4AU5

Structure of the NhaA dimer, crystallised at low pH

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
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)
A	Na_H_antiport_1	e4au5A1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: Na_H_antiport_1	ECOD (1.6)
B	Na_H_antiport_1	e4au5B1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: Na_H_antiport_1	ECOD (1.6)
C	Na_H_antiport_1	e4au5C1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: Na_H_antiport_1	ECOD (1.6)
D	Na_H_antiport_1	e4au5D1	A: alpha complex topology	X: Cation-proton antiporter	H: Cation-proton antiporter (CPA) (From Topology)	T: Cation-proton antiporter (CPA)	F: Na_H_antiport_1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.20.1530.10	Mainly Alpha	Up-down Bundle	Na+/H+ antiporter like fold	Na+/H+ antiporter like domain	CATH (4.3.0)
B	1.20.1530.10	Mainly Alpha	Up-down Bundle	Na+/H+ antiporter like fold	Na+/H+ antiporter like domain	CATH (4.3.0)
C	1.20.1530.10	Mainly Alpha	Up-down Bundle	Na+/H+ antiporter like fold	Na+/H+ antiporter like domain	CATH (4.3.0)
D	1.20.1530.10	Mainly Alpha	Up-down Bundle	Na+/H+ antiporter like fold	Na+/H+ antiporter like domain	CATH (4.3.0)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C, D	NA(+)/H(+) ANTIPORTER NHAA	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 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 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 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 ion binding binding anion binding phosphatidylglycerol binding phospholipid binding lipid binding cardiolipin binding small molecule binding	response to stimulus response to pH response to alkaline pH response to abiotic stimulus 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 response to stimulus response to pH response to alkaline pH response to abiotic stimulus 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 response to osmotic stress response to stress response to salt stress	cell periphery cellular anatomical structure plasma membrane membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C, D	IPR004670	Na+/H+ antiporter NhaA	Family
A, B, C, D	IPR023171	Na+/H+ antiporter domain superfamily	Homologous Superfamily

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
A, B, C, D	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
A, B, C, D	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
A, B, C, D	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	Antiporters	NhaA Na⁺/H⁺ antiporter in dimeric state (inward-facing)

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.