameric antiparallel coiled coils
- Cell division protein ZapA-like [102829] (1)

- ssDNA-binding transcriptional regulator domain [54446] (1)
helix-swapped dimer of beta(4)-alpha motifs
- ssDNA-binding transcriptional regulator domain [54447] (4)

- Photosystem I subunit PsaD [64233] (1)
beta-BETA(2)-beta-alpha-beta(2); antiparallel sheet: order 2134 packed against helix and BETA-hairpin on the same side; irregular C-terminal tail
- Photosystem I subunit PsaD [64234] (1)

- MHC antigen-recognition domain [54451] (1)
dimeric
- MHC antigen-recognition domain [54452] (1)

- UBC-like [54494] (1)
alpha-beta(4)-alpha(3); core: meander beta-sheet plus one helix 2
- UBC-like [54495] (4)

- SAND domain-like [63762] (1)
core: three short helices packed against a barrel-like beta-sheet; some similarity to the SH3-like fold
- SAND domain-like [63763] (2)

- Coronavirus NSP8-like [143075] (1)
core: alpha-beta(2)-alpha-beta(4)-alpha-beta; bifurcated barrel-like beta-sheet
- Coronavirus NSP8-like [143076] (1)

- ParB/Sulfiredoxin [110848] (1)
beta*-alpha-beta(2)-alpha-beta-alpha; mixed beta sheet forms a partly open barrel: (n*=4, S*=8)
- ParB/Sulfiredoxin [110849] (2)

- BtrG-like [110856] (1)
beta-alpha-beta(4)-alpha-beta(2); contains beta-sheet barrel (n=5, S=8)
- BtrG-like [110857] (1)

- BB1717-like [143080] (1)
complex fold with a bifurcated beta-sheet structure surrounded by helices; contains beta-sheet barrel, closed (n=5, S=8)
- BB1717-like [143081] (1)

- AF0104/ALDC/Ptd012-like [117855] (1)
duplication: consists of two similar beta-alpha-beta(4) motifs
- AF0104/ALDC/Ptd012-like [117856] (3)

characteristic metal ion (zinc)-binding motif in the putative active site
- NSFL1 (p97 ATPase) cofactor p47, SEP domain [102847] (1)
beta(3)-alpha(2)-beta; 2 layers; mixed beta-sheet, order 4123, strands 1 and 4 are parallel to each other
- NSFL1 (p97 ATPase) cofactor p47, SEP domain [102848] (1)

- TTHA1013-like [143099] (1)
beta(3)-alpha-beta; 2 layers; mixed beta-sheet, order 4123, strands 1 and 4 are parallel to each other; topological similarity to the SEP domain fold (scop_cf 102847); dimerises via the long C-terminal strand with the formation of a single beta-sheet
- TTHA1013-like [143100] (1)

- Diaminopimelate epimerase-like [54505] (1)
mixed beta-sheet folds into a barrel (n=8, S=14) around the central helix
- Diaminopimelate epimerase-like [54506] (3)

duplication: consists of two similar domain swapped with C-terminal strands
- GFP-like [54510] (1)
beta-sheet folds into a barrel (n=11, S=14) around the central helix
- GFP-like [54511] (2)

- Tubby C-terminal domain-like [54517] (1)
beta-sheet folds into a barrel (n=12, S=12) around the central helix
- Tubby C-terminal domain-like [54518] (2)

- Pili subunits [54522] (1)
contains very long N-terminal helix, which end is packed against beta-sheet
- Pili subunits [54523] (4)

bacterial filament proteins
- Mitochondrial glycoprotein MAM33-like [54528] (1)
core: beta(7)-alpha(2); N- and C-terminal extensions form a coiled coil subdomain
- Mitochondrial glycoprotein MAM33-like [54529] (1)

- NAP-like [143112] (1)
core: central meander 4-stranded beta-sheet (order: 1234) transversed by a C-terminal helix
- NAP-like [143113] (1)

- Polo-box domain [82614] (1)
beta(6)-alpha; antiparallel beta-sheet, meander
- Polo-box domain [82615] (2)

