plastid envelope

GO:0009526 · Membrane organelle · Membrane · Proposed

The double lipid bilayer enclosing a plastid and separating its contents from the rest of the cytoplasm; includes the intermembrane space. [GO:0009526]

Synonyms: Plastidic envelope

Part of: plastid (GO:0009536)

Has part: plastid outer membrane (GO:0009527); plastid inner membrane (GO:0009528); plastid intermembrane space (GO:0009529)

Xrefs: uniprot.location:SL-0210 — Plastid envelope

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
plastid outer membrane	Lipid	part of	`GO:0009527`			UNKNOWN	Cytoplasm-facing lipid bilayer of the double plastid envelope. `GO:0009527` GO:0009527 defines plastid outer membrane as the cytoplasm-facing lipid bilayer of the plastid envelope. `uniprot.location:SL-0214` — Plastid outer membrane UniProt SL-0214 identifies plastid outer membrane as the plastid membrane facing the cytoplasm.
plastid inner membrane	Lipid	part of	`GO:0009528`			UNKNOWN	Stroma-facing lipid bilayer that separates the plastid stroma from the plastid intermembrane space. `GO:0009528` GO:0009528 defines plastid inner membrane as the lumen-facing plastid-envelope bilayer that also faces the plastid stroma. `uniprot.location:SL-0211` — Plastid inner membrane UniProt SL-0211 identifies plastid inner membrane as separating the plastid stroma from the intermembrane space.

Taxonomic distribution

NCBITaxon:33090 Viridiplantae — COMMON: Green algae and land plants carry primary plastids with a double plastid envelope derived from cyanobacterial primary endosymbiosis. [DOI:10.1098/rstb.2009.0103]
NCBITaxon:3055 Chlamydomonas reinhardtii — COMMON: The Chlamydomonas reinhardtii chloroplast has a double plastid envelope crossed by TOC-TIC protein-import machinery. [DOI:10.1016/j.cell.2022.10.030]

Canonical examples

NCBITaxon:3055 Chlamydomonas reinhardtii — Green-algal model used to resolve a TOC-TIC supercomplex spanning the two chloroplast envelope membranes. [DOI:10.1016/j.cell.2022.10.030]

Functions

plastid compartmentalization — The double plastid envelope separates plastid contents from the surrounding cytoplasm.
- GO:0009526 GO:0009526 defines the plastid envelope as the double lipid bilayer enclosing a plastid and separating it from the cytoplasm.
- uniprot.location:SL-0210 — Plastid envelope UniProt SL-0210 describes the plastid envelope as comprising the inner and outer plastid membranes plus the intermembrane space.

Mechanism graphs

Plastid envelope delimits the stroma (FUNCTION)

The plastid envelope comprises cytoplasm-facing outer and stroma-facing inner membranes separated by the intermembrane space.

Subject	Predicate	Object	Evidence
plastid envelope	encloses	plastid	`GO:0009526` GO:0009526 defines the plastid envelope as enclosing a plastid and separating its contents from the rest of the cytoplasm.
plastid outer membrane	is part of	plastid envelope	`GO:0009527` GO:0009527 defines the outer membrane by its cytoplasm-facing position in the plastid envelope.
plastid inner membrane	is part of	plastid envelope	`GO:0009528` GO:0009528 defines the inner membrane as the plastid-envelope bilayer that faces the plastid stroma.
plastid envelope	contains	plastid intermembrane space	`GO:0009529` GO:0009529 defines the plastid intermembrane space as the region between the two lipid bilayers of the plastid envelope.
plastid inner membrane	bounds	plastid stroma	`GO:0009528` GO:0009528 defines plastid inner membrane as the bilayer that also faces the plastid stroma. `GO:0009532` GO:0009532 identifies the plastid stroma as the ground substance of plastids.

Discussions

INTERPRETATION (RESOLVED): Keep lineage-specific protein translocases, peptidoglycan, and extra complex-plastid membranes on exact child records. GO:0009526 and UniProt SL-0210 model the primary double plastid envelope as inner membrane, intermembrane space, and outer membrane. Chloroplast, cyanelle, chromatophore, and complex plastid lineages can add specific translocases, peptidoglycan layers, retained outer membranes, or additional host-derived membranes in exact child records.

Evidence

GO:0009526 Gene Ontology cellular-component term for plastid envelope.
GO:0031967 Gene Ontology cellular-component term for organelle envelope.
GO:0009536 Gene Ontology cellular-component term for plastid.
GO:0009527 Gene Ontology cellular-component term for plastid outer membrane.
GO:0009528 Gene Ontology cellular-component term for plastid inner membrane.
GO:0009529 Gene Ontology cellular-component term for plastid intermembrane space.
GO:0009532 Gene Ontology cellular-component term for plastid stroma.
uniprot.location:SL-0210 — Plastid envelope UniProt Subcellular Location entry SL-0210 maps Plastid envelope to GO:0009526.
uniprot.location:SL-0211 — Plastid inner membrane UniProt Subcellular Location entry SL-0211 maps Plastid inner membrane to GO:0009528.
uniprot.location:SL-0212 — Plastid intermembrane space UniProt Subcellular Location entry SL-0212 maps Plastid intermembrane space to GO:0009529.
uniprot.location:SL-0214 — Plastid outer membrane UniProt Subcellular Location entry SL-0214 maps Plastid outer membrane to GO:0009527.
DOI:10.1098/rstb.2009.0103 Keeling 2010, The endosymbiotic origin, diversification and fate of plastids, Philosophical Transactions of the Royal Society B.
DOI:10.1016/j.cell.2022.10.030 Jin et al. 2022, Structure of a TOC-TIC supercomplex spanning two chloroplast envelope membranes, Cell.

Curation history

2026-09-13T20:52:57Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-13T20:54:00Z codex · EXPANDED_RECORD — Added organelle-envelope parentage, plastid parthood, inner/outer membrane and intermembrane-space parts, the UniProt SL-0210 xref, Viridiplantae/Chlamydomonas scope, compartmentalization function, GO/UniProt/DOI evidence, a nonmechanistic envelope topology graph, and a resolved generic-scope interpretation.
2026-09-13T21:01:20Z codex · ADDRESS_REVIEW — Resolved #836 by adding the UniProt SL-0210 exact synonym; resolved #837 by removing the unused cytoplasm node from the plastid envelope topology graph.

Source: data/structures/membrane_organelle/plastid_envelope.yaml