spliceosomal tri-snRNP complex

GO:0097526 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A spliceosomal snRNP complex that is formed by the association of the U4/U6 (or U4atac/U6atac) snRNP with the U5 snRNP. [GO:0097526]

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
U4/U6-family snRNP	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Major- or minor-spliceosome U4/U6-family snRNP subcomplex that associates with U5 snRNP to form a spliceosomal tri-snRNP complex. `GO:0097526` GO:0097526 defines spliceosomal tri-snRNP complexes as formed by association of a U4/U6 or U4atac/U6atac snRNP with U5 snRNP. `GO:0071001` GO:0071001 is the Gene Ontology cellular-component term for the major U4/U6 snRNP. `GO:0071002` GO:0071002 is the Gene Ontology cellular-component term for the minor U4atac/U6atac snRNP.
U5 snRNP	Protein complex	part of	`GO:0005682`				U5 small nuclear ribonucleoprotein subcomplex shared by major and minor spliceosomal tri-snRNP complexes. `GO:0097526` GO:0097526 includes U5 snRNP as the common snRNP partner in spliceosomal tri-snRNP complexes. `GO:0005682` GO:0005682 is the Gene Ontology cellular-component term for the U5 snRNP.

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: The major U4/U6.U5 tri-snRNP is directly evidenced in budding yeast by cryo-electron microscopy; the minor U4atac/U6atac.U5 form is not asserted for budding yeast. [DOI:10.1038/nature16940]
NCBITaxon:9606 Homo sapiens — COMMON: Human U4/U6.U5 and U4atac/U6atac.U5 tri-snRNPs were analyzed biochemically by Schneider, Will, Makarova and colleagues; broader mammalian distribution is left for follow-up curation. [DOI:10.1128/MCB.22.10.3219-3229.2002]

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast major spliceosomal U4/U6.U5 tri-snRNP resolved in the high-resolution cryo-EM structure from Nguyen, Galej, Bai and colleagues. [DOI:10.1038/nature16940]
NCBITaxon:9606 Homo sapiens — Human major and minor spliceosomal tri-snRNPs analyzed in a comparative U4/U6.U5 and U4atac/U6atac.U5 composition study. [DOI:10.1128/MCB.22.10.3219-3229.2002]

Spliceosomal tri-snRNP complexes form when either the major U4/U6 snRNP or the minor U4atac/U6atac snRNP associates with U5 snRNP.

Subject	Predicate	Object	Evidence
U4/U6-family snRNP	contributes to assembly of	spliceosomal tri-snRNP complex	`GO:0097526` GO:0097526 defines the tri-snRNP as formed when U4/U6 or U4atac/U6atac snRNP associates with U5 snRNP.
U5 snRNP	contributes to assembly of	spliceosomal tri-snRNP complex	`GO:0097526` GO:0097526 defines U5 as the shared snRNP partner in spliceosomal tri-snRNP complexes.

CURATION_TODO (OPEN): Keep major and minor spliceosomal tri-snRNP protein inventories resolved on exact child records. The GO:0097526 parent spans two exact subclasses, GO:0046540 for U4/U6 x U5 tri-snRNP and GO:0071009 for U4atac/U6atac x U5 tri-snRNP. Protein-family components and RNA-specific contacts should stay on those child records until a source-neutral component class is available for both subtypes.

GO:0097526 Gene Ontology cellular-component term for spliceosomal tri-snRNP complex.
GO:0097525 Gene Ontology cellular-component parent term for spliceosomal snRNP complex.
GO:0071001 Gene Ontology cellular-component term for the U4/U6 snRNP.
GO:0071002 Gene Ontology cellular-component term for the U4atac/U6atac snRNP.
GO:0005682 Gene Ontology cellular-component term for the U5 snRNP.
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 NCBI E-utilities.
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 NCBI E-utilities.
DOI:10.1128/MCB.22.10.3219-3229.2002 Schneider, Will, Makarova and colleagues 2002, Human U4/U6.U5 and U4atac/U6atac.U5 tri-snRNPs exhibit similar protein compositions, Molecular and Cellular Biology.
PMID:11971955 PubMed identifier for Schneider, Will, Makarova and colleagues 2002 as reported by NCBI E-utilities.

2026-09-25T18:37:24Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T18:38:26Z codex · EXPANDED_RECORD — Added spliceosomal snRNP parentage, a reviewed-label-only U4/U6-family snRNP component, a GO-grounded U5 snRNP component, yeast and human tri-snRNP examples, GO/literature evidence, a nonmechanistic assembly graph and a subtype-boundary TODO.