cell outer membrane
The outermost lipid bilayer of a diderm cell envelope. In canonical Gram-negative bacteria it is asymmetric, with phospholipid enriched in the inner leaflet and lipopolysaccharide enriched in the outer leaflet, and contains beta-barrel proteins that mediate transport and assembly. [DOI:10.1101/cshperspect.a000414]
Synonyms: outer membrane of cell
Components
| Component | Type | Grounding | Genes | Stoichiometry | Essential | Role |
|---|---|---|---|---|---|---|
| lipopolysaccharide-rich outer leaflet | LIPID | CONDITIONAL | Creates the characteristic asymmetric permeability barrier in canonical Gram-negative bacteria.
| |||
| outer-membrane beta-barrel proteins | PROTEIN | ESSENTIAL | Provide selective transport and envelope assembly functions.
|
Taxonomic distribution
NCBITaxon:2Bacteria — VARIABLE: A diderm feature; monoderm bacteria lack an outer membrane. [DOI:10.1101/cshperspect.a000414]
Canonical examples
NCBITaxon:562Escherichia coli — Canonical model for outer-membrane composition and biogenesis. [DOI:10.1101/cshperspect.a000414]
Functions
- selective permeability barrier — Limits entry of harmful compounds while porins admit selected solutes.
DOI:10.1101/cshperspect.a000414The outer membrane protects against environmental insults.
Evidence
DOI:10.1101/cshperspect.a000414The bacterial cell envelope.
Curation history
2026-08-30T19:30:00Zcodex · CREATED_RECORD — Added as a literature-backed foundational seed. Identity checked against the 2026-07-01 Gene Ontology release; requires human review.