Serine/threonine protein kinase-associated motif embedded in two distinct folds
- mRNA decapping enzyme DcpS N-terminal domain [102859] (1)
beta(3)-alpha-beta(3)-alpha; 3 layers a/b/a
- mRNA decapping enzyme DcpS N-terminal domain [102860] (1)

forms swapped dimer with two 6-stranded antiparallel beta sheets; order 1236[5][4]
- Inhibitor of vertebrate lysozyme, Ivy [89871] (1)
alpha(2)-beta(5)-alpha(2); 3 layers a/b/a; meander beta-sheet
- Inhibitor of vertebrate lysozyme, Ivy [89872] (1)

- FKBP-like [54533] (3)
core: beta(2)-alpha-beta(2); antiparallel beta-sheet
- FKBP-like [54534] (3)

- Colicin E3 immunity protein [54552] (1)

- Chitinase insertion domain [54556] (1)

- Ribosomal protein S16 [54564] (1)
beta(4)-alpha-beta; 2 layers: alpha/beta; mixed beta-sheet, order: 51234
- Ribosomal protein S16 [54565] (1)

- Ribosomal protein S19 [54569] (1)
alpha-beta-X-beta(2); 2 layers: alpha/beta; mixed beta-sheet, order: 123
- Ribosomal protein S19 [54570] (1)

- YefM-like [143119] (1)
core: beta-alpha(2)-beta(2)-alpha; mixed beta-sheet, order:123, strands 1 and 2 are parallel; forms compact dimer with a single beta-sheet;
- YefM-like [143120] (1)

- Ribosomal protein L31e [54574] (1)
beta-alpha-beta-(alpha)-beta(2); 2 layers: alpha/beta; mixed beta-sheet, order: 1342
- Ribosomal protein L31e [54575] (1)

- Allophycocyanin linker chain (domain) [54579] (1)
beta(2)-alpha-beta; 2 layers: alpha/beta
- Allophycocyanin linker chain (domain) [54580] (1)

- Cdc48 domain 2-like [54584] (1)
beta-alpha-beta(3); 2 layers: alpha/beta
- Cdc48 domain 2-like [54585] (1)

- Glyoxalase/Bleomycin resistance protein/Dihydroxybiphenyl dioxygenase [54592] (1)
beta-alpha-beta(3); 2 layers: alpha/beta
- Glyoxalase/Bleomycin resistance protein/Dihydroxybiphenyl dioxygenase [54593] (10)

- Chromosomal protein MC1 [102874] (1)
beta(2)-alpha-beta(3); 2 layers: alpha/beta
- Chromosomal protein MC1 [102875] (1)

- beta-hairpin-alpha-hairpin repeat [74651] (2)
multiple repeats of beta(2)-alpha(2) motif
- Ankyrin repeat [48403] (1)

repeats organized in elongated structures
- Plakin repeat [75399] (1)

repeats associate forming globular subdomains
- Proguanylin [89889] (1)
beta(2)-alpha(3)-beta; two layers: alpha/beta; antiparallel sheet: order 213
- Proguanylin [89890] (1)

- Bacterial protein-export protein SecB [54610] (1)
beta(4)-alpha(2); two layers: alpha/beta; antiparallel sheet: order 1432
- Bacterial protein-export protein SecB [54611] (1)

- MesJ substrate recognition domain-like [82828] (1)
beta-alpha(2)-beta(3); 2 layers: a/b; antiparallel beta-sheet, order:1432
- MesJ substrate recognition domain-like [82829] (1)

- FYSH domain [89894] (1)
beta(2)-alpha(2)-beta(2)-alpha-beta; two layers: alpha/beta; antiparallel sheet: order 51234
- FYSH domain [89895] (2)

- VSV matrix protein [75403] (1)
beta-alpha(2)-beta(4)-alpha-beta(2); two layers: alpha/beta; bifurcated coiled beta-sheet: order of the first 5 strands: 23154
- VSV matrix protein [75404] (1)

- DNA-binding domain of Mlu1-box binding protein MBP1 [54615] (1)
beta(4)-alpha(2)-beta(2)-alpha; antiparallel sheet: order 123465
- DNA-binding domain of Mlu1-box binding protein MBP1 [54616] (1)

has some topological similarity to the "winged helix" DNA-binding domain, to B1 and B5 domains of PheRS-beta (1PYS CH B) and to methyl-CpG-binding domain
- Heme-binding protein A (HasA) [54620] (1)
beta-alpha-beta(6)-alpha(2); antiparallel sheet: order 165432
- Heme-binding protein A (HasA) [54621] (1)

