Gcn5-containing histone acetyltransferase complexes in Drosophila melanogaster

The histone acetyltransferase Gcn5 acetylates histone H3 as the catalytic subunit of several coactivator complexes. Gcn5 always sits in a HAT module with Ada3, Sgf29 and an Ada2 paralog. With Ada2b it forms part of SAGA, a large coactivator that also contains a TBP-interacting core, the Tra1 homolog Nipped-A, and a deubiquitinase module that removes ubiquitin from histone H2B through the protease Nonstop. With Ada2a it forms ATAC, which also contains the Atac1-3 subunits. Smaller ADA and CHAT (Chiffon-containing) complexes contain only the HAT module, with Chiffon in CHAT.

MODULE:dmel_gcn5_acetyltransferase_complexesDRAFTCONCRETEProtein Complexmodules/dmel_gcn5_acetyltransferase_complexes.yaml
histone acetyltransferase complexGO:0000123
FB:FBgg0001748
FlyBase gene group GCN5: Gcn5-containing complexes
FlyBase release FB2026_03 groups 32 D. melanogaster genes as gcn5-containing complexes (GCN5); this module models that group.
GO:0000123
histone acetyltransferase complex
GO term grounding the module as histone acetyltransferase complex.

The four FlyBase subgroups are modelled as alternative complexes, so shared HAT-module subunits appear in each. SAGA is decomposed into its HAT, deubiquitinase, core, Tra1 and SF3B parts; within the core, assignment of the two Ada1 paralogs and Wda follows their FlyBase membership of SAGA and is not meant to resolve finer architecture. ATAC also contains Hcf, Wds, Chrac-14, NC2beta and Mocs2B as listed by FlyBase. FlyBase groups realized by this module: GCN5 (FBgg0001748). Subgroups folded into it: ATAC, SAGA, ADAC, CHAT. Participants were generated from the FlyBase gene-group membership and mapped to UniProtKB by projects/FLYBASE_GENE_GROUPS/generate_modules.py from module_specs/dmel_gcn5_acetyltransferase_complexes.yaml. None of the member genes has a gene review in this repository yet.

10Nodes
5Parts
1Variant Sets
4Variants
8Annotons
0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_gcn5_acetyltransferase_complexes deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Function consistency and core coverage

0 gene-function check(s) reflected in core functions · 0 conflict(s) · 5 evidence or coverage gap(s) (5 comparison(s))

Retained noncore functions are reported separately; they do not require promotion to core functions. Support from representative genes does not establish conservation across the whole family. Missing reviews or identifiers leave a claim unverified.

AnnotonParticipantFunctionAssessment
saga_hat_module_complex/gcn5 Gcn5
UniProtKB:Q9VTZ1
Complex Unit
histone acetyltransferase activity
GO:0004402
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
saga_dub_module_complex/not not
UniProtKB:Q9VVR1
Complex Unit
histone H2B deubiquitinase activity
GO:0140936
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
atac_complex/gcn5 Gcn5
UniProtKB:Q9VTZ1
Complex Unit
histone acetyltransferase activity
GO:0004402
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
ada_complex/gcn5 Gcn5
UniProtKB:Q9VTZ1
Complex Unit
histone acetyltransferase activity
GO:0004402
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
chat_complex/gcn5 Gcn5
UniProtKB:Q9VTZ1
Complex Unit
histone acetyltransferase activity
GO:0004402
Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.

Gene-review completeness (0/32 grounded genes reviewed)

0 complete review(s) · 0 with deep research · 32 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
Atac3 M9NFF9 ✗ — —
Ada3 M9PHZ1 ✗ — —
Taf12 P49905 ✗ — —
Taf9 Q27272 ✗ — —
Ada2a Q7KSD8 ✗ — —
Nipped-A Q8I8U7 ✗ — —
Ada2b Q8I8V0 ✗ — —
Ada1-1 Q8IP99 ✗ — —
Ada1-2 Q8IPA1 ✗ — —
chif Q9NK54 ✗ — —
wds Q9V3J8 ✗ — —
Chrac-14 Q9V444 ✗ — —
Hcf Q9V4C8 ✗ — —
Mocs2B Q9VBX2 ✗ — —
wda Q9VCN9 ✗ — —
Spt3 Q9VGE2 ✗ — —
Sf3b5 Q9VHI4 ✗ — —
Atac2 Q9VJ73 ✗ — —
NC2beta Q9VJQ5 ✗ — —
Yeats2 Q9VLL1 ✗ — —
Atac1 Q9VM59 ✗ — —
Saf6 Q9VPT4 ✗ — —
Atxn7 Q9VQB6 ✗ — —
Gcn5 Q9VTZ1 ✗ — —
Spt20 Q9VU86 ✗ — —
not Q9VVR1 ✗ — —
Sgf11 Q9VVR6 ✗ — —
Spt7 Q9VX12 ✗ — —
e(y)2 Q9VYX1 ✗ — —
Sf3b3 Q9W0M7 ✗ — —
Sgf29 Q9W2I4 ✗ — —
Taf10b Q9XZT7 ✗ — —

Details

Context
Drosophila melanogasterNCBITaxon:7227
chromatinGO:0000785
Gcn5 acetyltransferase complexesProtein Complexdmel_gcn5_acetyltransferase_complexes

SAGA, ATAC, ADA and CHAT coactivator complexes that share the Gcn5 histone acetyltransferase module.

