7NIU | pdb_00007niu

Nanodisc reconstituted human ABCB4 in complex with 4B1-Fab and QA2-Fab (apo-inward-open conformation)

External Resource: Annotation

Domain Annotation: ECOD Classification
SAbDab Antibody Annotation
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Pharos: Disease Associations
Membrane Protein Annotation: OPM
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD
Membrane Protein Annotation: mpstruc

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
E [auth C]	V-set_8	e7niuC1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
E [auth C]	C1-set_1	e7niuC2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
D [auth B]	C1-set_4	e7niuB2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_4	ECOD (1.6)
D [auth B]	V-set	e7niuB1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set	ECOD (1.6)
C [auth E]	V-set_8	e7niuE1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
C [auth E]	C1-set_1	e7niuE2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
B [auth D]	C1-set_4	e7niuD2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_4	ECOD (1.6)
B [auth D]	V-set	e7niuD1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set	ECOD (1.6)
A	ABC_membrane	e7niuA3	A: alpha bundles	X: Type II ABC exporter transmembrane domain fold	H: Type I ABC exporter transmembrane domain fold (From Topology)	T: Type I ABC exporter transmembrane domain fold	F: ABC_membrane	ECOD (1.6)
A	ABC_tran_1	e7niuA1	A: a/b three-layered sandwiches	X: P-loop domains-like	H: P-loop domains-related	T: P-loop containing nucleoside triphosphate hydrolases	F: ABC_tran_1	ECOD (1.6)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
E [auth C]	Heavy Chain	IGHV3	-	isoform 2 of phosphatidylcholine translocator abcb4	SAbDab (2025-12-19)
D [auth B]	Light Chain	IGKV1	Kappa	isoform 2 of phosphatidylcholine translocator abcb4	SAbDab (2025-12-19)
C [auth E]	Heavy Chain	IGHV3	-	isoform 2 of phosphatidylcholine translocator abcb4	SAbDab (2025-12-19)
B [auth D]	Light Chain	IGKV1	Kappa	isoform 2 of phosphatidylcholine translocator abcb4	SAbDab (2025-12-19)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00664	ABC transporter transmembrane region (ABC_membrane)	ABC transporter transmembrane region	-	Family
A	PF00005	ABC transporter (ABC_tran)	ABC transporter	ABC transporters for a large family of proteins responsible for translocation of a variety of compounds across biological membranes. ABC transporters are the largest family of proteins in many completely sequenced bacteria. ABC transporters are comp ...	ABC transporters for a large family of proteins responsible for translocation of a variety of compounds across biological membranes. ABC transporters are the largest family of proteins in many completely sequenced bacteria. ABC transporters are composed of two copies of this domain and two copies of a transmembrane domain Pfam:PF00664. These four domains may belong to a single polypeptide as in Swiss:P13569, or belong in different polypeptide chains.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
E [auth C]	4B1 Fab-fragment heavy chain	-	-	-
D [auth B]	4B1 Fab-fragment light chain	-	-	-
C [auth E]	QA2 Fab-fragment heavy chain	-	-	-
B [auth D]	QA2 Fab-fragment light chain	-	-	-
A	Isoform 2 of Phosphatidylcholine translocator ABCB4	phosphatidylcholine transporter activity ATPase-coupled intramembrane lipid transporter activity lipid transporter activity intramembrane lipid transporter activity phosphatidylcholine floppase activity transporter activity floppase activity phospholipid transporter activity ATP-dependent activity ABC-type transporter activity active transmembrane transporter activity primary active transmembrane transporter activity ATPase-coupled transmembrane transporter activity transmembrane transporter activity phosphatidylcholine transporter activity ATPase-coupled intramembrane lipid transporter activity lipid transporter activity intramembrane lipid transporter activity phosphatidylcholine floppase activity transporter activity floppase activity phospholipid transporter activity ATP-dependent activity ABC-type transporter activity active transmembrane transporter activity primary active transmembrane transporter activity ATPase-coupled transmembrane transporter activity transmembrane transporter activity binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding pyrophosphatase activity ATP hydrolysis activity ribonucleoside triphosphate phosphatase activity hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides hydrolase activity hydrolase activity, acting on acid anhydrides catalytic activity	cellular response to stimulus cellular response to bile acid response to lipid response to stimulus response to oxygen-containing compound cellular response to oxygen-containing compound cellular response to chemical stimulus response to bile acid response to chemical cellular response to lipid cellular process regulation of localization regulation of phospholipid transport positive regulation of cellular component organization cellular response to stimulus cellular response to bile acid response to lipid response to stimulus response to oxygen-containing compound cellular response to oxygen-containing compound cellular response to chemical stimulus response to bile acid response to chemical cellular response to lipid cellular process regulation of localization regulation of phospholipid transport positive regulation of cellular component organization regulation of cellular process regulation of cellular component organization transport phospholipid translocation positive regulation of biological process phospholipid transport regulation of lipid transport cellular component organization localization cellular component organization or biogenesis regulation of biological quality positive regulation of cellular process membrane organization regulation of biological process regulation of transport biological regulation lipid localization regulation of phospholipid translocation lipid transport positive regulation of lipid localization establishment of localization lipid translocation regulation of membrane lipid distribution positive regulation of phospholipid translocation positive regulation of lipid transport positive regulation of transport regulation of lipid localization macromolecule localization positive regulation of phospholipid transport organophosphate ester transport chemical homeostasis homeostatic process lipid homeostasis primary metabolic process metabolic process lipid metabolic process transmembrane transport organic acid transport bile acid secretion organic anion transport monocarboxylic acid transport carboxylic acid transport secretion acid secretion response to ketone response to ether response to fenofibrate positive regulation of sterol transport organic hydroxy compound transport sterol transport regulation of cholesterol transport positive regulation of cholesterol transport regulation of sterol transport cholesterol transport	cellular anatomical structure anchoring junction cell junction focal adhesion cell-substrate junction cell-cell junction intercellular canaliculus membrane cell periphery apical part of cell plasma membrane plasma membrane region apical plasma membrane membrane-bounded organelle cellular anatomical structure anchoring junction cell junction focal adhesion cell-substrate junction cell-cell junction intercellular canaliculus membrane cell periphery apical part of cell plasma membrane plasma membrane region apical plasma membrane membrane-bounded organelle intracellular anatomical structure intracellular vesicle intracellular membrane-bounded organelle intracellular organelle cytoplasmic vesicle organelle clathrin-coated vesicle coated vesicle cytoplasm vesicle extracellular exosome extracellular vesicle extracellular organelle extracellular region extracellular space extracellular membrane-bounded organelle cytosol membrane microdomain membrane raft nucleus membrane-enclosed lumen intracellular organelle lumen nucleoplasm organelle lumen nuclear lumen

