Annotations: 3QNT

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	NPC1 N-terminal domain-like	8045541	4004525	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Frizzled domain-like	8090918	3001950	SCOP2 (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	NPC1_N	e3qntA1	A: few secondary structure elements	X: Frizzled cysteine-rich domain-related (From Topology)	H: Frizzled cysteine-rich domain-related (From Topology)	T: Frizzled cysteine-rich domain-related	F: NPC1_N	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF16414	Niemann-Pick C1 N terminus (NPC1_N)	Niemann-Pick C1 N terminus	This is the N-terminal domain of Niemann-Pick C1 family proteins. This family of proteins mediates transport of cholesterol from the intestinal lumen to enterocytes. This domain contains a cholesterol-binding pocket [1-2].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Niemann-Pick C1-like protein 1	small GTPase binding protein binding binding enzyme binding GTPase binding identical protein binding protein homodimerization activity protein dimerization activity sterol binding organic cyclic compound binding alcohol binding steroid binding lipid binding cholesterol binding small GTPase binding protein binding binding enzyme binding GTPase binding identical protein binding protein homodimerization activity protein dimerization activity sterol binding organic cyclic compound binding alcohol binding steroid binding lipid binding cholesterol binding small molecule binding cytoskeletal protein binding myosin V binding myosin binding vitamin binding heterocyclic compound binding vitamin E binding	localization transport vitamin transport establishment of localization intestinal lipid absorption multicellular organismal process digestion system process intestinal absorption digestive system process intestinal cholesterol absorption lipid digestion vitamin E metabolic process fat-soluble vitamin metabolic process localization transport vitamin transport establishment of localization intestinal lipid absorption multicellular organismal process digestion system process intestinal absorption digestive system process intestinal cholesterol absorption lipid digestion vitamin E metabolic process fat-soluble vitamin metabolic process organic hydroxy compound metabolic process metabolic process cellular process small molecule metabolic process vitamin metabolic process lipoprotein metabolic process primary metabolic process protein metabolic process macromolecule metabolic process cellular response to stimulus cellular response to stress response to stimulus cellular response to sterol depletion response to stress response to sterol depletion macromolecule localization lipid localization cholesterol transport lipid transport sterol transport organic hydroxy compound transport sterol homeostasis chemical homeostasis homeostatic process cholesterol homeostasis lipid homeostasis secondary alcohol biosynthetic process small molecule biosynthetic process cholesterol biosynthetic process sterol metabolic process steroid metabolic process cholesterol metabolic process lipid biosynthetic process alcohol metabolic process secondary alcohol metabolic process biosynthetic process sterol biosynthetic process organic hydroxy compound biosynthetic process alcohol biosynthetic process steroid biosynthetic process lipid metabolic process	membrane-bounded organelle intracellular anatomical structure membrane intracellular vesicle intracellular membrane-bounded organelle intracellular organelle cytoplasmic vesicle membrane cellular anatomical structure vesicle membrane cytoplasmic vesicle organelle cytoplasm vesicle organelle membrane membrane-bounded organelle intracellular anatomical structure membrane intracellular vesicle intracellular membrane-bounded organelle intracellular organelle cytoplasmic vesicle membrane cellular anatomical structure vesicle membrane cytoplasmic vesicle organelle cytoplasm vesicle organelle membrane cell periphery apical part of cell plasma membrane plasma membrane region apical plasma membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR053956	NPC1, middle luminal domain	Domain
A	IPR032190	Niemann-Pick C1, N-terminal	Domain
A	IPR003392	Patched domain-containing protein, SSD domain	Domain
A	IPR000731	Sterol-sensing domain	Domain
A	IPR053958	HMGCR/SNAP/NPC1-like, sterol-sensing domain	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A	Pharos: Q9UHC9	sitosterolemia facioscapulohumeral muscular dystrophy Familial hypercholesterolemia - homozygous malignant pancreatic neoplasm pancreatic intraductal papillary-mucinous neoplasm with low grade dysplasia familial hyperlipidemia ovarian cancer pancreatic intraductal papillary-mucinous carcinoma ulcerative colitis

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.