mitochondrial inner membrane peptidase complex

GO:0042720 · Other · Multiprotein complex · Proposed

Protease complex of the mitochondrial inner membrane, consisting of at least two subunits, involved in processing of both nuclear- and mitochondrially-encoded proteins targeted to the intermembrane space. [GO:0042720]

Synonyms: mitochondrion inner membrane peptidase complex; IMP

Part of: mitochondrial inner membrane (GO:0005743)

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

Taxonomic distribution

• NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding-yeast mitochondria contain an inner-membrane peptidase complex whose Imp1 and Som1 proteins physically interact. [DOI:10.1007/s004380051192]

Canonical examples

• NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model used to identify Som1 as a third IMP peptidase-complex subunit alongside Imp1 and Imp2. [DOI:10.1007/s004380051192]

Functions

• mitochondrial protein processing GO:0034982 — IMP contributes to mitochondrial protein processing by cleaving inner-membrane protease substrates that are targeted to the intermembrane space.
  • GO:0042720 GO:0042720 defines IMP as an inner-membrane protease complex for nuclear- and mitochondrially encoded proteins targeted to the intermembrane space.
  • GO:0034982 GO:0034982 denotes peptide cleavage of mitochondrial proteins, including cleavage contributing to import.
  • DOI:10.1016/s0167-4889(02)00265-3 Gakh et al. 2002 reviewed inner membrane peptidase as one of the conserved mitochondrial peptidases that processes specific precursor-polypeptide subsets.

Mechanism graphs

IMP supports inner-membrane proteolytic processing (FUNCTION)

IMP resides at the mitochondrial inner membrane and cleaves selected imported and mitochondrially encoded substrates that are targeted to the intermembrane space.

Discussions

• CURATION_TODO (OPEN): Resolve exact source-neutral Imp1, Imp2, and Som1 family groundings before adding IMP component rows. GO exactly grounds the IMP complex and Jan et al. identify Som1 as a third budding-yeast subunit, but this first record leaves Imp1, Imp2, and Som1 rows unasserted until exact taxon-agnostic family identifiers are verified.

Evidence

• GO:0042720 Gene Ontology cellular-component term for the mitochondrial inner membrane peptidase complex.
• GO:0098800 Gene Ontology cellular-component parent term for inner mitochondrial membrane protein complexes.
• GO:1905370 Gene Ontology cellular-component parent term for serine-type endopeptidase complexes.
• GO:0005743 Gene Ontology cellular-component term for the mitochondrial inner membrane that contains IMP.
• GO:0034982 Gene Ontology biological-process term for mitochondrial protein processing.
• DOI:10.1007/s004380051192 Jan et al. 2000, 'Som1, a third component of the yeast mitochondrial inner membrane peptidase complex that contains Imp1 and Imp2', Molecular and General Genetics.
• DOI:10.1016/s0167-4889(02)00265-3 Gakh et al. 2002, 'Mitochondrial processing peptidases', Biochimica et Biophysica Acta.

Curation history

• 2026-09-18T18:35:42Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
• 2026-09-18T18:36:29Z codex · EXPANDED_RECORD — Added GO synonymy, inner-mitochondrial-membrane and serine-type endopeptidase parentage, mitochondrial-inner-membrane parthood, Saccharomyces scope, mitochondrial-protein-processing evidence, a nonmechanistic IMP processing graph, and an IMP subunit-boundary TODO.
• 2026-09-18T18:47:20Z codex · ADDRESS_REVIEW — Resolved #1181 by removing the after-import qualifier from the IMP function description so it does not exclude mitochondrially encoded substrates.

Source: data/structures/other/mitochondrial_inner_membrane_peptidase_complex.yaml