U5 snRNP

GO:0005682 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A ribonucleoprotein complex that contains small nuclear RNA U5, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U5 snRNP, most of which remain associated with the U5 snRNA both while the U5 snRNP is free or assembled into a series of spliceosomal complexes. [GO:0005682]

Synonyms: snRNP U5

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
U5 snRNA	Rna	part of	`SO:0000395`				U5 small nuclear RNA constituent named in the U5 snRNP definition and grounded to the U5 snRNA Sequence Ontology term. `GO:0005682` GO:0005682 defines the U5 snRNP as containing small nuclear RNA U5. `SO:0000395` SO:0000395 is the Sequence Ontology term for U5 snRNA.
Sm protein ring	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Heptameric Sm protein ring associated with U5 snRNA in the U5 snRNP. `GO:0005682` GO:0005682 defines the U5 snRNP as containing a heptameric ring of Sm proteins.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: The U5 snRNP subcomplex is represented in budding-yeast U4/U6.U5 tri-snRNP cryo-EM structures; broader eukaryotic distribution is left for follow-up curation. [DOI:10.1038/nature16940]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model whose U5 snRNA and associated U5 snRNP proteins were resolved inside U4/U6.U5 tri-snRNP cryo-EM structures. [DOI:10.1038/nature16940]

Mechanism graphs

U5 snRNA and the Sm ring are U5 snRNP constituents (ASSEMBLY)

The U5 snRNP contains U5 small nuclear RNA and a heptameric Sm protein ring; GO:0005682 also names additional U5-specific proteins whose exact family boundaries remain to be resolved.

Subject	Predicate	Object	Evidence
U5 snRNA	contributes constituents to	U5 snRNP	`GO:0005682` GO:0005682 defines the U5 snRNP as containing small nuclear RNA U5.
Sm protein ring	contributes constituents to	U5 snRNP	`GO:0005682` GO:0005682 defines the U5 snRNP as containing a heptameric ring of Sm proteins.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral groundings for the Sm ring, Prp8, Brr2, Snu114, Prp6 and other U5-specific protein families that form the U5 snRNP. The first GO:0005682 record captures U5 snRNA and the GO-defined Sm ring at coarse granularity. Individual spliceosomal Sm proteins and U5-specific protein-family boundaries should be resolved before splitting this inventory.

Evidence

GO:0005682 Gene Ontology cellular-component term for the U5 snRNP and its exact synonym.
GO:0097525 Gene Ontology cellular-component parent term for spliceosomal snRNP complex.
SO:0000395 Sequence Ontology term for U5 snRNA.
DOI:10.1038/nature14548 Nguyen, Galej, Bai and colleagues 2015, The architecture of the spliceosomal U4/U6.U5 tri-snRNP, Nature.
PMID:26106855 PubMed identifier for Nguyen, Galej, Bai and colleagues 2015 as reported by PubMed.
DOI:10.1038/nature16940 Nguyen, Galej, Bai and colleagues 2016, Cryo-EM structure of the yeast U4/U6.U5 tri-snRNP at 3.7 Angstrom resolution, Nature.
PMID:26829225 PubMed identifier for Nguyen, Galej, Bai and colleagues 2016 as reported by PubMed.

Curation history

2026-09-24T14:38:41Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-24T14:39:59Z codex · EXPANDED_RECORD — Added the GO exact synonym, spliceosomal snRNP parentage, U5 snRNA and Sm-ring components, budding-yeast distribution, Nguyen/Galej/Nagai yeast U4/U6.U5 tri-snRNP cryo-EM evidence, a minimal U5 snRNP constituent graph and a protein-component grounding TODO.
2026-09-24T14:51:49Z codex · ADDRESS_REVIEW — #1498: reworded the U5 graph so U5 snRNA and Sm ring constituents are explicitly partial; #1499: narrowed the U5 snRNA component role to its GO containment and SO grounding.

Source: data/structures/ribonucleoprotein/u5_snrnp.yaml