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR003439	ABC transporter-like, ATP-binding domain	Domain
A	IPR003593	AAA+ ATPase domain	Domain
A	IPR011527	ABC transporter type 1, transmembrane domain	Domain
A	IPR027417	P-loop containing nucleoside triphosphate hydrolase	Homologous Superfamily
A	IPR017871	ABC transporter-like, conserved site	Conserved Site
A	IPR036640	ABC transporter type 1, transmembrane domain superfamily	Homologous Superfamily
A	IPR039421	Type 1 protein exporter	Family

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A	Pharos: P21439	sclerosing cholangitis progressive familial intrahepatic cholestasis type 3 intrahepatic cholestasis cholangitis primary biliary cholangitis low phospholipid associated cholelithiasis cholestasis, intrahepatic, of pregnancy 3 obstructive jaundice cirrhosis of liver Inflammation cholelithiasis non-alcoholic fatty liver disease colorectal cancer primary sclerosing cholangitis cholestasis sclerosing cholangitis progressive familial intrahepatic cholestasis type 3 intrahepatic cholestasis cholangitis primary biliary cholangitis low phospholipid associated cholelithiasis cholestasis, intrahepatic, of pregnancy 3 obstructive jaundice cirrhosis of liver Inflammation cholelithiasis non-alcoholic fatty liver disease colorectal cancer primary sclerosing cholangitis cholestasis progressive familial intrahepatic cholestasis progressive familial intrahepatic cholestasis type 1 gallbladder disease adenoma liver disease malignant glioma ovarian cancer peripheral neuropathy cutaneous lupus erythematosus glioblastoma alopecia medulloblastoma pancreatic ductal adenocarcinoma chronic liver failure pilocytic astrocytoma colorectal carcinoma psoriasis gallbladder cancer hepatocellular carcinoma lymphoplasmacytic lymphoma cholecystitis myopathy cholestasis, intrahepatic, of pregnancy, 1 peripheral nervous system disease

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
A	OPM	Transmembrane	Alpha-helical polytopic	ABC transporters	Multidrug resistance exporter (MDR)

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	ATP Binding Cassette (ABC) Transporters	ABCB4 (MDR3) phospholipid transporter, apo-inward-open conformation

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.