histone acetyltransferase complexGO:0000123
Context
Drosophila melanogasterNCBITaxon:7227
chromatinGO:0000785
Variant set: Gcn5-containing complexes (One Or More)
SAGA complexProtein Complexsaga
SAGA complexGO:0000124
Part 1: histone H3 acetylation
SAGA HAT moduleProtein Complexsaga_hat_module

Annotons

SAGA HAT module
saga_hat_module_complex
Participant: Protein Complex: SAGA HAT module
Protein Complex:
SAGA HAT module
Active units:
Gcn5
Participant: Gene Product: Gcn5
Gene Product:
Function:
histone acetyltransferase activityGO:0004402
Ada2b
Participant: Gene Product: Ada2b
Gene Product:
Ada3
Participant: Gene Product: Ada3
Gene Product:
Sgf29
Participant: Gene Product: Sgf29
Gene Product:
Part 2: histone H2B deubiquitylation
SAGA deubiquitinase moduleProtein Complexsaga_dub_module

Annotons

SAGA deubiquitinase module
saga_dub_module_complex
Participant: Protein Complex: SAGA deubiquitinase module
Protein Complex:
SAGA deubiquitinase moduleGO:0071819
Active units:
not
Participant: Gene Product: not
Gene Product:
Function:
histone H2B deubiquitinase activityGO:0140936
Sgf11
Participant: Gene Product: Sgf11
Gene Product:
e(y)2
Participant: Gene Product: e(y)2
Gene Product:
Atxn7
Participant: Gene Product: Atxn7
Gene Product:
Part 3: structural core and TBP interaction
SAGA core moduleProtein Complexsaga_core_module

Annotons

SAGA core module
saga_core_module_complex
Participant: Protein Complex: SAGA core module
Protein Complex:
SAGA core module
Active units:
Taf9
Participant: Gene Product: Taf9
Gene Product:
Taf10b
Participant: Gene Product: Taf10b
Gene Product:
Taf12
Participant: Gene Product: Taf12
Gene Product:
Saf6
Participant: Gene Product: Saf6
Gene Product:
Spt3
Participant: Gene Product: Spt3
Gene Product:
Spt7
Participant: Gene Product: Spt7
Gene Product:
Spt20
Participant: Gene Product: Spt20
Gene Product:
Ada1-1
Participant: Gene Product: Ada1-1
Gene Product:
Ada1-2
Participant: Gene Product: Ada1-2
Gene Product:
wda
Participant: Gene Product: wda
Gene Product:
Part 4: activator-interacting subunit
Nipped-A (Tra1)Protein Complexsaga_tra1

Annotons

Nipped-A Nipped-A (Tra1)
saga_tra1_nipped_a
Participant: Gene Product: Nipped-A
Gene Product:
Part 5: splicing-factor subunits
SF3B subunits associated with SAGAProtein Complexsaga_splicing_factors

Annotons

SF3B subunits associated with SAGA
saga_splicing_factors_complex
Participant: Protein Complex: SF3B subunits associated with SAGA
Protein Complex:
SF3B subunits associated with SAGA
Active units:
Sf3b3
Participant: Gene Product: Sf3b3
Gene Product:
Sf3b5
Participant: Gene Product: Sf3b5
Gene Product:
ATAC complexProtein Complexatac

Annotons

ATAC complex
atac_complex
Participant: Protein Complex: ATAC complex
Protein Complex:
ATAC complexGO:0140672
Active units:
Ada2a
Participant: Gene Product: Ada2a
Gene Product:
Ada3
Participant: Gene Product: Ada3
Gene Product:
Atac1
Participant: Gene Product: Atac1
Gene Product:
Atac2
Participant: Gene Product: Atac2
Gene Product:
Atac3
Participant: Gene Product: Atac3
Gene Product:
Chrac-14
Participant: Gene Product: Chrac-14
Gene Product:
Gcn5
Participant: Gene Product: Gcn5
Gene Product:
Function:
histone acetyltransferase activityGO:0004402
Hcf
Participant: Gene Product: Hcf
Gene Product:
Mocs2B
Participant: Gene Product: Mocs2B
Gene Product:
NC2beta
Participant: Gene Product: NC2beta
Gene Product:
Sgf29
Participant: Gene Product: Sgf29
Gene Product:
Yeats2
Participant: Gene Product: Yeats2
Gene Product:
wds
Participant: Gene Product: wds
Gene Product:
ADA complexProtein Complexada

Annotons

ADA complex
ada_complex
Participant: Protein Complex: ADA complex
Protein Complex:
ADA complexGO:0140671
Active units:
Ada2b
Participant: Gene Product: Ada2b
Gene Product:
Ada3
Participant: Gene Product: Ada3
Gene Product:
Gcn5
Participant: Gene Product: Gcn5
Gene Product:
Function:
histone acetyltransferase activityGO:0004402
Sgf29
Participant: Gene Product: Sgf29
Gene Product:
CHAT complexProtein Complexchat

Annotons

CHAT complex
chat_complex
Participant: Protein Complex: CHAT complex
Protein Complex:
CHAT complex
Active units:
Ada2b
Participant: Gene Product: Ada2b
Gene Product:
Ada3
Participant: Gene Product: Ada3
Gene Product:
Gcn5
Participant: Gene Product: Gcn5
Gene Product:
Function:
histone acetyltransferase activityGO:0004402
Sgf29
Participant: Gene Product: Sgf29
Gene Product:
chif
Participant: Gene Product: chif
Gene Product: