Annotations: 6KLV

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
E	Cytochrom_B_C	e6klvE2	A: alpha bundles	X: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase) (From Topology)	H: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase) (From Topology)	T: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)	F: Cytochrom_B_C	ECOD (1.6)
E	Cytochrome_B	e6klvE1	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Transmembrane di-heme cytochromes	F: Cytochrome_B	ECOD (1.6)
B	Cytochrom_B_C	e6klvB1	A: alpha bundles	X: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase) (From Topology)	H: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase) (From Topology)	T: a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)	F: Cytochrom_B_C	ECOD (1.6)
B	Cytochrome_B	e6klvB2	A: alpha bundles	X: Transmembrane heme-binding four-helical bundle (From Homology)	H: Transmembrane heme-binding four-helical bundle	T: Transmembrane di-heme cytochromes	F: Cytochrome_B	ECOD (1.6)
A	Rieske_cytochrome_bc1	e6klvA3	A: beta sandwiches	X: ISP domain (From Topology)	H: ISP domain (From Topology)	T: ISP domain	F: Rieske_cytochrome_bc1	ECOD (1.6)
A	Rieske_4	e6klvA1	A: few secondary structure elements	X: Trm112p-like (From Topology)	H: Trm112p-like (From Topology)	T: Trm112p-like	F: Rieske_4	ECOD (1.6)
A	UNK_F_TYPE	e6klvA2	A: extended segments	X: iron-sulfur subunit (ISP) transmembrane anchor (From Topology)	H: iron-sulfur subunit (ISP) transmembrane anchor (From Topology)	T: iron-sulfur subunit (ISP) transmembrane anchor	F: UNK_F_TYPE	ECOD (1.6)
D	Rieske_cytochrome_bc1	e6klvD1	A: beta sandwiches	X: ISP domain (From Topology)	H: ISP domain (From Topology)	T: ISP domain	F: Rieske_cytochrome_bc1	ECOD (1.6)
D	Rieske_4	e6klvD2	A: few secondary structure elements	X: Trm112p-like (From Topology)	H: Trm112p-like (From Topology)	T: Trm112p-like	F: Rieske_4	ECOD (1.6)
D	UNK_F_TYPE	e6klvD3	A: extended segments	X: iron-sulfur subunit (ISP) transmembrane anchor (From Topology)	H: iron-sulfur subunit (ISP) transmembrane anchor (From Topology)	T: iron-sulfur subunit (ISP) transmembrane anchor	F: UNK_F_TYPE	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
E	1.20.810.10	Mainly Alpha	Up-down Bundle	Cytochrome Bc1 Complex	Chain C	CATH (utative)
B	1.20.810.10	Mainly Alpha	Up-down Bundle	Cytochrome Bc1 Complex	Chain C	CATH (utative)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B, E	PF00032	Cytochrome b(C-terminal)/b6/petD (Cytochrom_B_C)	Cytochrome b(C-terminal)/b6/petD		Domain
B, E	PF13631	Cytochrome b(N-terminal)/b6/petB (Cytochrom_B_N_2)	Cytochrome b(N-terminal)/b6/petB		Domain
A, D	PF00355	Rieske [2Fe-2S] domain (Rieske)	Rieske [2Fe-2S] domain	The rieske domain has a [2Fe-2S] centre. Two conserved cysteines coordinate one Fe ion, while the other Fe ion is coordinated by two conserved histidines. In hyperthermophilic archaea there is a SKTPCX(2-3)C motif at the C-terminus. The cysteines in ...	The rieske domain has a [2Fe-2S] centre. Two conserved cysteines coordinate one Fe ion, while the other Fe ion is coordinated by two conserved histidines. In hyperthermophilic archaea there is a SKTPCX(2-3)C motif at the C-terminus. The cysteines in this motif form a disulphide bridge, which stabilises the protein [4].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C, F	Cytochrome c	binding tetrapyrrole binding heme binding electron transfer activity cation binding ion binding metal ion binding small molecule binding	-	cellular anatomical structure membrane
B, E	Cytochrome b	oxidoreductase activity catalytic activity electron transfer activity cation binding ion binding binding metal ion binding small molecule binding	cellular respiration energy derivation by oxidation of organic compounds respiratory electron transport chain electron transport chain metabolic process cellular process generation of precursor metabolites and energy	cellular anatomical structure membrane
A, D	Rieske-I iron sulfur protein	oxidoreductase activity catalytic activity monoatomic cation transmembrane transporter activity proton transmembrane transporter activity primary active transmembrane transporter activity electron transfer activity active monoatomic ion transmembrane transporter activity oxidoreduction-driven active transmembrane transporter activity active transmembrane transporter activity quinol-cytochrome-c reductase activity monoatomic ion transmembrane transporter activity transporter activity transmembrane transporter activity iron-sulfur cluster binding oxidoreductase activity catalytic activity monoatomic cation transmembrane transporter activity proton transmembrane transporter activity primary active transmembrane transporter activity electron transfer activity active monoatomic ion transmembrane transporter activity oxidoreduction-driven active transmembrane transporter activity active transmembrane transporter activity quinol-cytochrome-c reductase activity monoatomic ion transmembrane transporter activity transporter activity transmembrane transporter activity iron-sulfur cluster binding 2 iron, 2 sulfur cluster binding binding metal cluster binding small molecule binding cation binding ion binding metal ion binding	-	cell periphery cellular anatomical structure plasma membrane membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C, F	IPR036909	Cytochrome c-like domain superfamily	Homologous Superfamily
C, F	IPR009056	Cytochrome c-like domain	Domain
B, E	IPR036150	Cytochrome b/b6, C-terminal domain superfamily	Homologous Superfamily
B, E	IPR027387	Cytochrome b/b6-like domain superfamily	Homologous Superfamily
B, E	IPR016174	Di-haem cytochrome, transmembrane	Homologous Superfamily
B, E	IPR005798	Cytochrome b/b6, C-terminal	Domain
B, E	IPR005797	Cytochrome b/b6, N-terminal domain	Domain
A, D	IPR017941	Rieske [2Fe-2S] iron-sulphur domain	Domain
A, D	IPR005805	Rieske iron-sulphur protein, C-terminal	Domain
A, D	IPR036922	Rieske [2Fe-2S] iron-sulphur domain superfamily	Homologous Superfamily
A, D	IPR014349	Rieske iron-sulphur protein	Family
A, D	IPR006317	Ubiquinol-cytochrome c reductase, iron-sulphur subunit	Domain

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
A, B, C, D, E A, B, C, D, E, F	OPM	Transmembrane	Alpha-helical polytopic	Electron transport chain complex III (bc1 and b6f) superfamily	Cytochrome bc1 and b6f complexes

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A, B, C, D, E A, B, C, D, E, F	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A, B, C, D, E A, B, C, D, E, F	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Electron Transport Chain Complexes: Complex III (Cytochrome bc₁)	Cytochrome bc₁ apo structure

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), 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 R01GM157729.