Annotations: 6Z3Y

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A [auth B]	PF00999	e6z3yB1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: PF00999	ECOD (1.6)
B [auth A]	PF00999	e6z3yA1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: PF00999	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A [auth B], B [auth A]	PF00999	Sodium/hydrogen exchanger family (Na_H_Exchanger)	Sodium/hydrogen exchanger family	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth B], B [auth A]	Sodium/hydrogen exchanger	monoatomic cation transmembrane transporter activity metal cation:monoatomic cation antiporter activity proton transmembrane transporter activity sodium:proton antiporter activity sodium ion transmembrane transporter activity secondary active transmembrane transporter activity antiporter activity active monoatomic ion transmembrane transporter activity metal cation:proton antiporter activity active transmembrane transporter activity inorganic molecular entity transmembrane transporter activity inorganic cation transmembrane transporter activity monoatomic ion transmembrane transporter activity transporter activity metal ion transmembrane transporter activity monoatomic cation transmembrane transporter activity metal cation:monoatomic cation antiporter activity proton transmembrane transporter activity sodium:proton antiporter activity sodium ion transmembrane transporter activity secondary active transmembrane transporter activity antiporter activity active monoatomic ion transmembrane transporter activity metal cation:proton antiporter activity active transmembrane transporter activity inorganic molecular entity transmembrane transporter activity inorganic cation transmembrane transporter activity monoatomic ion transmembrane transporter activity transporter activity metal ion transmembrane transporter activity transmembrane transporter activity identical protein binding protein binding binding protein homodimerization activity protein dimerization activity potassium ion transmembrane transporter activity potassium:proton antiporter activity solute:potassium antiporter activity	transport proton transmembrane transport monoatomic ion transmembrane transport inorganic ion transmembrane transport establishment of localization inorganic cation transmembrane transport transmembrane transport monoatomic cation transmembrane transport localization monoatomic ion transport cellular process monoatomic cation transport import into cell import across plasma membrane transport proton transmembrane transport monoatomic ion transmembrane transport inorganic ion transmembrane transport establishment of localization inorganic cation transmembrane transport transmembrane transport monoatomic cation transmembrane transport localization monoatomic ion transport cellular process monoatomic cation transport import into cell import across plasma membrane sodium ion import across plasma membrane sodium ion transmembrane transport inorganic cation import across plasma membrane metal ion transport inorganic ion import across plasma membrane sodium ion transport potassium ion transmembrane transport potassium ion transport homeostatic process biological regulation regulation of intracellular pH cellular homeostasis chemical homeostasis intracellular monoatomic cation homeostasis regulation of pH monoatomic ion homeostasis intracellular chemical homeostasis regulation of biological quality monoatomic cation homeostasis regulation of cellular pH intracellular monoatomic ion homeostasis	membrane-bounded organelle intracellular anatomical structure membrane intracellular vesicle phagocytic vesicle cellular anatomical entity intracellular membrane-bounded organelle intracellular organelle phagocytic vesicle membrane cytoplasmic vesicle membrane bounding membrane of organelle cytoplasmic vesicle vesicle membrane organelle membrane-bounded organelle intracellular anatomical structure membrane intracellular vesicle phagocytic vesicle cellular anatomical entity intracellular membrane-bounded organelle intracellular organelle phagocytic vesicle membrane cytoplasmic vesicle membrane bounding membrane of organelle cytoplasmic vesicle vesicle membrane organelle endocytic vesicle membrane cytoplasm vesicle organelle membrane endocytic vesicle endosome membrane endosome recycling endosome endomembrane system recycling endosome membrane early endosome early endosome membrane cell periphery plasma membrane late endosome membrane late endosome

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A [auth B], B [auth A]	IPR018422	Cation/H+ exchanger, CPA1 family	Family
A [auth B], B [auth A]	IPR006153	Cation/H+ exchanger	Domain
A [auth B], B [auth A]	IPR002090	Sodium/hydrogen exchanger 6/7/9	Family
A [auth B], B [auth A]	IPR004709	Na+/H+ exchanger	Family

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
A [auth B], B [auth A]	OPM	Transmembrane	Alpha-helical polytopic	Monovalent cation-proton antiporter	Sodium-proton antiporter 1

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A [auth B], B [auth A]	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A [auth B], B [auth A]	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A [auth B], B [auth A]	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Antiporters	Na⁺/H⁺ exchanger NHE9 (SLC9A9), inward-facing 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 R01GM133198.