Mre11 complex

GO:0030870 · Other · Multiprotein complex · Proposed

Trimeric protein complex that possesses endonuclease activity; involved in meiotic recombination, DNA repair and checkpoint signaling. In Saccharomyces cerevisiae, the complex comprises Mre11p, Rad50p, and Xrs2p; complexes identified in other species generally contain proteins orthologous to the Saccharomyces cerevisiae proteins. [GO:0030870]

Synonyms: MRN complex; MRX complex; Rad50 complex; RAD50-MRE11-NBN complex; Rad50-Rad32-Nbs1 complex; RMX complex

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Essential	Role
Mre11 nuclease subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	MRE11	UNKNOWN	Mre11 nuclease-family constituent of the budding-yeast Mre11-Rad50-Xrs2 complex. `GO:0030870` GO:0030870 defines the Saccharomyces cerevisiae Mre11 complex as containing Mre11p, Rad50p and Xrs2p. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied formation of the yeast Mre11-Rad50-Xrs2 complex.
Rad50 ATPase subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	RAD50	UNKNOWN	Rad50 ATPase-family constituent of the budding-yeast Mre11-Rad50-Xrs2 complex. `GO:0030870` GO:0030870 defines the Saccharomyces cerevisiae Mre11 complex as containing Mre11p, Rad50p and Xrs2p. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied formation of the yeast Mre11-Rad50-Xrs2 complex.
Xrs2 regulatory subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	XRS2	UNKNOWN	Xrs2 regulatory constituent of the budding-yeast Mre11-Rad50-Xrs2 complex. `GO:0030870` GO:0030870 defines the Saccharomyces cerevisiae Mre11 complex as containing Mre11p, Rad50p and Xrs2p. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied formation of the yeast Mre11-Rad50-Xrs2 complex.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast has an Mre11-Rad50-Xrs2 complex whose formation is correlated with DNA repair and telomere maintenance. [DOI:10.1093/nar/27.10.2072]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Reference budding-yeast system for Mre11-Rad50-Xrs2 complex formation and homologous recombination-based double-strand-break repair studies. [DOI:10.1093/nar/27.10.2072]

Functions

DNA repair GO:0006281 — The Mre11 complex participates in DNA repair, including homologous recombination-based double-strand-break repair in Saccharomyces cerevisiae.
- GO:0030870 GO:0030870 defines the Mre11 complex as involved in DNA repair.
- GO:0006281 GO:0006281 is the Gene Ontology biological-process term for DNA repair.
- DOI:10.1128/MCB.19.11.7681 Bressan et al. 1999 connected the Mre11-Rad50-Xrs2 complex to homologous recombination-based double-strand-break repair in budding yeast.
reciprocal meiotic recombination GO:0007131 — The Mre11 complex participates in meiotic recombination.
- GO:0030870 GO:0030870 defines the Mre11 complex as involved in meiotic recombination.
- GO:0007131 GO:0007131 is the Gene Ontology biological-process term for reciprocal meiotic recombination.
- DOI:10.1007/s10577-007-1147-9 Borde 2007 reviewed multiple roles of the Mre11 complex for meiotic recombination.

Mechanism graphs

Mre11 supports DNA repair and meiotic recombination (FUNCTION)

The Saccharomyces cerevisiae Mre11, Rad50 and Xrs2 proteins form a trimeric complex that supports DNA repair and meiotic recombination.

Subject	Predicate	Object	Evidence
Mre11 nuclease subunit	contributes to	Mre11 complex	`GO:0030870` GO:0030870 names Mre11p as a constituent of the complex. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied the yeast Mre11-Rad50-Xrs2 complex.
Rad50 ATPase subunit	contributes to	Mre11 complex	`GO:0030870` GO:0030870 names Rad50p as a constituent of the complex. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied the yeast Mre11-Rad50-Xrs2 complex.
Xrs2 regulatory subunit	contributes to	Mre11 complex	`GO:0030870` GO:0030870 names Xrs2p as a constituent of the complex. `DOI:10.1093/nar/27.10.2072` Chamankhah and Xiao 1999 studied the yeast Mre11-Rad50-Xrs2 complex.
Mre11 complex	supports	DNA repair	`GO:0030870` GO:0030870 defines the complex as involved in DNA repair. `GO:0006281` GO:0006281 is the process term for DNA repair. `DOI:10.1128/MCB.19.11.7681` Bressan et al. 1999 connected the complex to homologous recombination-based DSB repair.
Mre11 complex	supports	reciprocal meiotic recombination	`GO:0030870` GO:0030870 defines the complex as involved in meiotic recombination. `GO:0007131` GO:0007131 is the process term for reciprocal meiotic recombination. `DOI:10.1007/s10577-007-1147-9` Borde 2007 reviewed roles of the Mre11 complex in meiotic recombination.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the Mre11, Rad50 and Xrs2 constituents of the Mre11 complex. GO:0030870 exactly identifies the trimeric Mre11 complex and names the Saccharomyces cerevisiae Mre11p, Rad50p and Xrs2p constituents, but exact cross-eukaryotic InterPro, Pfam, NCBIfam or UniProtKB family boundaries for the three budding-yeast subunit classes need narrower follow-up curation.

Evidence

GO:0030870 Gene Ontology cellular-component term for the Mre11 complex.
GO:0140513 Gene Ontology cellular-component parent term for nuclear protein-containing complexes.
GO:0006281 Gene Ontology biological-process term for DNA repair.
GO:0007131 Gene Ontology biological-process term for reciprocal meiotic recombination.
PMID:10219078 PubMed identifier for Chamankhah and Xiao 1999, the Nucleic Acids Research paper on formation of the yeast Mre11-Rad50-Xrs2 complex.
DOI:10.1093/nar/27.10.2072 DOI for Chamankhah and Xiao 1999, 'Formation of the yeast Mre11-Rad50-Xrs2 complex is correlated with DNA repair and telomere maintenance', verified through PubMed and PMC.
PMID:10523656 PubMed identifier for Bressan, Baxter and Petrini 1999, the Molecular and Cellular Biology paper on Mre11-Rad50-Xrs2 and homologous recombination-based double-strand-break repair.
DOI:10.1128/MCB.19.11.7681 DOI for Bressan, Baxter and Petrini 1999, verified through PubMed and PMC.
PMID:11988766 PubMed identifier for D'Amours and Jackson 2002, the Nature Reviews Molecular Cell Biology review cited by the GO:0030870 definition.
DOI:10.1038/nrm805 DOI for D'Amours and Jackson 2002, verified through PubMed.
PMID:17674145 PubMed identifier for Borde 2007, the Chromosome Research review cited by the GO:0030870 definition.
DOI:10.1007/s10577-007-1147-9 DOI for Borde 2007, verified through PubMed.

Curation history

2026-09-27T09:32:46Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-27T09:33:41Z codex · EXPANDED_RECORD — Added GO MRX/MRN synonymy, nuclear protein-containing-complex parentage, three reviewed-label-only Mre11-complex constituent rows, budding-yeast scope, DNA-repair and meiotic-recombination functions, GO/PubMed/DOI evidence, a nonmechanistic function graph, and an Mre11 subunit-grounding TODO.
2026-09-27T09:46:49Z codex · ADDRESS_REVIEW — #1651: narrowed the third Mre11-complex component row from Xrs2/Nbs1 with XRS2 and NBN gene symbols to a Saccharomyces cerevisiae Xrs2 row backed by the component-level evidence.

Source: data/structures/other/mre11_complex.yaml