4KX6

Plasticity of the quinone-binding site of the complex II homolog quinol:fumarate reductase

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B	d4kx6b2	All alpha proteins	Globin-like	alpha-helical ferredoxin	Fumarate reductase/Succinate dehydogenase iron-sulfur protein, C-terminal domain	Fumarate reductase	(Escherichia coli BW2952 ) [TaxId: 595496 ],	SCOPe (2.08)
B	d4kx6b1	Alpha and beta proteins (a+b)	beta-Grasp (ubiquitin-like)	2Fe-2S ferredoxin-like	2Fe-2S ferredoxin domains from multidomain proteins	Fumarate reductase iron-sulfur protein, N-terminal domain	(Escherichia coli BW2952 ) [TaxId: 595496 ],	SCOPe (2.08)
F [auth N]	d4kx6n2	All alpha proteins	Globin-like	alpha-helical ferredoxin	Fumarate reductase/Succinate dehydogenase iron-sulfur protein, C-terminal domain	Fumarate reductase	(Escherichia coli BW2952 ) [TaxId: 595496 ],	SCOPe (2.08)
F [auth N]	d4kx6n1	Alpha and beta proteins (a+b)	beta-Grasp (ubiquitin-like)	2Fe-2S ferredoxin-like	2Fe-2S ferredoxin domains from multidomain proteins	Fumarate reductase iron-sulfur protein, N-terminal domain	(Escherichia coli BW2952 ) [TaxId: 595496 ],	SCOPe (2.08)
C	d4kx6c_	Membrane and cell surface proteins and peptides	Heme-binding four-helical bundle	Fumarate reductase respiratory complex transmembrane subunits	Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD)	Fumarate reductase subunit FrdC	(Escherichia coli DH1 ) [TaxId: 536056 ],	SCOPe (2.08)
G [auth O]	d4kx6o_	Membrane and cell surface proteins and peptides	Heme-binding four-helical bundle	Fumarate reductase respiratory complex transmembrane subunits	Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD)	Fumarate reductase subunit FrdC	(Escherichia coli DH1 ) [TaxId: 536056 ],	SCOPe (2.08)
D	d4kx6d_	Membrane and cell surface proteins and peptides	Heme-binding four-helical bundle	Fumarate reductase respiratory complex transmembrane subunits	Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD)	Fumarate reductase subunit FrdD	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)
H [auth P]	d4kx6p_	Membrane and cell surface proteins and peptides	Heme-binding four-helical bundle	Fumarate reductase respiratory complex transmembrane subunits	Succinate dehydrogenase/Fumarate reductase transmembrane subunits (SdhC/FrdC and SdhD/FrdD)	Fumarate reductase subunit FrdD	(Escherichia coli K-12 ) [TaxId: 83333 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	L-aspartate oxidase C-terminal domain-like	8056077	3000021	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Succinate dehydrogenase/fumarate reductase domain-like	8056076	3000054	SCOP2B (2022-06-29)
E [auth M]	SCOP2B Superfamily	Succinate dehydrogenase/fumarate reductase domain-like	8056076	3000054	SCOP2B (2022-06-29)
E [auth M]	SCOP2B Superfamily	L-aspartate oxidase C-terminal domain-like	8056077	3000021	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	Fumarate reductase respiratory complex transmembrane subunits	8040223	3000518	SCOP2B (2022-06-29)
H [auth P]	SCOP2B Superfamily	Fumarate reductase respiratory complex transmembrane subunits	8040223	3000518	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	PF02910	e4kx6A4	A: alpha bundles	X: Spectrin repeat-like	H: Succinate dehydrogenase/fumarate reductase flavoprotein C-terminal domain (From Topology)	T: Succinate dehydrogenase/fumarate reductase flavoprotein C-terminal domain	F: PF02910	ECOD (1.6)
A	PF00890	e4kx6A2	A: a+b complex topology	X: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain (From Topology)	H: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain (From Topology)	T: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain	F: PF00890	ECOD (1.6)
A	PF00890	e4kx6A3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: PF00890	ECOD (1.6)
