Annotations: 4N4K

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Multi-haem_cyto	e4n4kA1	A: few secondary structure elements	X: Multiheme cytochromes	H: Di-heme elbow motif (From Topology)	T: Di-heme elbow motif	F: Multi-haem_cyto	ECOD (1.6)
A	EUF08663	e4n4kA2	A: few secondary structure elements	X: Multiheme cytochromes	H: Di-heme elbow motif (From Topology)	T: Di-heme elbow motif	F: EUF08663	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF22142	Hydroxylamine oxidoreductase, C-terminal domain (Hao_C)	Hydroxylamine oxidoreductase, C-terminal domain	This domain is found at the C-terminal end of Hydroxylamine oxidoreductase from Kuenenia stuttgartiensis (Hao, Swiss:Q1PX48) and similar bacterial sequences. This enzyme is responsible for the formation of NO from hydroxylamine in aerobic ammonium -o ...	This domain is found at the C-terminal end of Hydroxylamine oxidoreductase from Kuenenia stuttgartiensis (Hao, Swiss:Q1PX48) and similar bacterial sequences. This enzyme is responsible for the formation of NO from hydroxylamine in aerobic ammonium -oxidising bacteria. This domain shows a predominantly alpha -helical structure [1-3].	Domain
A	PF13447	Seven times multi-haem cytochrome CxxCH (Multi-haem_cyto)	Seven times multi-haem cytochrome CxxCH	This domain carries up to seven CxxCH repeated sequence motifs, characteristic of multi-haem cytochromes.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	hydroxylamine oxidoreductase	oxidoreductase activity, acting on other nitrogenous compounds as donors, cytochrome as acceptor oxidoreductase activity oxidoreductase activity, acting on other nitrogenous compounds as donors hydroxylamine oxidoreductase activity catalytic activity binding tetrapyrrole binding heme binding cation binding ion binding metal ion binding small molecule binding identical protein binding protein binding	ammonia oxidation cellular respiration energy derivation by oxidation of organic compounds generation of precursor metabolites and energy nitrogen cycle metabolic process energy derivation by oxidation of reduced inorganic compounds small molecule metabolic process metabolic process cellular process anaerobic respiration, using ammonium as electron donor anaerobic respiration protein-containing complex organization protein trimerization cellular component organization ammonia oxidation cellular respiration energy derivation by oxidation of organic compounds generation of precursor metabolites and energy nitrogen cycle metabolic process energy derivation by oxidation of reduced inorganic compounds small molecule metabolic process metabolic process cellular process anaerobic respiration, using ammonium as electron donor anaerobic respiration protein-containing complex organization protein trimerization cellular component organization cellular component biogenesis cellular component assembly protein homotrimerization protein complex oligomerization protein-containing complex assembly protein homooligomerization cellular component organization or biogenesis nitric oxide metabolic process nitric oxide biosynthetic process biosynthetic process reactive nitrogen species metabolic process	membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure anammoxosome organelle cytoplasm intracellular membrane-bounded organelle

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR051829	Multiheme_Cytochr_ET	Unknown
A	IPR036280	Multiheme cytochrome superfamily	Homologous Superfamily
A	IPR012138	Hydroxylamine oxidase	Family
A	IPR054394	Hydroxylamine oxidoreductase, C-terminal domain	Domain

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.