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




Representatives:
e2d00A1[A:6-109]
nonrep
Image
Pymol
Jmol Links:
PDB,
SCOP,
CATH, PubMed,
DOI
V-type ATP synthase subunit F ; ligands: CA ; X-RAY DIFFRACTION 2.2Å
swap
e7uzfL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e7uzgL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e7uzhL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e7uziL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e7uzjL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e7uzkL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
; ELECTRON MICROSCOPY
e2d00D1[D:6-109] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ligands: CA ; X-RAY DIFFRACTION 2.2Å
e2d00B1[B:6-109] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ligands: CA ; X-RAY DIFFRACTION 2.2Å
e2d00F1[F:6-109] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; X-RAY DIFFRACTION 2.2Å
e2d00C1[C:6-109] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ligands: CA ; X-RAY DIFFRACTION 2.2Å
e2d00E1[E:6-109] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ligands: CA ; X-RAY DIFFRACTION 2.2Å
e2i4rB1[B:4-79] Image Pymol Jmol Links: PDB, SCOP, CATH
V-TYPE ATP SYNTHASE SUBUNIT F ; X-RAY DIFFRACTION 2.8Å
e3a5cH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE ATP SYNTHASE SUBUNIT F ; X-RAY DIFFRACTION 4.51Å
e3aonB1[B:1-101] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE SODIUM ATPASE SUBUNIT G ; ligands: NO3 ; X-RAY DIFFRACTION 2.0Å
e3vr4H1[H:2-103] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE SODIUM ATPASE SUBUNIT G ; X-RAY DIFFRACTION 2.17Å
e3vr5H1[H:2-101] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit G ; X-RAY DIFFRACTION 3.90Å
e2qaiA1[A:1-97] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type ATP synthase subunit F ; X-RAY DIFFRACTION 2.40Å
e3j0jH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e4ix9B1[B:2-94] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ligands: GOL,TRS ; X-RAY DIFFRACTION 2.33Å
e2qaiB1[B:1-99] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type ATP synthase subunit F ; X-RAY DIFFRACTION 2.40Å
e3a5cP1[P:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE ATP SYNTHASE SUBUNIT F ; X-RAY DIFFRACTION 4.51Å
e3a5dH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE ATP SYNTHASE SUBUNIT F ; X-RAY DIFFRACTION 4.8Å
e3a5dP1[P:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-TYPE ATP SYNTHASE SUBUNIT F ; X-RAY DIFFRACTION 4.8Å
e3w3aH1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; X-RAY DIFFRACTION 3.9Å
e3w3aP1[P:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; X-RAY DIFFRACTION 3.9Å
e2ov6A2[A:1-78] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; SOLUTION NMR
e4ix9D2[D:5-94] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ligands: TRS ; X-RAY DIFFRACTION 2.33Å
e4ix9A2[A:3-94] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ligands: TRS ; X-RAY DIFFRACTION 2.33Å
e4ix9C2[C:3-94] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ligands: GOL ; X-RAY DIFFRACTION 2.33Å
e3vr6H2[H:2-103] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit G ; X-RAY DIFFRACTION 2.68Å
e4rndB1[B:1-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ligands: GOL ; X-RAY DIFFRACTION 3.18Å
e4rndD1[D:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; X-RAY DIFFRACTION 3.18Å
e3j9tN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e3j9uN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e3j9vN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e5garL1[L:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5gasL1[L:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5d80o1[o:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; X-RAY DIFFRACTION 6.010Å
e5d80O1[O:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; X-RAY DIFFRACTION 6.010Å
e5knbH1[H:4-98] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit NtpG (F) ; X-RAY DIFFRACTION 3.2510Å
e5kncH1[H:2-103] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit NtpG (F) ; X-RAY DIFFRACTION 3.0150Å
e5kndH1[H:2-103] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit NtpG (F) ; X-RAY DIFFRACTION 2.888Å
e5tsjL1[L:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5vozN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e5voxN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e5voyN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e5y5xH1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5y5yH1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5y5zH1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e5y60H1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6o7vN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6o7wN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6o7xN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6qumH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6r0wH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6r0yH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6r0zH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6r10H1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6vq6L1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6vq7L1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6vq8L1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6vqcL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6vqgL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6vqhL1[L:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6xbwL1[L:5-107] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6ly8H1[H:1-100] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e6xbyL1[L:6-106] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6wlzN1[N:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6wm2N1[N:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6wm3N1[N:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e6wm4N1[N:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7khrL1[L:5-107] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7fdaN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7fdbN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7fdcN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7fdeN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7vw7H1[H:2-102] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type sodium ATPase subunit NtpG (F) ; X-RAY DIFFRACTION 3.818Å
e7vaiH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vajH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vakH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7valH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vamH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vanH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vaoH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vapH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vaqH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7varH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vasH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vatH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vauH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vavH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vawH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vaxH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vayH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7vb0H1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e7tmmN1[N:2-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmoN1[N:2-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmpN1[N:2-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmqN1[N:2-112] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmrN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmsN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7tmtN1[N:2-116] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7uw9N1[N:12-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7uwaN1[N:12-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7uwbN1[N:12-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7uwcN1[N:12-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7uwdN1[N:12-118] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7u4tN1[N:4-113] Image Pymol Jmol Links: PDB, SCOP, CATH
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7u8oL1[L:5-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7u8pL1[L:5-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7u8qL1[L:5-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7u8rL1[L:5-113] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e7unfF1[F:4-111] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e8gxuH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e8gxwH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e8gxxH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e8gxyH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e8gxzH1[H:1-104] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type ATP synthase subunit F ; ELECTRON MICROSCOPY
e8easF1[F:3-117] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
e8eatF1[F:3-117] Image Pymol Jmol Links: PDB, SCOP, CATH, PubMed, DOI
V-type proton ATPase subunit F ; ELECTRON MICROSCOPY
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