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
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
X: Flavodoxin-like
H: Class I glutamine amidotransferase-like
T: Chelatase-like
F: Oxidored_nitro
Representatives:
e1m1nA1[A:4-210]
nonrep
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Nitrogenase molybdenum-iron protein alpha chain ; ligands: CFN,CLF,HCA ; X-RAY DIFFRACTION 1.16Å
e1m1nA2[A:211-331]
nonrep
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Pymol
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Nitrogenase molybdenum-iron protein alpha chain ; ligands: CFN ; X-RAY DIFFRACTION 1.16Å
e1m1nA3[A:332-480]
nonrep
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Pymol
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Nitrogenase molybdenum-iron protein alpha chain ; ligands: CFN,HCA ; X-RAY DIFFRACTION 1.16Å
e1m1nB2[B:214-349]
nonrep
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Pymol
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Nitrogenase molybdenum-iron protein beta chain ; X-RAY DIFFRACTION 1.16Å
e1m1nB3[B:350-523]
nonrep
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Pymol
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Nitrogenase molybdenum-iron protein beta chain ; ligands: CA ; X-RAY DIFFRACTION 1.16Å
e5n6yA1[A:2-191]
nonrep
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Nitrogenase vanadium-iron protein alpha chain ; ligands: 8P8,CLF,HCA ; X-RAY DIFFRACTION 1.35Å
e5n6yA2[A:192-314]
nonrep
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Pymol
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Nitrogenase vanadium-iron protein alpha chain ; ligands: 8P8 ; X-RAY DIFFRACTION 1.35Å
e5n6yA3[A:315-474]
nonrep
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Nitrogenase vanadium-iron protein alpha chain ; ligands: 8P8,CO3,HCA ; X-RAY DIFFRACTION 1.35Å
e2ynmD2[D:1-148]
nonrep
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LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE SUBUNIT B ; ligands: 1PE,GOL,K,PMR,SF4 ; X-RAY DIFFRACTION 2.1Å
e2ynmD3[D:158-275]
nonrep
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LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE SUBUNIT B ; ligands: EPE ; X-RAY DIFFRACTION 2.1Å
e2ynmD4[D:276-451]
nonrep
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LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE SUBUNIT B ; ligands: EPE,GOL,PMR ; X-RAY DIFFRACTION 2.1Å
e1mioA1[A:2-201]
nonrep
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NITROGENASE MOLYBDENUM IRON PROTEIN (ALPHA CHAIN) ; ligands: CFM,CLP,HCA ; X-RAY DIFFRACTION
e1mioA2[A:202-321]
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NITROGENASE MOLYBDENUM IRON PROTEIN (ALPHA CHAIN) ; ligands: CFM ; X-RAY DIFFRACTION
e1mioA3[A:322-526]
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NITROGENASE MOLYBDENUM IRON PROTEIN (ALPHA CHAIN) ; ligands: CFM,HCA ; X-RAY DIFFRACTION
e1mioB1[B:2-163]
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NITROGENASE MOLYBDENUM IRON PROTEIN (BETA CHAIN) ; ligands: CA,CLP ; X-RAY DIFFRACTION
F: Unmapped domains
Pseudo group of domains that do not map to PFam family profiles. Domains inside should not be considered as in one family.
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