E [auth M]	PF02910	e4kx6M4	A: alpha bundles	X: Spectrin repeat-like	H: Succinate dehydrogenase/fumarate reductase flavoprotein C-terminal domain (From Topology)	T: Succinate dehydrogenase/fumarate reductase flavoprotein C-terminal domain	F: PF02910	ECOD (1.6)
E [auth M]	PF00890	e4kx6M2	A: a+b complex topology	X: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain (From Topology)	H: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain (From Topology)	T: Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain	F: PF00890	ECOD (1.6)
E [auth M]	PF00890	e4kx6M3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: FAD/NAD(P)-binding domain	F: PF00890	ECOD (1.6)
B	PF13237	e4kx6B1	A: alpha arrays	X: alpha-helical ferredoxin-like	H: alpha-helical ferredoxin (From Topology)	T: alpha-helical ferredoxin	F: PF13237	ECOD (1.6)
B	PF13085	e4kx6B2	A: a+b two layers	X: beta-Grasp	H: Ubiquitin-related	T: Ubiquitin-like	F: PF13085	ECOD (1.6)
F [auth N]	PF13237	e4kx6N1	A: alpha arrays	X: alpha-helical ferredoxin-like	H: alpha-helical ferredoxin (From Topology)	T: alpha-helical ferredoxin	F: PF13237	ECOD (1.6)
F [auth N]	PF13085	e4kx6N2	A: a+b two layers	X: beta-Grasp	H: Ubiquitin-related	T: Ubiquitin-like	F: PF13085	ECOD (1.6)
C	PF02300	e4kx6C1	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Fumarate reductase respiratory complex transmembrane subunits	F: PF02300	ECOD (1.6)
G [auth O]	PF02300	e4kx6O1	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Fumarate reductase respiratory complex transmembrane subunits	F: PF02300	ECOD (1.6)
D	PF02313	e4kx6D1	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Fumarate reductase respiratory complex transmembrane subunits	F: PF02313	ECOD (1.6)
H [auth P]	PF02313	e4kx6P1	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Fumarate reductase respiratory complex transmembrane subunits	F: PF02313	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.50.50.60	Alpha Beta	3-Layer(bba) Sandwich	FAD/NAD(P)-binding domain	FAD/NAD(P)-binding domain	CATH (4.3.0)
A	3.90.700.10	Alpha Beta	Alpha-Beta Complex	Flavocytochrome C3	Chain A, domain 1	CATH (4.3.0)
A	1.20.58.100	Mainly Alpha	Up-down Bundle	Methane Monooxygenase Hydroxylase	Chain G, domain 1	CATH (4.3.0)
A	4.10.80.40	Few Secondary Structures	Irregular	Rhinovirus 14, subunit 4	succinate dehydrogenase protein domain	CATH (4.3.0)
E [auth M]	3.50.50.60	Alpha Beta	3-Layer(bba) Sandwich	FAD/NAD(P)-binding domain	FAD/NAD(P)-binding domain	CATH (4.3.0)
E [auth M]	3.90.700.10	Alpha Beta	Alpha-Beta Complex	Flavocytochrome C3	Chain A, domain 1	CATH (4.3.0)
E [auth M]	1.20.58.100	Mainly Alpha	Up-down Bundle	Methane Monooxygenase Hydroxylase	Chain G, domain 1	CATH (4.3.0)
E [auth M]	4.10.80.40	Few Secondary Structures	Irregular	Rhinovirus 14, subunit 4	succinate dehydrogenase protein domain	CATH (4.3.0)
B	3.10.20.30	Alpha Beta	Roll	Ubiquitin-like (UB roll)	Beta-grasp domain	CATH (4.3.0)
B	1.10.1060.10	Mainly Alpha	Orthogonal Bundle	Fumarate Reductase Iron-sulfur Protein	Chain B, domain 2	CATH (4.3.0)
F [auth N]	3.10.20.30	Alpha Beta	Roll	Ubiquitin-like (UB roll)	Beta-grasp domain	CATH (4.3.0)
F [auth N]	1.10.1060.10	Mainly Alpha	Orthogonal Bundle	Fumarate Reductase Iron-sulfur Protein	Chain B, domain 2	CATH (4.3.0)
C	1.20.1300.10	Mainly Alpha	Up-down Bundle	3 helical TM bundles of succinate and fumarate reductases	Fumarate reductase/succinate dehydrogenase, transmembrane subunit	CATH (4.3.0)
G [auth O]	1.20.1300.10	Mainly Alpha	Up-down Bundle	3 helical TM bundles of succinate and fumarate reductases	Fumarate reductase/succinate dehydrogenase, transmembrane subunit	CATH (4.3.0)
D	1.20.1300.10	Mainly Alpha	Up-down Bundle	3 helical TM bundles of succinate and fumarate reductases	Fumarate reductase/succinate dehydrogenase, transmembrane subunit	CATH (4.3.0)
