proteasome complex

GO:0000502 · Other · Multiprotein complex · Proposed

A large multisubunit complex which catalyzes protein degradation, found in eukaryotes, archaea and some bacteria. In eukaryotes, this complex consists of the barrel shaped proteasome core complex and one or two associated proteins or complexes that act in regulating entry into or exit from the core. [GO:0000502]

Synonyms: proteasome; 26S proteasome

Has part: proteasome core complex (GO:0005839); proteasome accessory complex (GO:0022624)

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
proteasome core complex	Protein complex	part of	`GO:0005839`			ESSENTIAL	Barrel-shaped 20S proteolytic core that sequesters active sites in an internal chamber. `GO:0005839` GO:0005839 identifies the proteasome core complex as the barrel-shaped proteolytic core. `DOI:10.1146/annurev-biochem-060410-150257` Tomko and Hochstrasser 2013 review the eukaryotic 26S proteasome as a 20S core particle capped by a 19S regulatory particle.
proteasome accessory complex	Protein complex	part of	`GO:0022624`			UNKNOWN	Caps or regulators that bind the 20S core and control protein entry into, or exit from, the proteolytic core complex. `GO:0022624` GO:0022624 defines proteasome accessory complexes as caps on one or both ends of the core that regulate entry or exit. `DOI:10.3389/fmolb.2019.00023` Muller and Weber-Ban 2019 review bacterial regulator complexes that associate with the 20S core particle to recruit and internalize substrates.

Taxonomic distribution

NCBITaxon:2157 Archaea — COMMON: Archaeal proteasome systems combine 20S cores with proteasome-associated ATPases such as PAN. [DOI:10.1042/ETLS20180025]
NCBITaxon:201174 Actinomycetota — VARIABLE: Bacterial proteasomes occur in mycobacteria and other actinobacteria, where 20S cores pair with regulators such as Mpa, Bpa, or Cpa. [DOI:10.3389/fmolb.2019.00023]
NCBITaxon:2759 Eukaryota — COMMON: Eukaryotic ubiquitin-proteasome degradation is carried out by 26S proteasomes built from 20S core particles and 19S regulatory particles. [DOI:10.1146/annurev-biochem-060410-150257]

Canonical examples

NCBITaxon:83332 Mycobacterium tuberculosis H37Rv — Actinobacterial model whose 20S proteasome core and Mpa/Bpa regulator routes anchor bacterial proteasome-complex studies. [DOI:10.3389/fmolb.2019.00023]

Functions

proteasomal protein catabolic process GO:0010498 — Proteasome complexes couple regulated substrate access through accessory complexes to proteolysis in the 20S core.
- GO:0000502 The GO graph asserts GO:0010498 has_participant GO:0000502, connecting the proteasome complex to proteasomal protein catabolism.
- DOI:10.1042/ETLS20180025 Maupin-Furlow 2018 reviews archaeal targeted proteolysis by proteasomes associated with AAA-ATPase networks.
- DOI:10.3389/fmolb.2019.00023 Muller and Weber-Ban 2019 review bacterial proteasomal degradation routes that combine the 20S core with alternative regulator complexes.

Mechanism graphs

Accessory complexes regulate access to the proteasome core (FUNCTION)

The proteasome core and accessory complexes form a modular proteasome; accessory complexes regulate substrate access to the core, whose internal active sites degrade protein substrates to peptides.

Subject	Predicate	Object	Evidence
proteasome core complex	is part of	proteasome complex	`GO:0005839` The GO graph asserts that GO:0005839 part_of GO:0000502.
proteasome accessory complex	cap	proteasome core complex	`GO:0022624` GO:0022624 defines proteasome accessory complexes as complexes that cap one or both ends of the core.
proteasome accessory complex	regulate substrate access to	proteasome core complex	`DOI:10.3389/fmolb.2019.00023` Muller and Weber-Ban 2019 review bacterial 20S cores that associate with regulator complexes to recruit and internalize substrates. `DOI:10.1146/annurev-biochem-060410-150257` Tomko and Hochstrasser 2013 review the 19S regulatory particle as the eukaryotic cap that recognizes, deubiquitylates, unfolds, and translocates substrates into the 20S core.
proteasome core complex	degrades	substrate protein	`DOI:10.1042/ETLS20180025` Maupin-Furlow 2018 reviews archaeal 20S proteasomes as intracellular self-compartmentalized proteases.
substrate protein	is converted to	peptide products	`DOI:10.3389/fmolb.2019.00023` Muller and Weber-Ban 2019 review bacterial proteasomal degradation of proteins by regulator-bound 20S core particles.
proteasome complex	carries out	proteasomal protein catabolic process	`GO:0000502` The GO graph asserts GO:0010498 has_participant GO:0000502.

Evidence

GO:0000502 Gene Ontology cellular-component term for the proteasome complex.
GO:0140535 Gene Ontology cellular-component parent for intracellular protein-containing complexes.
GO:1905369 Gene Ontology cellular-component parent for endopeptidase complexes.
GO:0005839 Gene Ontology cellular-component term for the proteasome core complex.
GO:0022624 Gene Ontology cellular-component term for the proteasome accessory complex.
DOI:10.1042/ETLS20180025 Maupin-Furlow 2018, Proteolytic systems of archaea: slicing, dicing, and mincing in the extreme, Emerging Topics in Life Sciences.
DOI:10.3389/fmolb.2019.00023 Muller and Weber-Ban 2019, The bacterial proteasome at the core of diverse degradation pathways, Frontiers in Molecular Biosciences.
DOI:10.1146/annurev-biochem-060410-150257 Tomko and Hochstrasser 2013, Molecular Architecture and Assembly of the Eukaryotic Proteasome, Annual Review of Biochemistry.

Curation history

2026-09-15T11:48:22Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-15T11:51:00Z codex · EXPANDED_RECORD — Added GO parentage, 20S core and accessory-complex parts and components, GO synonyms, archaeal/actinobacterial/eukaryotic scope, an M. tuberculosis example, proteasomal catabolism function, record evidence, and an accessory-capped core proteolysis graph.
2026-09-15T11:51:40Z codex · NORMALIZED_GO_LABEL — Renamed the GO:0022624 accessory-complex component and graph node to the exact GO label.
2026-09-15T12:10:17Z codex · REVIEW_FIXES — Addressed PR #971 review issues #972 and #973 by narrowing the GO:0010498 evidence notes to the proteasomal-protein-catabolism has-participant edge and retargeting accessory-complex substrate access to the proteasome core.

Source: data/structures/other/proteasome_complex.yaml