nucleolar ribonuclease P complex

GO:0005655 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A ribonuclease P complex located in the nucleolus of a eukaryotic cell, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. Eukaryotic nucleolar ribonuclease P complexes generally contain a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules. [GO:0005655]

Synonyms: nucleolar RNase P complex

Part of: nucleolus (GO:0005730)

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
RNase P RNA	Rna	part of	`SO:0000386`				Single RNA constituent of eukaryotic nucleolar RNase P complexes that is necessary but not sufficient for catalysis. `GO:0005655` GO:0005655 defines nucleolar ribonuclease P complexes as generally containing a single necessary RNA molecule. `SO:0000386` SO:0000386 is the Sequence Ontology term for RNase_P_RNA.
nucleolar RNase P protein subunits	Protein	part of	Reviewed label only (reviewed name; no accession asserted)				Protein constituents that accompany RNase P RNA in eukaryotic nucleolar RNase P complexes. `GO:0005655` GO:0005655 defines nucleolar ribonuclease P complexes as generally containing several protein molecules.

Functions

ribonuclease P activity GO:0004526 — The nucleolar ribonuclease P complex removes 5-prime extra nucleotides from precursor tRNA by endonucleolytic RNA cleavage.
- GO:0004526 GO:0004526 is the Gene Ontology molecular-function term for ribonuclease P activity.
- GO:0005655 GO:0005655 defines nucleolar RNase P as catalyzing 5-prime endonucleolytic cleavage of precursor tRNAs.
tRNA 5'-leader removal GO:0001682 — Nucleolar RNase P complexes generate mature tRNA 5-prime ends by cleaving 5-prime leader sequences from pre-tRNAs.
- GO:0001682 GO:0001682 is the Gene Ontology biological-process term for tRNA 5'-leader removal.
- GO:0005655 GO:0005655 defines nucleolar RNase P as generating mature tRNAs by precursor-tRNA cleavage.

Mechanism graphs

RNase P RNA and proteins form nucleolar RNase P (ASSEMBLY)

Eukaryotic nucleolar ribonuclease P complexes generally contain a single RNase P RNA and several protein molecules.

Subject	Predicate	Object	Evidence
RNase P RNA	contributes constituents to	nucleolar ribonuclease P complex	`GO:0005655` GO:0005655 defines the complex as generally containing a single RNA molecule.
nucleolar RNase P protein subunits	contributes constituents to	nucleolar ribonuclease P complex	`GO:0005655` GO:0005655 defines the complex as generally containing several protein molecules.
nucleolar ribonuclease P complex	localizes to	nucleolus	`GO:0005655` GO:0005655 defines this RNase P complex by its nucleolar localization. `GO:0005730` GO:0005730 is the nucleolus cellular-component term.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral protein-family boundaries for eukaryotic nucleolar RNase P complexes. The first GO:0005655 record captures the GO-defined single-RNA, several-protein nucleolar composition at cohort granularity. Exact source-neutral nuclear RNase P protein families should be resolved before assigning protein groundings.

Evidence

GO:0005655 Gene Ontology cellular-component term for the nucleolar ribonuclease P complex and its exact synonym.
GO:0030681 Gene Ontology cellular-component parent term for multimeric ribonuclease P complexes.
GO:0140513 Gene Ontology cellular-component parent term for nuclear protein-containing complexes.
GO:0005730 Gene Ontology cellular-component term for the nucleolus.
SO:0000386 Sequence Ontology term for RNase_P_RNA.
GO:0004526 Gene Ontology molecular-function term for ribonuclease P activity.
GO:0001682 Gene Ontology biological-process term for tRNA 5'-leader removal.

Curation history

2026-09-25T12:56:06Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T12:56:55Z codex · EXPANDED_RECORD — Added nucleolar RNase P parentage and parthood, GO exact synonymy, SO-grounded RNase P RNA plus reviewed-label-only nucleolar RNase P protein components, conservative function terms, an assembly graph and a TODO for exact eukaryotic protein-family boundaries.

Source: data/structures/ribonucleoprotein/nucleolar_ribonuclease_p_complex.yaml