mitochondrial intermembrane space

GO:0005758 · Membrane organelle · Subcellular region · Proposed

The region between the inner and outer lipid bilayers of the mitochondrial envelope. [GO:0005758]

Synonyms: mitochondrial envelope lumen; mitochondrial membrane lumen

Part of: mitochondrial envelope (GO:0005740)

Taxonomic distribution

NCBITaxon:2759 Eukaryota — VARIABLE: Canonical mitochondrial intermembrane spaces occur with canonical mitochondria in eukaryotes, while some anaerobic lineages carry reduced mitochondrion-related organelles instead. [GO:0005758]
NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding-yeast mitochondria contain an intermembrane space traversed by precursor proteins after outer-membrane TOM entry and before downstream inner-membrane sorting. [DOI:10.1016/j.cell.2009.08.005]

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model for mitochondrial protein-import studies across the outer membrane, intermembrane space, and inner membrane. [DOI:10.1016/j.cell.2009.08.005]

The mitochondrial intermembrane space is the envelope lumen between the inner and outer mitochondrial membranes.

Subject	Predicate	Object	Evidence
mitochondrial intermembrane space	is part of	mitochondrial envelope	`GO:0005758` GO:0005758 defines the intermembrane space as the region between the inner and outer lipid bilayers of the mitochondrial envelope. `GO:0005740` GO:0005740 defines the mitochondrial envelope as the double lipid bilayer enclosing the mitochondrion and including the intermembrane space.
mitochondrial outer membrane	delimits	mitochondrial intermembrane space	`GO:0005758` GO:0005758 defines this space by its position between the two mitochondrial-envelope bilayers. `GO:0005741` GO:0005741 identifies the outer lipid bilayer of the mitochondrial envelope.
mitochondrial inner membrane	delimits	mitochondrial intermembrane space	`GO:0005758` GO:0005758 defines this space by its position between the two mitochondrial-envelope bilayers. `GO:0005743` GO:0005743 identifies the inner lipid bilayer of the mitochondrial envelope.

GO:0005758 Gene Ontology cellular-component term for mitochondrial intermembrane space.
GO:0031970 Gene Ontology cellular-component parent term for organelle envelope lumen.
GO:0005740 Gene Ontology cellular-component term for the mitochondrial envelope that contains the intermembrane space.
GO:0005741 Gene Ontology cellular-component term for the outer mitochondrial bilayer that delimits this space.
GO:0005743 Gene Ontology cellular-component term for the inner mitochondrial bilayer that delimits this space.
DOI:10.1016/j.cell.2009.08.005 Chacinska et al. 2009, 'Importing mitochondrial proteins: machineries and mechanisms', Cell.

2026-09-14T00:29:49Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-14T00:30:40Z codex · EXPANDED_RECORD — Added GO parentage, mitochondrial-envelope parthood, GO synonyms, Eukaryota and Saccharomyces scope, DOI/GO evidence, and a nonmechanistic intermembrane-space topology graph.