H [auth P]	1.20.1300.10	Mainly Alpha	Up-down Bundle	3 helical TM bundles of succinate and fumarate reductases	Fumarate reductase/succinate dehydrogenase, transmembrane subunit	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, E [auth M]	PF02910	Fumarate reductase flavoprotein C-term (Succ_DH_flav_C)	Fumarate reductase flavoprotein C-term	This family contains fumarate reductases, succinate dehydrogenases and L-aspartate oxidases.	Domain
A, E [auth M]	PF00890	FAD binding domain (FAD_binding_2)	FAD binding domain	-	Family
D, H [auth P]	PF02313	Fumarate reductase subunit D (Fumarate_red_D)	Fumarate reductase subunit D	Fumarate reductase is a membrane-bound flavoenzyme consisting of four subunits, A-B. A and B comprise the membrane-extrinsic catalytic domain and C and D link the catalytic centres to the electron-transport chain. This family consists of the 13kD hy ...	Fumarate reductase is a membrane-bound flavoenzyme consisting of four subunits, A-B. A and B comprise the membrane-extrinsic catalytic domain and C and D link the catalytic centres to the electron-transport chain. This family consists of the 13kD hydrophobic subunit D.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, E [auth M]	Fumarate reductase flavoprotein subunit	oxidoreductase activity succinate dehydrogenase activity oxidoreductase activity, acting on the CH-CH group of donors catalytic activity FAD binding flavin adenine dinucleotide binding binding nucleoside phosphate binding ion binding organic cyclic compound binding anion binding nucleotide binding heterocyclic compound binding small molecule binding oxidoreductase activity succinate dehydrogenase activity oxidoreductase activity, acting on the CH-CH group of donors catalytic activity FAD binding flavin adenine dinucleotide binding binding nucleoside phosphate binding ion binding organic cyclic compound binding anion binding nucleotide binding heterocyclic compound binding small molecule binding electron transfer activity	cellular response to stimulus cellular response to stress response to stimulus DNA damage response response to stress cellular process anaerobic electron transport chain cellular respiration energy derivation by oxidation of organic compounds cellular metabolic process respiratory electron transport chain electron transport chain metabolic process generation of precursor metabolites and energy cellular response to stimulus cellular response to stress response to stimulus DNA damage response response to stress cellular process anaerobic electron transport chain cellular respiration energy derivation by oxidation of organic compounds cellular metabolic process respiratory electron transport chain electron transport chain metabolic process generation of precursor metabolites and energy anaerobic respiration fermentation organelle assembly cell projection organization non-membrane-bounded organelle assembly bacterial-type flagellum assembly cellular component biogenesis cellular component organization bacterial-type flagellum organization organelle organization cellular component assembly cellular component organization or biogenesis cell projection assembly	respiratory chain complex protein-containing complex catalytic complex plasma membrane protein complex membrane plasma membrane plasma membrane respirasome membrane protein complex cellular anatomical entity cell periphery fumarate reductase complex plasma membrane respiratory chain complex II plasma membrane fumarate reductase complex respiratory chain complex II respiratory chain complex protein-containing complex catalytic complex plasma membrane protein complex membrane plasma membrane plasma membrane respirasome membrane protein complex cellular anatomical entity cell periphery fumarate reductase complex plasma membrane respiratory chain complex II plasma membrane fumarate reductase complex respiratory chain complex II respirasome intracellular anatomical structure cytoplasm cytosol