- Chalcone isomerase [54625] (1)
beta(3)-alpha(2)-beta-alpha(2)-beta3; 2 layers alpha/beta; antiparallel sheet: order 1234567
- Chalcone isomerase [54626] (1)

- Coproporphyrinogen III oxidase [102885] (1)
alpha-beta(6)-alpha(2)-beta-alpha(n); 3 layers alpha/beta/alpha; antiparallel sheet: order 1234567
- Coproporphyrinogen III oxidase [102886] (1)

- Hypothetical protein Ta1206 [102890] (1)
beta(4)-alpha-beta(2)-alpha(2); mixed, predominately antiparallel beta-sheet, order: 123465, strands 4 and 5 are parallel to each other
- Hypothetical protein Ta1206 [102891] (1)

can be divided into an N-terminal, tetramerisation all-beta subdomain and a C-terminal alpha+beta subdomain related by a circular permutation to the Y-family DNA-polymerase 'fingers' subdomain
- CBS-domain [54630] (1)
core: beta-alpha-beta(4); 2 layers: alpha/beta
- CBS-domain [54631] (1)

- Thioesterase/thiol ester dehydrase-isomerase [54636] (1)
core: beta-alpha-beta(4); 2 layers: alpha/beta
- Thioesterase/thiol ester dehydrase-isomerase [54637] (8)

- DLC [54647] (1)
core: beta-alpha(2)-beta-X-beta(2); 2 layers: alpha/beta; antiparallel beta-sheet: order 1342
- DLC [54648] (1)

- CI-2 family of serine protease inhibitors [54653] (1)
alpha+beta sandwich; loop across free side of beta-sheet
- CI-2 family of serine protease inhibitors [54654] (1)

- Integrin beta tail domain [69686] (1)
alpha-beta-loop-beta(3); loop across free side of beta-sheet
- Integrin beta tail domain [69687] (1)

- alpha/beta-Hammerhead [54664] (5)
core: beta-BETA-alpha-beta-BETA-beta-alpha; contains a beta-hammerhead motif similar to that in barrel-sandwich hybrids
- CO dehydrogenase molybdoprotein N-domain-like [54665] (1)

- Nicotinate/Quinolinate PRTase N-terminal domain-like [54675] (2)

- Pyrimidine nucleoside phosphorylase C-terminal domain [54680] (1)

- Ribosomal protein L16p/L10e [54686] (2)

- Molybdopterin synthase subunit MoaE [54690] (1)

- POZ domain [54694] (1)
core: beta(2)-alpha(2)-beta(2)-alpha(2); 2 layers a/b; mixed sheet: 2143
- POZ domain [54695] (2)

- EF-Ts domain-like [54712] (2)
beta(2)-alpha(n)-beta; 2 layers a/b; antiparallel sheet: 123
- Elongation factor Ts (EF-Ts), dimerisation domain [54713] (1)

comprises two structural repeats of this fold
- Band 7/SPFH domain [117892] (1)

beta(2)-alpha(3)-beta
- Fe,Mn superoxide dismutase (SOD), C-terminal domain [54718] (1)
alpha-beta(2)-alpha-beta-alpha(2); 3 strands of antiparallel sheet: 213
- Fe,Mn superoxide dismutase (SOD), C-terminal domain [54719] (1)

- ClpS-like [54735] (1)
beta-alpha(2)-beta-alpha-beta; 2 layers, alpha/beta
- ClpS-like [54736] (2)

- Hypothetical protein MTH1880 [75411] (1)
beta-alpha-beta(2)-alpha(2); 3 layers, alpha/beta/alpha; antiparallel beta-sheet: order 123
- Hypothetical protein MTH1880 [75412] (1)

- Ribosomal L11/L12e N-terminal domain [54746] (1)
beta-alpha(2)-beta(2); 2 layers, alpha/beta; antiparallel beta-sheet: order 123
- Ribosomal L11/L12e N-terminal domain [54747] (1)

- Anti-LPS factor/recA domain [54751] (2)
alpha-beta(3)-alpha(2); 2 layers, alpha/beta
- RecA protein, C-terminal domain [54752] (1)

- Anti-lipopolysaccharide factor [54757] (1)

