Annotations: 5T5N

Calcium-activated chloride channel bestrophin-1 (BEST1), triple mutant: I76A, F80A, F84A; in complex with an Fab antibody fragment, chloride, and calcium

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
SAbDab Antibody Annotation
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD
Membrane Protein Annotation: mpstruc

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
O	d5t5no1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
O	d5t5no2	Artifacts	Tags	Tags	Tags	N-terminal Tags	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
M	d5t5nm1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
M	d5t5nm2	Artifacts	Tags	Tags	Tags	N-terminal Tags	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
K	d5t5nk1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
K	d5t5nk2	Artifacts	Tags	Tags	Tags	N-terminal Tags	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
I	d5t5ni1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
I	d5t5ni2	Artifacts	Tags	Tags	Tags	N-terminal Tags	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
G	d5t5ng1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	V set domains (antibody variable domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
G	d5t5ng2	Artifacts	Tags	Tags	Tags	N-terminal Tags	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
N	d5t5nn2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
N	d5t5nn1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
L	d5t5nl2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
L	d5t5nl1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
J	d5t5nj2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
J	d5t5nj1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
H	d5t5nh2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
H	d5t5nh1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
F	d5t5nf2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)
F	d5t5nf1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	(Mus musculus ) [TaxId: 10090 ],	SCOPe (2.08)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
O	Dynamin_N	e5t5nO1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
M	Dynamin_N	e5t5nM1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
K	Dynamin_N	e5t5nK1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
I	Dynamin_N	e5t5nI1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
G	Dynamin_N	e5t5nG1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
N	Dynamin_N	e5t5nN1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
L	Dynamin_N	e5t5nL1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
J	Dynamin_N	e5t5nJ1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
H	Dynamin_N	e5t5nH1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
F	Dynamin_N	e5t5nF1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
E	Dynamin_N	e5t5nE1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
D	Dynamin_N	e5t5nD1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
C	Dynamin_N	e5t5nC1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
B	Dynamin_N	e5t5nB1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)
A	Dynamin_N	e5t5nA1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleic acid-binding protein	F: Dynamin_N	ECOD (v295.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
O	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
M	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
K	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
I	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
G	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
N	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
L	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
J	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
H	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
F	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
G, I, K, M, O	Heavy Chain	IGHV1	-	bestrophin-1 (best1)	SAbDab (2026-10-02)
F, H, J, L, N	Light Chain	IGKV12	Kappa	bestrophin-1 (best1)	SAbDab (2026-10-02)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
G, I, K, M, O	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain		Domain
A, B, C, D, E	PF01062	Bestrophin, RFP-TM, chloride channel (Bestrophin)	Bestrophin, RFP-TM, chloride channel	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
G, I, K, M, O	Fab antibody fragment, heavy chain (10D10)	-	-	cellular anatomical structure extracellular region
F, H, J, L, N	Fab antibody fragment, light chain (10D10)	-	-	cell periphery cellular anatomical structure plasma membrane membrane extracellular region
A, B, C, D, E	bestrophin-1 (BEST1)	bicarbonate transmembrane transporter activity passive transmembrane transporter activity bicarbonate channel activity channel activity transporter activity transmembrane transporter activity monoatomic anion transmembrane transporter activity chloride transmembrane transporter activity monoatomic ion channel activity monoatomic anion channel activity monoatomic ion transmembrane transporter activity chloride channel activity identical protein binding protein binding bicarbonate transmembrane transporter activity passive transmembrane transporter activity bicarbonate channel activity channel activity transporter activity transmembrane transporter activity monoatomic anion transmembrane transporter activity chloride transmembrane transporter activity monoatomic ion channel activity monoatomic anion channel activity monoatomic ion transmembrane transporter activity chloride channel activity identical protein binding protein binding binding gated channel activity intracellularly calcium-gated channel activity intracellularly calcium-gated chloride channel activity ligand-gated monoatomic anion channel activity ligand-gated channel activity ligand-gated monoatomic ion channel activity	cellular component organization cellular component biogenesis cellular component assembly protein-containing complex organization protein complex oligomerization protein-containing complex assembly cellular process cellular component organization or biogenesis localization transepithelial chloride transport transepithelial transport transport monoatomic anion transport monoatomic ion transport cellular component organization cellular component biogenesis cellular component assembly protein-containing complex organization protein complex oligomerization protein-containing complex assembly cellular process cellular component organization or biogenesis localization transepithelial chloride transport transepithelial transport transport monoatomic anion transport monoatomic ion transport establishment of localization chloride transport inorganic anion transport nitrogen compound transport carboxylic acid transport secretion export from cell organic acid transport amino acid transport acidic amino acid transport secretion by cell dicarboxylic acid transport glutamate secretion monoatomic ion transmembrane transport transmembrane transport chloride transmembrane transport monoatomic anion transmembrane transport regulation of synaptic plasticity trans-synaptic signaling regulation of biological process regulation of signaling regulation of cellular process modulation of chemical synaptic transmission signaling biological regulation cell-cell signaling chemical synaptic transmission cell communication synaptic signaling regulation of trans-synaptic signaling anterograde trans-synaptic signaling regulation of cell communication regulation of biological quality cellular localization gamma-aminobutyric acid transport signal release establishment of localization in cell synaptic transmission, GABAergic gamma-aminobutyric acid secretion neurotransmitter secretion acid secretion neurotransmitter transport signal release from synapse gamma-aminobutyric acid secretion, neurotransmission	protein-containing complex cellular anatomical structure transmembrane transporter complex membrane chloride channel complex membrane protein complex transporter complex monoatomic ion channel complex membrane microdomain cell periphery plasma membrane basal part of cell basal plasma membrane plasma membrane region protein-containing complex cellular anatomical structure transmembrane transporter complex membrane chloride channel complex membrane protein complex transporter complex monoatomic ion channel complex membrane microdomain cell periphery plasma membrane basal part of cell basal plasma membrane plasma membrane region basolateral plasma membrane presynapse synapse cell junction

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
G, I, K, M, O	IPR003597	Immunoglobulin C1-set	Domain
G, I, K, M, O	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
G, I, K, M, O	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
G, I, K, M, O	IPR007110	Immunoglobulin-like domain	Domain
G, I, K, M, O	IPR050380	Immune Recognition and Response Modulators	Family
F, H, J, L, N	IPR003597	Immunoglobulin C1-set	Domain
F, H, J, L, N	IPR050150	Immunoglobulin Variable Light Chain	Family
F, H, J, L, N	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
F, H, J, L, N	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
F, H, J, L, N	IPR013106	Immunoglobulin V-set domain	Domain
F, H, J, L, N	IPR003599	Immunoglobulin domain subtype	Domain
F, H, J, L, N	IPR007110	Immunoglobulin-like domain	Domain
F, H, J, L, N	IPR003006	Immunoglobulin/major histocompatibility complex, conserved site	Conserved Site
A, B, C, D, E	IPR000615	Bestrophin	Family
A, B, C, D, E	IPR021134	Bestrophin-like	Family

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A, B, C, D, E A, B, C, D, E, F, H, J, L, N	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A, B, C, D, E A, B, C, D, E, F, H, J, L, N	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A, B, C, D, E A, B, C, D, E, F, H, J, L, N	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Channels: Other Ion Channels	Bestrophin-1 (BEST1) Ca²⁺-activated Cl^- channel I76A, F80A, F84A mutant