SMC5/6 complex in Drosophila melanogaster

The SMC5/6 complex is the third eukaryotic SMC complex, acting in DNA repair by homologous recombination, in the resolution of recombination and replication intermediates, and in the maintenance of repetitive DNA such as the rDNA and heterochromatin. It is built on an SMC5-SMC6 heterodimer bridged by the kleisin Nse4, which binds the Nse1-Nse3 pair (Nse3 is a MAGE-family protein, encoded in Drosophila by MAGE). The SUMO ligase subunit Nse2 binds the SMC arms. Drosophila has two Nse2 paralogs, Quijote (qjt) and Cervantes (cerv), which define two variants of the complex.

MODULE:dmel_smc5_6_complexDRAFTCONCRETEProtein Complexmodules/dmel_smc5_6_complex.yaml
Smc5-Smc6 complexGO:0030915
FB:FBgg0000060
FlyBase gene group SMC5-6-T: Smc5/6 complex - qjt variant
FlyBase release FB2026_03 groups 6 D. melanogaster genes as smc5/6 complex - qjt variant (SMC5-6-T); this module models that group.
FB:FBgg0001825
FlyBase gene group SMC5-6-V: Smc5/6 complex - cerv variant
FlyBase release FB2026_03 groups 6 D. melanogaster genes as smc5/6 complex - cerv variant (SMC5-6-V); this module models that group.
GO:0030915
Smc5-Smc6 complex
GO term grounding the module as Smc5-Smc6 complex.

FlyBase defines the QJT and CERV variants (SMC5-6-T, SMC5-6-V) that differ only in the Nse2 paralog; the shared subunits are modelled once. SUMO ligase activity is not assigned to Qjt or Cerv because it is inferred from yeast and human Nse2 rather than shown for the fly proteins; for the same reason the ubiquitin ligase activity inferred for Nse1 (ISS) is not assigned. The SMC subunits are given ATP hydrolysis activity (GO:0016887), which they carry in GOA (ISS, NAS, IEA); their ATPase heads, engaged across the heterodimer, drive the complex. GO has a complex-level term for SMC-complex DNA entrapment (GO:0061776 ATP-dependent topological DNA co-entrapment activity, used by PomBase for the fission yeast complexes), but it is not annotated to the Drosophila proteins and is not asserted here. FlyBase groups realized by this module: SMC5-6-T (FBgg0000060), SMC5-6-V (FBgg0001825). 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_smc5_6_complex.yaml. None of the member genes has a gene review in this repository yet.

6Nodes
3Parts
1Variant Sets
2Variants
4Annotons
0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_smc5_6_complex 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) · 2 evidence or coverage gap(s) (2 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
smc5_smc6_complex/smc5 SMC5
UniProtKB:Q8IPT2
Complex Unit 		ATP hydrolysis activity
GO:0016887 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
smc5_smc6_complex/smc6 SMC6
UniProtKB:Q9VCB8
Complex Unit 		ATP hydrolysis activity
GO:0016887 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.

Gene-review completeness (0/7 grounded genes reviewed)

0 complete review(s) · 0 with deep research · 7 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
SMC5 Q8IPT2 ✗ — —
MAGE Q9I7L4 ✗ — —
SMC6 Q9VCB8 ✗ — —
Nse4 Q9VKV4 ✗ — —
Nse1 Q9VMA0 ✗ — —
qjt Q9VVH7 ✗ — —
cerv Q9VXT3 ✗ — —

Details

Context
Drosophila melanogasterNCBITaxon:7227
nucleusGO:0005634
SMC5/6 complexProtein Complexdmel_smc5_6_complex

SMC5-SMC6 heterodimer with Nse1-MAGE-Nse4 and one of two Nse2 SUMO ligase paralogs (Qjt or Cerv).

Smc5-Smc6 complexGO:0030915
Context
Drosophila melanogasterNCBITaxon:7227
nucleusGO:0005634
Part 1: SMC ATPase core
SMC5-SMC6 heterodimerProtein Complexsmc5_smc6

Annotons

SMC5-SMC6 heterodimer
smc5_smc6_complex
Participant: Protein Complex: SMC5-SMC6 heterodimer
Protein Complex:
SMC5-SMC6 heterodimer
Active units:
SMC5
Participant: Gene Product: SMC5
Gene Product:
SMC5UniProtKB:Q8IPT2
Function:
ATP hydrolysis activityGO:0016887
SMC6
Participant: Gene Product: SMC6
Gene Product:
SMC6UniProtKB:Q9VCB8
Function:
ATP hydrolysis activityGO:0016887
Part 2: kleisin and kleisin-associated subunits
Nse1-MAGE-Nse4 subcomplexProtein Complexnse1_nse3_nse4

Annotons

Nse1-MAGE-Nse4 subcomplex
nse1_nse3_nse4_complex
Participant: Protein Complex: Nse1-MAGE-Nse4 subcomplex
Protein Complex:
Nse1-MAGE-Nse4 subcomplex
Active units:
Nse4
Participant: Gene Product: Nse4
Gene Product:
Nse4UniProtKB:Q9VKV4
Nse1
Participant: Gene Product: Nse1
Gene Product:
Nse1UniProtKB:Q9VMA0
MAGE
Participant: Gene Product: MAGE
Gene Product:
MAGEUniProtKB:Q9I7L4
Part 3: SUMO ligase subunit
Nse2 SUMO ligase subunitProtein Complexnse2_sumo_ligase
Variant set: Nse2 paralogs (One Or More)
Quijote (Nse2 paralog)Protein Complexnse2_qjt

Annotons

qjt Quijote (Nse2 paralog)
nse2_qjt_qjt
Participant: Gene Product: qjt
Gene Product:
qjtUniProtKB:Q9VVH7
Cervantes (Nse2 paralog)Protein Complexnse2_cerv

Annotons

cerv Cervantes (Nse2 paralog)
nse2_cerv_cerv
Participant: Gene Product: cerv
Gene Product:
cervUniProtKB:Q9VXT3