- Signal recognition particle alu RNA binding heterodimer, SRP9/14 [54761] (1)
(beta)-alpha-beta(3)-alpha; 2 layers, alpha/beta
- Signal recognition particle alu RNA binding heterodimer, SRP9/14 [54762] (1)

- dsRBD-like [54767] (5)
alpha-beta(3)-alpha; 2 layers: alpha/beta
- dsRNA-binding domain-like [54768] (3)

- Porphobilinogen deaminase (hydroxymethylbilane synthase), C-terminal domain [54782] (1)

- YcfA/nrd intein domain [54786] (2)

- Peptidyl-tRNA hydrolase domain-like [110916] (1)

- Rv2632c-like [143212] (1)

lacks the N-terminal helix; dimerises via the N-terminal strand and the C-terminal helix with the formation of a single beta-sheet wrapped around an antiparallel coiled coil
- 2-isopropylmalate synthase LeuA, allosteric (dimerisation) domain [110920] (1)
duplication: consists of two beta(3)-alpha repeats; 3 layers, beta/alpha/beta
- 2-isopropylmalate synthase LeuA, allosteric (dimerisation) domain [110921] (1)

- SRP19 [69694] (1)
beta-alpha-beta(2)-alpha; 2 layers: alpha/beta
- SRP19 [69695] (1)

- SufE/NifU [82648] (1)
alpha(2)-beta(3)-alpha(3); 2 layers alpha/beta, 3-stranded antiparallel beta-sheet; order 123
- SufE/NifU [82649] (3)

iron-sulfur cluster assembly proteins
- DNA-binding protein Tfx [89914] (1)
alpha(3)-beta-alpha(2)-beta(2); 2 layers alpha/beta, 3-stranded antiparallel beta-sheet; order 123
- DNA-binding protein Tfx [89915] (1)

- Eukaryotic type KH-domain (KH-domain type I) [54790] (1)
beta-alpha(2)-beta(2)-alpha; 2 layers: alpha/beta
- Eukaryotic type KH-domain (KH-domain type I) [54791] (1)

Prokaryotic and eukaryotic domains share a KH-motif but have different topologies
- Alpha-lytic protease prodomain-like [54805] (8)
core: alpha-beta(2)-(alpha)-beta; 2 layers: alpha/beta
- Alpha-lytic protease prodomain [54806] (1)

- GMP synthetase C-terminal dimerisation domain [54810] (1)

- Prokaryotic type KH domain (KH-domain type II) [54814] (1)

Prokaryotic and eukaryotic domains share a KH-motif but have different topologies
- Probable GTPase Der, C-terminal domain [82653] (1)

possible distant relative of the Era C-terminal domain lacking the KH motif
- Ribosome-binding factor A, RbfA [89919] (1)

possible distant homologue of the type I KH domain lacking the KH motif
- YhbC-like, N-terminal domain [75420] (1)

- BolA-like [82657] (1)

- Fe-S cluster assembly (FSCA) domain-like [117916] (2)

similar putative active site with a conserved cysteine residue
- Nucleotidyltransferase [81302] (1)
core: alpha-beta-turn-beta-X-beta-(alpha); mixed beta-sheet, order of core strands: 123
- Nucleotidyltransferase [81301] (11)

- Nqo5-like [143242] (1)
core: alpha-beta(2)-alpha-beta(3); 2 layers, a/b; mixed beta-sheet, order 12534, strands 2 and 5 are parallel
- Nqo5-like [143243] (1)

- Ribosomal protein S3 C-terminal domain [54820] (1)
alpha(2)-beta(4); 2 layers: alpha/beta; antiparallel beta-sheet: order 2143
- Ribosomal protein S3 C-terminal domain [54821] (1)

- Transcription factor NusA, N-terminal domain [69704] (1)
alpha-beta(3)-alpha-beta-alpha; bifurcated coiled beta-sheet
- Transcription factor NusA, N-terminal domain [69705] (1)

- Enolase N-terminal domain-like [54825] (1)
beta(3)-alpha(3); meander and up-and-down bundle
- Enolase N-terminal domain-like [54826] (1)

