ADA complex

GO:0140671 · Other · Multiprotein complex · Proposed

A chromatin remodeling complex that regulates transcription via acetylation primarily of nucleosomal histones H3 and H2B. In budding yeast shares the histone acetylation (HAT) module of ADA2-GCN5-NGG1-SGF29 with the related SAGA complex. [GO:0140671]

Synonyms: ADA HAT complex; ADA histone acetyltransferase complex; Ada2/Gcn5/Ada3 transcription activator complex; scADA

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

Components

Component	Type	Part of / acts on	Grounding	Genes	Essential	Role
Ada2 ADA HAT subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ADA2	UNKNOWN	Shared Gcn5 HAT-module constituent of the budding-yeast ADA complex. `GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ada2 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Gcn5 ADA catalytic subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	GCN5	UNKNOWN	Catalytic histone acetyltransferase constituent of the budding-yeast ADA complex. `GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Gcn5 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Ada3/Ngg1 ADA HAT subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NGG1	UNKNOWN	Shared HAT-module constituent of the budding-yeast ADA complex. `GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ada3/Ngg1 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Sgf29 ADA HAT subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	SGF29	UNKNOWN	Shared Gcn5 HAT-module constituent of the budding-yeast ADA complex. `GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 characterized Sgf29 as a HAT/Core-module component of all Gcn5 histone acetyltransferase complexes.
Ahc1 ADA-module subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	AHC1	UNKNOWN	ADA-specific module constituent of the budding-yeast ADA complex. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ahc1 with Ahc2 as the ADA-specific module of the Saccharomyces cerevisiae ADA complex.
Ahc2 ADA-module subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	AHC2	UNKNOWN	ADA-specific module constituent of the budding-yeast ADA complex. `DOI:10.1038/msb.2011.40` Lee et al. 2011 identified Ycr082w/Ahc2 as a novel ADA-complex subunit that co-purified with Ada3, Ahc1, Gcn5, Ada2 and Sgf29.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the organism in which Lee et al. 2011 characterized the six-subunit ADA complex. [DOI:10.1038/msb.2011.40]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Lee et al. 2011 used Saccharomyces cerevisiae TAP-tag affinity purifications and deletion strains to model the ADA complex with the ADA-specific Ahc1/Ahc2 module and the shared Gcn5 HAT module. [DOI:10.1038/msb.2011.40]

Functions

histone acetyltransferase activity GO:0004402 — The ADA complex acetylates nucleosomal histones through its Gcn5 catalytic subunit and the shared Ada2/Ada3/Sgf29 HAT module.
- GO:0140671 GO:0140671 defines the ADA complex as regulating transcription by acetylating primarily nucleosomal histones H3 and H2B.
- GO:0004402 GO:0004402 is the Gene Ontology molecular-function term for histone acetyltransferase activity.
- DOI:10.1038/msb.2011.40 Lee et al. 2011 treated ADA as one of the budding-yeast Gcn5 histone acetyltransferase complexes.

Mechanism graphs

ADA carries yeast histone acetyltransferase activity (FUNCTION)

In Saccharomyces cerevisiae, the Ahc1/Ahc2 ADA-specific module and the shared Gcn5 HAT module form the ADA complex.

Subject	Predicate	Object	Evidence
Ada2 ADA HAT subunit	contributes to	ADA complex	`GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ada2 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Gcn5 ADA catalytic subunit	contributes to	ADA complex	`GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Gcn5 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Ada3/Ngg1 ADA HAT subunit	contributes to	ADA complex	`GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ada3/Ngg1 as a HAT/Core-module constituent of the Saccharomyces cerevisiae ADA complex.
Sgf29 ADA HAT subunit	contributes to	ADA complex	`GO:0140671` GO:0140671 defines the ADA complex as sharing the ADA2-GCN5-NGG1-SGF29 HAT module with SAGA in budding yeast. `DOI:10.1038/msb.2011.40` Lee et al. 2011 characterized Sgf29 as a HAT/Core-module component of all Gcn5 histone acetyltransferase complexes.
Ahc1 ADA-module subunit	contributes to	ADA complex	`DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled Ahc1 with Ahc2 as the ADA-specific module of the Saccharomyces cerevisiae ADA complex.
Ahc2 ADA-module subunit	contributes to	ADA complex	`DOI:10.1038/msb.2011.40` Lee et al. 2011 identified Ycr082w/Ahc2 as a novel ADA-complex subunit that co-purified with Ada3, Ahc1, Gcn5, Ada2 and Sgf29.
ADA complex	supports	histone acetyltransferase activity	`GO:0140671` GO:0140671 defines ADA as a chromatin-remodeling complex that acetylates nucleosomal histones. `GO:0004402` GO:0004402 is the molecular-function term for histone acetyltransferase activity. `DOI:10.1038/msb.2011.40` Lee et al. 2011 modeled ADA as a budding-yeast Gcn5 HAT complex.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the ADA-complex constituents. GO:0140671 and Lee et al. 2011 define the budding-yeast ADA complex subunits. Exact source-neutral InterPro, Pfam, NCBIfam or UniProt family boundaries for these ADA subunit classes need narrower curation before the component labels can be grounded.
INTERPRETATION (RESOLVED): Do not copy GO:0140671's PMID:28966424 definition xref into record evidence. QuickGO currently lists PMID:28966424 among GO:0140671 definition xrefs, but NCBI E-utilities resolves that PMID to an unrelated 2016 Personality and Individual Differences article on social anxiety in combat veterans.

Evidence

GO:0140671 Gene Ontology cellular-component term for the ADA complex, including ADA HAT complex and ADA histone acetyltransferase complex exact synonyms.
GO:0070461 Gene Ontology cellular-component parent term for SAGA-type histone acetyltransferase complexes.
GO:0004402 Gene Ontology molecular-function term for histone acetyltransferase activity.
PMID:21734642 PubMed identifier for Lee et al. 2011, the budding-yeast SAGA and ADA architecture paper cited by GO:0140671.
DOI:10.1038/msb.2011.40 DOI for Lee et al. 2011, 'Combinatorial depletion analysis to assemble the network architecture of the SAGA and ADA chromatin remodeling complexes', verified through NCBI E-utilities.

Curation history

2026-09-27T06:45:17Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-27T06:47:08Z codex · EXPANDED_RECORD — Added ADA exact and related synonymy, SAGA-type parentage, six budding-yeast ADA constituent rows, yeast scope, histone acetyltransferase activity, GO/PubMed/DOI evidence, a nonmechanistic function graph, an ADA subunit-grounding TODO, and an explanation for excluding the unrelated GO definition xref PMID:28966424.
2026-09-27T06:47:40Z codex · CLEANED_YAML_ALIASES — Deep-copied ADA graph-edge evidence lists so the record serializes without YAML anchors or aliases.

Source: data/structures/other/ada_complex.yaml