Small nucleolar ribonucleoprotein complexes in Drosophila melanogaster

Small nucleolar ribonucleoproteins (snoRNPs) guide chemical modification and processing of ribosomal RNA in the nucleolus. Box H/ACA snoRNPs contain a guide RNA and four core proteins, the pseudouridine synthase dyskerin (Nop60B in Drosophila), Gar1, Nhp2 and Nop10, and convert target uridines into pseudouridine. Box C/D snoRNPs contain the methyltransferase fibrillarin with Nop56, Nop58 and a 15.5K protein and catalyse 2'-O-methylation of target nucleotides. The U3 box C/D snoRNP instead acts in early pre-rRNA cleavage within the small-subunit processome.

MODULE:dmel_small_nucleolar_rnpsDRAFTCONCRETEProtein Complexmodules/dmel_small_nucleolar_rnps.yaml
sno(s)RNA-containing ribonucleoprotein complexGO:0005732
FB:FBgg0001761
FlyBase gene group SRNPS: Small nucleolar ribonucleoprotein complexes
FlyBase release FB2026_03 groups 8 D. melanogaster genes as small nucleolar ribonucleoprotein complexes (SRNPS); this module models that group.
GO:0005732
sno(s)RNA-containing ribonucleoprotein complex
GO term grounding the module as sno(s)RNA-containing ribonucleoprotein complex.

Parts follow FlyBase subgroups H-ACA and C-DRNP. The C/D group includes U3-55K, a U3 snoRNP-specific protein, so the part uses the general box C/D RNP complex term rather than the methylation-guide snoRNP term. The 15.5K core protein of C/D snoRNPs and the snoRNAs themselves are not in the FlyBase groups and are not participants. Nop60B has also been studied as minifly (mfl). FlyBase groups realized by this module: SRNPS (FBgg0001761). Subgroups folded into it: H-ACA, C-DRNP. 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_small_nucleolar_rnps.yaml. None of the member genes has a gene review in this repository yet.

3Nodes
2Parts
0Variant Sets
0Variants
2Annotons
0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_small_nucleolar_rnps 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
h_aca_snornp_complex/nop60b Nop60B
UniProtKB:O44081
Complex Unit 		pseudouridine synthase activity
GO:0009982 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
c_d_snornp_complex/fib Fib
UniProtKB:Q9W1V3
Complex Unit 		rRNA methyltransferase activity
GO:0008649 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.

Gene-review completeness (0/8 grounded genes reviewed)

0 complete review(s) · 0 with deep research · 8 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
U3-55K A1Z9W3 ✗ — —
Nop60B O44081 ✗ — —
Nop56 Q7KS60 ✗ — —
Gar1 Q7KVQ0 ✗ — —
NHP2 Q9V3U2 ✗ — —
Nop10 Q9V5P6 ✗ — —
nop5 Q9VM69 ✗ — —
Fib Q9W1V3 ✗ — —

Details

Context
Drosophila melanogasterNCBITaxon:7227
nucleolusGO:0005730
snoRNPsProtein Complexdmel_small_nucleolar_rnps

Box H/ACA (pseudouridylation) and box C/D (2'-O-methylation) snoRNP protein cores.

sno(s)RNA-containing ribonucleoprotein complexGO:0005732
Context
Drosophila melanogasterNCBITaxon:7227
nucleolusGO:0005730
Part 1: rRNA pseudouridylation
Box H/ACA snoRNP coreProtein Complexh_aca_snornp

Annotons

Box H/ACA snoRNP core
h_aca_snornp_complex
Participant: Protein Complex: Box H/ACA snoRNP core
Protein Complex:
Box H/ACA snoRNP coreGO:0031429
Active units:
Gar1
Participant: Gene Product: Gar1
Gene Product:
Gar1UniProtKB:Q7KVQ0
NHP2
Participant: Gene Product: NHP2
Gene Product:
NHP2UniProtKB:Q9V3U2
Nop10
Participant: Gene Product: Nop10
Gene Product:
Nop10UniProtKB:Q9V5P6
Nop60B
Participant: Gene Product: Nop60B
Gene Product:
Nop60BUniProtKB:O44081
Function:
pseudouridine synthase activityGO:0009982

Processes

rRNA pseudouridine synthesisGO:0031118
Part 2: rRNA 2'-O-methylation and U3-dependent processing
Box C/D snoRNP proteinsProtein Complexc_d_snornp

Annotons

Box C/D snoRNP proteins
c_d_snornp_complex
Participant: Protein Complex: Box C/D snoRNP proteins
Protein Complex:
Box C/D snoRNP proteinsGO:0170049
Active units:
Fib
Participant: Gene Product: Fib
Gene Product:
FibUniProtKB:Q9W1V3
Function:
rRNA methyltransferase activityGO:0008649
Nop56
Participant: Gene Product: Nop56
Gene Product:
Nop56UniProtKB:Q7KS60
U3-55K
Participant: Gene Product: U3-55K
Gene Product:
U3-55KUniProtKB:A1Z9W3
nop5
Participant: Gene Product: nop5
Gene Product:
nop5UniProtKB:Q9VM69

Processes

rRNA 2'-O-methylationGO:0000451