- Ribosomal protein L22 [54842] (1)
beta-alpha(3)-beta(2); 2 layers: alpha/beta; related to the enolase/MLE N-domain fold by a circular permutation
- Ribosomal protein L22 [54843] (1)

some topological similarity to prokaryotic ribosomal protein L17
- Prokaryotic ribosomal protein L17 [64262] (1)
alpha-beta-alpha(3)-beta(2); 2 layers: alpha/beta;
- Prokaryotic ribosomal protein L17 [64263] (1)

some topological similarity to ribosomal protein L22
- GroEL-intermediate domain like [54848] (1)
3-helical bundle packed against 3-stranded mixed beta-sheet
- GroEL-intermediate domain like [54849] (2)

- PX domain [64267] (1)
beta(3)-alpha(4); meander beta-sheet packed against array of helices; contains Pro-rich stretch
- PX domain [64268] (1)

- DsrC, the gamma subunit of dissimilatory sulfite reductase [69720] (1)
beta(3)-alpha(5); meander beta-sheet packed against array of helices
- DsrC, the gamma subunit of dissimilatory sulfite reductase [69721] (1)

- DNA damage-inducible protein DinI [54856] (1)
beta-alpha-beta(2)-alpha; 2 layers: alpha/beta; mixed sheet 213; crossing loops
- DNA damage-inducible protein DinI [54857] (1)

- HSP90 C-terminal domain [110941] (1)
alpha-beta(3)-alpha(3); 2 layers, a/b; mixed beta-sheet, order:132; crossing loops
- HSP90 C-terminal domain [110942] (1)

- Ferredoxin-like [54861] (55)
alpha+beta sandwich with antiparallel beta-sheet; (beta-alpha-beta)x2
- 4Fe-4S ferredoxins [54862] (6)

- Aspartate carbamoyltransferase, Regulatory-chain, N-terminal domain [54893] (1)

- Protease propeptides/inhibitors [54897] (3)

- Dimeric alpha+beta barrel [54909] (17)

dimerizes through the beta-sheet; forms beta-sheet barrel, closed (n=8, S=12); dimers may assemble in higher oligomers
- GlnB-like [54913] (4)

form timeric structures with the orthogonally packed beta-sheets
- SEA domain [82671] (1)

- Nucleoside diphosphate kinase, NDK [54919] (1)

- RNA-binding domain, RBD [54928] (4)

- Viral DNA-binding domain [54957] (1)

- RuBisCO, large subunit, small (N-terminal) domain [54966] (1)

C-terminal domain is beta/alpha barrel
- Acylphosphatase/BLUF domain-like [54975] (2)

- EF-G C-terminal domain-like [54980] (3)

- eEF-1beta-like [54984] (1)

- eEF1-gamma domain [89942] (1)

elaborated with additional structures
- Anticodon-binding domain of PheRS [54991] (1)

- Ribosomal protein S6 [54995] (1)

- Ribosomal protein S10 [54999] (1)

- N-utilization substance G protein NusG, N-terminal domain [82679] (1)

- PAP/Archaeal CCA-adding enzyme, C-terminal domain [55003] (2)

- HMA, heavy metal-associated domain [55008] (1)

- Urease metallochaperone UreE, C-terminal domain [69737] (1)

- ACT-like [55021] (12)

regulatory domain linked to a wide range of metabolic enzymes
- Bacterial exopeptidase dimerisation domain [55031] (1)

- NAD-binding domain of HMG-CoA reductase [55035] (1)

- Molybdenum cofactor biosynthesis protein C, MoaC [55040] (1)

- TRADD, N-terminal domain [55044] (1)

- Probable ACP-binding domain of malonyl-CoA ACP transacylase [55048] (1)

- CheY-binding domain of CheA [55052] (1)

- D-ribose-5-phosphate isomerase (RpiA), lid domain [75445] (1)

- Killer toxin KP6 alpha-subunit [55056] (1)

- Hypothetical protein VC0424 [89946] (1)

- Hypothetical protein TT1725 [103007] (1)

- Mechanosensitive channel protein MscS (YggB), C-terminal domain [82689] (1)

the last strand of the fold is flipped away and involved in oligomerisation
- GHMP Kinase, C-terminal domain [55060] (7)

common fold is elaborated with additional secondary structures
- Translational regulator protein regA [55064] (1)

common fold is elaborated with additional secondary structures
- Peptide methionine sulfoxide reductase [55068] (1)

common fold is elaborated with additional secondary structures