EmrE multidrug transporter complex

GO:1990207 · Other · Multiprotein complex · Proposed

A transmembrane protein complex capable of transporting positively charged hydrophobic drugs across the plasma membrane thereby involved in conferring resistance to a wide range of toxic compounds (e.g. methyl viologen, ethidium bromide and acriflavine). It is commonly found in bacteria. In E. coli it forms a homodimer. [GO:1990207]

Synonyms: EmrE complex

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
Multidrug transporter EmrE	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	emrE	2 copies per E. coli EmrE homodimer in PDB:3B5D biological assembly 1	UNKNOWN	Small multidrug resistance transporter subunit that forms an antiparallel homodimer to export toxic hydrophobic cations. `GO:1990207` GO:1990207 defines the EmrE multidrug transporter complex as the E. coli homodimer. `PDB:3B5D` RCSB describes PDB:3B5D biological assembly 1 as an E. coli EmrE homo-2-mer. `PMID:18024586` The PDB:3B5D primary paper reported the EmrE X-ray structure and its dual-topology model.

Organism-specific protein examples

Named proteins in which each component's role was established, with the organism the evidence comes from. The component above is the taxon-agnostic family; these are the specific entries behind it.

Multidrug transporter EmrE

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P23895`	Multidrug transporter EmrE	emrE	Escherichia coli K-12 (`NCBITaxon:83333`)	REVIEWED
Role and evidence (2 references) Reviewed E. coli K-12 EmrE accession mapped by RCSB to the homodimeric polymer entity in PDB:3B5D. `UniProtKB:P23895` UniProtKB P23895 is the reviewed E. coli K-12 entry for EmrE. `PDB:3B5D` RCSB maps PDB:3B5D polymer entity 1 to UniProtKB:P23895.

Taxonomic distribution

NCBITaxon:2 Bacteria — VARIABLE: GO:1990207 defines EmrE as a multidrug transporter complex commonly found in bacteria, so it is represented as variable within Bacteria rather than universal. [GO:1990207]

Canonical examples

NCBITaxon:562 Escherichia coli — E. coli source of the homodimeric EmrE multidrug transporter structure deposited as PDB:3B5D. [PDB:3B5D]

Functions

xenobiotic transmembrane transporter activity GO:0042910 — EmrE homodimers export positively charged hydrophobic xenobiotics across the plasma membrane.
- GO:1990207 GO:1990207 defines the complex by transport of positively charged hydrophobic drugs across the plasma membrane.
- GO:0042910 GO:0042910 is the molecular-function term for xenobiotic transmembrane transporter activity.

Physical properties

SUBUNIT_COUNT: 2 (E. coli EmrE homodimer in PDB:3B5D biological assembly 1) [PDB:3B5D]

Discussions

CURATION_TODO (OPEN): Resolve an exact source-neutral family grounding for the EmrE multidrug transporter component. The first record uses the reviewed E. coli EmrE label and avoids grounding to InterPro small-drug, small-multidrug, or EmrE-superfamily entries that are broader than the exact EmrE constituent.

Evidence

GO:1990207 Gene Ontology cellular-component term for the EmrE multidrug transporter complex.
GO:1902495 QuickGO reports GO:1990207 as an is-a child of GO:1902495 transmembrane transporter complex.
GO:0042910 Gene Ontology molecular-function term for xenobiotic transmembrane transporter activity.
UniProtKB:P23895 UniProtKB reviewed E. coli K-12 EmrE entry.
PDB:3B5D RCSB Protein Data Bank entry for the E. coli EmrE multidrug transporter homodimer.
PMID:18024586 PubMed identifier for the PDB:3B5D X-ray EmrE structural paper cited by GO:1990207.
DOI:10.1073/pnas.0709387104 DOI for 'X-ray structure of EmrE supports dual topology model' as reported by RCSB and PubMed.

Curation history

2026-10-01T19:54:45Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-01T19:55:44Z codex · EXPANDED_RECORD — Added GO synonymy and transmembrane-transporter parentage, an EmrE reviewed-label-only component with an E. coli K-12 UniProt example, the PDB:3B5D homodimer, xenobiotic transporter function, taxonomy, and a component-grounding discussion.

Source: data/structures/other/emre_multidrug_transporter_complex.yaml