Annotations: 6BTM

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
E	PF13442	e6btmE1	A: alpha arrays	X: Cytochrome c-like	H: Cytochrome c (From Topology)	T: Cytochrome c	F: PF13442	ECOD (1.6)
F	F_UNCLASSIFIED	e6btmF2	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: F_UNCLASSIFIED	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF02085	Class III cytochrome C family (Cytochrom_CIII)	Class III cytochrome C family	-	Domain
B	PF12838	4Fe-4S dicluster domain (Fer4_7)	4Fe-4S dicluster domain	Superfamily includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. Structure of the domain is an alpha-antiparallel beta sandwich. Domain contai ...	Superfamily includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. Structure of the domain is an alpha-antiparallel beta sandwich. Domain contains two 4Fe4S clusters.	Domain
C	PF03916	Polysulphide reductase, NrfD (NrfD)	Polysulphide reductase, NrfD	-	Family
D	PF11821	Alternative complex III, ActD subunit (ActD)	Alternative complex III, ActD subunit	-	Family
E	PF13442	Cytochrome C oxidase, cbb3-type, subunit III (Cytochrome_CBB3)	Cytochrome C oxidase, cbb3-type, subunit III	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Alternative Complex III subunit A	binding organic cyclic compound binding tetrapyrrole binding heme binding electron transfer activity cation binding ion binding metal ion binding small molecule binding	-	membrane cellular anatomical entity
B	Alternative Complex III subunit B	iron-sulfur cluster binding binding 4 iron, 4 sulfur cluster binding metal cluster binding small molecule binding cation binding ion binding metal ion binding	-	-
C	Alternative Complex III subunit C	-	-	cell periphery plasma membrane membrane cellular anatomical entity
D	Alternative Complex III subunit D	-	-	membrane cellular anatomical entity
E	Alternative Complex III subunit E	binding organic cyclic compound binding tetrapyrrole binding heme binding electron transfer activity cation binding ion binding metal ion binding small molecule binding	-	-
F	Alternative Complex III subunit F	-	-	membrane cellular anatomical entity

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR020942	Class III cytochrome C	Domain
A	IPR036280	Multiheme cytochrome superfamily	Homologous Superfamily
A	IPR036909	Cytochrome c-like domain superfamily	Homologous Superfamily
A	IPR009056	Cytochrome c-like domain	Domain
B	IPR017896	4Fe-4S ferredoxin-type, iron-sulphur binding domain	Domain
B	IPR030948	TAT-variant-translocation signal domain	Domain
C	IPR005614	NrfD family	Family
D	IPR021776	Alternative complex III, ActD subunit	Family
E	IPR036909	Cytochrome c-like domain superfamily	Homologous Superfamily
E	IPR009056	Cytochrome c-like domain	Domain

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
A, C, D, E, F	OPM	Transmembrane	Alpha-helical polytopic	Electron transport chain complex II superfamily	Polysulfide reductase

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

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

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

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

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A, C, D, E, F	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Electron Transport Chain Complexes: Complex III (Cytochrome bc₁)	Alternative complex III (ACIII) in SMA nanodiscs

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 R01GM133198.