Annotations: 4L3X

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Di-heme elbow motif	8003694	3000145	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Di-heme elbow motif	8003695	3000145	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Di-heme elbow motif	8003696	3000145	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	HAO C-terminal domain-like	8056473	3002349	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Di-heme elbow motif	8003695	3000145	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	HAO C-terminal domain-like	8056473	3002349	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Di-heme elbow motif	8003696	3000145	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Di-heme elbow motif	8003694	3000145	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	Hormone_recep	e4l3xA1	A: alpha bundles	X: Outer membrane meander beta-barrels	H: Porins	T: Porin	F: Hormone_recep	ECOD (develop294)
B	Hormone_recep	e4l3xB1	A: alpha bundles	X: Outer membrane meander beta-barrels	H: Porins	T: Porin	F: Hormone_recep	ECOD (develop294)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.287.3080	Mainly Alpha	Orthogonal Bundle	Helix Hairpins		CATH (4.3.0)
A	1.10.1130.10	Mainly Alpha	Orthogonal Bundle	Flavocytochrome C3	Chain A, domain 2	CATH (4.3.0)
A	1.20.140.10	Mainly Alpha	Up-down Bundle	Butyryl-CoA Dehydrogenase, subunit A	domain 3	CATH (4.3.0)
B	1.10.287.3080	Mainly Alpha	Orthogonal Bundle	Helix Hairpins		CATH (4.3.0)
B	1.10.1130.10	Mainly Alpha	Orthogonal Bundle	Flavocytochrome C3	Chain A, domain 2	CATH (4.3.0)
B	1.20.140.10	Mainly Alpha	Up-down Bundle	Butyryl-CoA Dehydrogenase, subunit A	domain 3	CATH (4.3.0)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	Eight-heme nitrite reductase	cation binding ion binding binding calcium ion binding metal ion binding small molecule binding oxidoreductase activity, acting on other nitrogenous compounds as donors, cytochrome as acceptor oxidoreductase activity nitrite reductase (cytochrome, ammonia-forming) activity oxidoreductase activity, acting on other nitrogenous compounds as donors nitrite reductase activity catalytic activity tetrapyrrole binding heme binding	nitrate assimilation nitrogen cycle metabolic process oxoacid metabolic process metabolic process cellular process small molecule metabolic process organic acid metabolic process nitrate metabolic process reactive nitrogen species metabolic process ammonia oxidation cellular respiration energy derivation by oxidation of organic compounds generation of precursor metabolites and energy energy derivation by oxidation of reduced inorganic compounds nitrate assimilation nitrogen cycle metabolic process oxoacid metabolic process metabolic process cellular process small molecule metabolic process organic acid metabolic process nitrate metabolic process reactive nitrogen species metabolic process ammonia oxidation cellular respiration energy derivation by oxidation of organic compounds generation of precursor metabolites and energy energy derivation by oxidation of reduced inorganic compounds anaerobic respiration, using ammonium as electron donor anaerobic respiration anaerobic electron transport chain respiratory electron transport chain electron transport chain	cellular anatomical structure outer membrane-bounded periplasmic space cell envelope periplasmic space

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR036280	Multiheme cytochrome superfamily	Homologous Superfamily
A, B	IPR003321	Cytochrome c552	Family

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. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.