3LF5

Structure of Human NADH cytochrome b5 oxidoreductase (Ncb5or) b5 Domain to 1.25A Resolution

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
Pharos: Disease Associations

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d3lf5a_	Alpha and beta proteins (a+b)	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5-like heme/steroid binding domain	automated matches	automated matches	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d3lf5b_	Alpha and beta proteins (a+b)	Cytochrome b5-like heme/steroid binding domain	Cytochrome b5-like heme/steroid binding domain	automated matches	automated matches	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	Cytochrome b5	8068626	4000144	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Cytochrome b5-like heme/steroid binding domain	8068627	3000073	SCOP2 (2022-06-29)
B	SCOP2B Superfamily	Cytochrome b5-like heme/steroid binding domain	8068627	3000073	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	Cyt-b5	e3lf5A1	A: a+b two layers	X: Cystatin-like	H: Cytochrome b5-like heme/steroid binding domain (From Topology)	T: Cytochrome b5-like heme/steroid binding domain	F: Cyt-b5	ECOD (1.6)
B	Cyt-b5	e3lf5B1	A: a+b two layers	X: Cystatin-like	H: Cytochrome b5-like heme/steroid binding domain (From Topology)	T: Cytochrome b5-like heme/steroid binding domain	F: Cyt-b5	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.10.120.10	Alpha Beta	Roll	Flavocytochrome B2	Chain A, domain 1	CATH (4.3.0)
B	3.10.120.10	Alpha Beta	Roll	Flavocytochrome B2	Chain A, domain 1	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF00173	Cytochrome b5-like Heme/Steroid binding domain (Cyt-b5)	Cytochrome b5-like Heme/Steroid binding domain	This family includes heme binding domains from a diverse range of proteins. This family also includes proteins that bind to steroids. The family includes progesterone receptors such as Swiss:O00264 [1,2]. Many members of this subfamily are membrane a ...	This family includes heme binding domains from a diverse range of proteins. This family also includes proteins that bind to steroids. The family includes progesterone receptors such as Swiss:O00264 [1,2]. Many members of this subfamily are membrane anchored by an N-terminal transmembrane alpha helix. This family also includes a domain in some chitin synthases. There is no known ligand for this domain in the chitin synthases.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	Cytochrome b5 reductase 4	oxidoreductase activity cytochrome-b5 reductase activity, acting on NAD(P)H oxidoreductase activity, acting on NAD(P)H oxidoreductase activity, acting on NAD(P)H, heme protein as acceptor catalytic activity NAD(P)H oxidase H2O2-forming activity oxidoreductase activity, acting on NAD(P)H, oxygen as acceptor binding tetrapyrrole binding heme binding cation binding ion binding metal ion binding small molecule binding	reactive oxygen species metabolic process metabolic process cellular process superoxide metabolic process response to stimulus response to chemical response to antibiotic localization bicarbonate transport organic anion transport transport establishment of localization developmental process cellular developmental process reactive oxygen species metabolic process metabolic process cellular process superoxide metabolic process response to stimulus response to chemical response to antibiotic localization bicarbonate transport organic anion transport transport establishment of localization developmental process cellular developmental process cell differentiation anatomical structure development cell development detection of stimulus detection of chemical stimulus response to oxygen levels response to abiotic stimulus detection of oxygen protein localization establishment of protein localization cellular localization nitrogen compound transport signaling hormone secretion cell communication protein localization to extracellular region peptide secretion secretion by cell amide transport signal release cellular macromolecule localization regulation of biological quality regulation of biological process secretion regulation of hormone levels biological regulation establishment of protein localization to extracellular region cell-cell signaling export from cell protein secretion peptide transport protein transport peptide hormone secretion macromolecule localization hormone transport insulin secretion chemical homeostasis homeostatic process glucose homeostasis carbohydrate homeostasis	cellular anatomical structure intracellular anatomical structure cytoplasm membrane-bounded organelle organelle subcompartment membrane intracellular membrane-bounded organelle endomembrane system endoplasmic reticulum subcompartment intracellular organelle organelle nuclear outer membrane-endoplasmic reticulum membrane network endoplasmic reticulum organelle membrane cellular anatomical structure intracellular anatomical structure cytoplasm membrane-bounded organelle organelle subcompartment membrane intracellular membrane-bounded organelle endomembrane system endoplasmic reticulum subcompartment intracellular organelle organelle nuclear outer membrane-endoplasmic reticulum membrane network endoplasmic reticulum organelle membrane endoplasmic reticulum membrane perinuclear region of cytoplasm

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR051872	Cytochrome b5/Flavoprotein Reductase	Family
A, B	IPR001433	Oxidoreductase FAD/NAD(P)-binding	Domain
A, B	IPR017938	Riboflavin synthase-like beta-barrel	Homologous Superfamily
A, B	IPR037908	Cytochrome b5 reductase 4, p23 domain	Domain
A, B	IPR008978	HSP20-like chaperone	Homologous Superfamily
A, B	IPR036400	Cytochrome b5-like heme/steroid binding domain superfamily	Homologous Superfamily
A, B	IPR018506	Cytochrome b5, heme-binding site	Binding Site
A, B	IPR039261	Ferredoxin-NADP reductase (FNR), nucleotide-binding domain	Homologous Superfamily
A, B	IPR008333	Flavoprotein pyridine nucleotide cytochrome reductase-like, FAD-binding domain	Domain
A, B	IPR007052	CS domain	Domain
A, B	IPR017927	FAD-binding domain, ferredoxin reductase-type	Domain
A, B	IPR001199	Cytochrome b5-like heme/steroid binding domain	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A, B	Pharos: Q7L1T6	glioblastoma Malignant neoplasm of breast psoriasis IgA glomerulonephritis medulloblastoma Sjogren syndrome lung cancer osteosarcoma

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.