Annotations: 6W0D

Open-gate KcsA soaked in 5 mM BaCl2

External Resource: Annotation

Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD
Membrane Protein Annotation: mpstruc

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
C	SCOP2B Superfamily	Voltage-gated potassium channels	8003437	3000023	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	SBP_bac_1	e6w0dA1	A: beta barrels	X: Tail specific protease helical domain	H: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	T: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	F: SBP_bac_1	ECOD (v294.2)
B	SBP_bac_1	e6w0dB1	A: beta barrels	X: Tail specific protease helical domain	H: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	T: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	F: SBP_bac_1	ECOD (v294.2)
C	SBP_bac_1	e6w0dC1	A: beta barrels	X: Tail specific protease helical domain	H: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	T: Anticodon-binding domain of a subclass of class I aminoacyl-tRNA synthetases	F: SBP_bac_1	ECOD (v294.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
B	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
C	1.10.287.70	Mainly Alpha	Orthogonal Bundle	Helix Hairpins		CATH (utative)

IMGT Antibody Annotation IMGT Database Homepage

Chain	Protein Name	Description	Organism Name	Gene Allele Name(s)	Domain Name(s)	Receptor Type	Receptor Description	Provenance Source
A	FAB HEAVY CHAIN,B	VH-CH1	Mus musculus (house mouse)	IGHV1S8102, IGHJ101, IGHJ102, IGHG102	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202618-0)
B	FAB HEAVY CHAIN,B	L-KAPPA	Mus musculus (house mouse)	IGKV5-4801, IGKJ401, IGKC01, IGKC02	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202618-0)
C	house mouse	null	Mus musculus (house mouse)	-	-	TR	GH1	IMGT (202618-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
A	Heavy Chain	IGHV1	-	ph-gated potassium channel kcsa	SAbDab (2026-05-15)
B	Light Chain	IGKV5	Kappa	ph-gated potassium channel kcsa	SAbDab (2026-05-15)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Fab Heavy Chain	-	-	-
B	Fab Light Chain	-	-	-
C	pH-gated potassium channel KcsA	monoatomic cation transmembrane transporter activity gated channel activity monoatomic ion channel activity potassium ion transmembrane transporter activity voltage-gated channel activity voltage-gated monoatomic ion channel activity potassium channel activity voltage-gated monoatomic cation channel activity monoatomic cation channel activity passive transmembrane transporter activity voltage-gated potassium channel activity channel activity monoatomic ion transmembrane transporter activity transporter activity metal ion transmembrane transporter activity monoatomic cation transmembrane transporter activity gated channel activity monoatomic ion channel activity potassium ion transmembrane transporter activity voltage-gated channel activity voltage-gated monoatomic ion channel activity potassium channel activity voltage-gated monoatomic cation channel activity monoatomic cation channel activity passive transmembrane transporter activity voltage-gated potassium channel activity channel activity monoatomic ion transmembrane transporter activity transporter activity metal ion transmembrane transporter activity transmembrane transporter activity identical protein binding protein binding binding	biological regulation action potential regulation of biological quality regulation of membrane potential	voltage-gated potassium channel complex protein-containing complex plasma membrane protein complex membrane plasma membrane potassium channel complex membrane protein complex cation channel complex transporter complex cell periphery cellular anatomical structure transmembrane transporter complex monoatomic ion channel complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C	IPR013099	Potassium channel domain	Domain
C	IPR028325	Voltage-gated potassium channel	Family

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

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

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

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

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
C	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Channels: Potassium, Sodium, & Proton Ion-Selective	KcsA Potassium channel, open state. Barium blocked. 1 mM BaCl₂

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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. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.