B, F [auth N]	Fumarate reductase (Anaerobic), Fe-S subunit	-	-	-
C, G [auth O]	Fumarate reductase subunit C	-	-	-
D, H [auth P]	Fumarate reductase subunit D	-	organelle assembly cell projection organization non-membrane-bounded organelle assembly bacterial-type flagellum assembly cellular component biogenesis cellular component organization bacterial-type flagellum organization organelle organization cellular component assembly cellular process cellular component organization or biogenesis cell projection assembly anaerobic electron transport chain cellular respiration organelle assembly cell projection organization non-membrane-bounded organelle assembly bacterial-type flagellum assembly cellular component biogenesis cellular component organization bacterial-type flagellum organization organelle organization cellular component assembly cellular process cellular component organization or biogenesis cell projection assembly anaerobic electron transport chain cellular respiration energy derivation by oxidation of organic compounds cellular metabolic process respiratory electron transport chain electron transport chain metabolic process generation of precursor metabolites and energy anaerobic respiration organic substance metabolic process oxoacid metabolic process dicarboxylic acid metabolic process carboxylic acid metabolic process small molecule metabolic process fumarate metabolic process organic acid metabolic process fermentation	cell periphery plasma membrane membrane cellular anatomical entity respiratory chain complex protein-containing complex catalytic complex plasma membrane protein complex plasma membrane respirasome membrane protein complex fumarate reductase complex plasma membrane respiratory chain complex II plasma membrane fumarate reductase complex respiratory chain complex II cell periphery plasma membrane membrane cellular anatomical entity respiratory chain complex protein-containing complex catalytic complex plasma membrane protein complex plasma membrane respirasome membrane protein complex fumarate reductase complex plasma membrane respiratory chain complex II plasma membrane fumarate reductase complex respiratory chain complex II respirasome

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, E [auth M]	IPR015939	Fumarate reductase/succinate dehydrogenase flavoprotein-like, C-terminal	Domain
A, E [auth M]	IPR003952	Fumarate reductase/succinate dehydrogenase, FAD-binding site	Binding Site
A, E [auth M]	IPR037099	Fumarate reductase/succinate dehydrogenase flavoprotein-like, C-terminal domain superfamily	Homologous Superfamily
A, E [auth M]	IPR036188	FAD/NAD(P)-binding domain superfamily	Homologous Superfamily
A, E [auth M]	IPR003953	FAD-dependent oxidoreductase 2, FAD binding domain	Domain
A, E [auth M]	IPR030664	FAD-dependent oxidoreductase SdhA/FrdA/AprA	Family
A, E [auth M]	IPR005884	Fumarate reductase, flavoprotein subunit	Family
A, E [auth M]	IPR027477	Succinate dehydrogenase/fumarate reductase flavoprotein, catalytic domain superfamily	Homologous Superfamily
A, E [auth M]	IPR014006	Succinate dehydrogenase/fumarate reductase, flavoprotein subunit	Family
D, H [auth P]	IPR034804	Fumarate reductase/succinate dehydrogenase, transmembrane subunit	Homologous Superfamily
D, H [auth P]	IPR003418	Fumarate reductase, subunit D	Family

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A, D, E [auth M], H [auth P]	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A, D, E [auth M], H [auth P]	MemProtMD	Annotated as membrane protein by MemProtMD

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.