Ndc80 complex

GO:0031262 · Other · Multiprotein complex · Proposed

A protein complex conserved among eukaryotes that forms part of the kinetochore and plays an essential role in forming stable kinetochore-microtubule attachments. The complex contains proteins known in several species, including budding and fission yeasts, as Ndc80p, Nuf2p, Spc24p, and Spc25p. In vertebrates it is part of the outer plate of the kinetochore. [GO:0031262]

Synonyms: Nuf2-Ndc80 complex

Part of: outer kinetochore (GO:0000940); kinetochore (GO:0000776)

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
Ndc80 subunit family	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NDC80	UNKNOWN	Named Ndc80-family constituent of the conserved Ndc80 complex. `GO:0031262` GO:0031262 names Ndc80 proteins as constituents of the conserved Ndc80 complex. `DOI:10.1093/emboj/20.4.777` Janke et al. 2001 analyzed budding-yeast Ndc80p within a complex that also contains Nuf2p, Spc24p and Spc25p.
Nuf2 subunit family	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NUF2	UNKNOWN	Named Ndc80-complex constituent that pairs with Ndc80-family subunits in the outer-kinetochore complex. `GO:0031262` GO:0031262 names Nuf2 proteins as constituents of the conserved Ndc80 complex. `DOI:10.1093/emboj/20.4.777` Janke et al. 2001 identified budding-yeast Nuf2p with Ndc80p, Spc24p and Spc25p at the kinetochore.
Spc24 subunit family	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	SPC24	UNKNOWN	Named Spc24-family constituent of the conserved Ndc80 complex. `GO:0031262` GO:0031262 names Spc24 proteins as constituents of the conserved Ndc80 complex. `DOI:10.1093/emboj/20.4.777` Janke et al. 2001 identified budding-yeast Spc24p as an Ndc80-complex member.
Spc25 subunit family	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	SPC25	UNKNOWN	Named Spc25-family constituent of the conserved Ndc80 complex. `GO:0031262` GO:0031262 names Spc25 proteins as constituents of the conserved Ndc80 complex. `DOI:10.1093/emboj/20.4.777` Janke et al. 2001 identified budding-yeast Spc25p as an Ndc80-complex member.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast has a four-subunit Ndc80 complex containing Ndc80p, Nuf2p, Spc24p and Spc25p at the kinetochore. [DOI:10.1093/emboj/20.4.777]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Reference yeast system in which the Ndc80-Nuf2-Spc24-Spc25 outer-kinetochore complex was genetically and cytologically characterized. [DOI:10.1093/emboj/20.4.777]

Functions

kinetochore-microtubule attachment — The Ndc80 complex forms an outer-kinetochore interface needed to generate stable attachments between kinetochores and spindle microtubules.
- GO:0031262 GO:0031262 defines the Ndc80 complex by its role in stable kinetochore-microtubule attachments.
- DOI:10.1534/genetics.112.145276 Biggins 2013 reviewed Ndc80 as a core outer kinetochore microtubule-coupling complex.

Mechanism graphs

Ndc80 forms the outer-kinetochore microtubule-coupling complex (ASSEMBLY)

The conserved Ndc80 complex is an outer-kinetochore subcomplex whose four protein subunits assemble into a module required for stable kinetochore-microtubule attachment.

Subject	Predicate	Object	Evidence
Ndc80 complex	is part of	outer kinetochore	`GO:0031262` GO:0031262 defines the Ndc80 complex as a kinetochore complex with an outer-plate localization in vertebrates. `DOI:10.1534/genetics.112.145276` Biggins 2013 reviewed Ndc80 as an outer kinetochore complex.
outer kinetochore	is part of	kinetochore	`GO:0000940` GO:0000940 defines the outer kinetochore as the region of a kinetochore most external to centromeric DNA.
Ndc80 complex	stabilizes	kinetochore-microtubule attachment	`GO:0031262` GO:0031262 defines the Ndc80 complex by its role in stable kinetochore-microtubule attachments. `DOI:10.1534/genetics.112.145276` Biggins 2013 reviewed Ndc80 complex function at the kinetochore-microtubule interface.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the Ndc80, Nuf2, Spc24 and Spc25 subunits. The GO complex term spans orthologous Ndc80-family complexes across eukaryotes, and no exact InterPro, Pfam, NCBIfam or UniProtKB family CURIE was verified for these subunit families in this pass.
INTERPRETATION (RESOLVED): Keep the broader KMN network and the yeast Dam1/DASH complex outside the Ndc80-complex component list. GO:0031262 defines Ndc80 as the Ndc80-Nuf2-Spc24-Spc25 complex itself; other outer-kinetochore microtubule-binding or bridge complexes belong as neighbors, not as Ndc80 constituents.

Evidence

GO:0031262 Gene Ontology cellular-component term for the Ndc80 complex.
GO:0000940 Gene Ontology cellular-component term for the outer kinetochore, the region that contains the Ndc80 complex.
GO:0000776 Gene Ontology cellular-component term for kinetochore.
DOI:10.1093/emboj/20.4.777 Janke et al. 2001, The budding yeast proteins Spc24p and Spc25p interact with Ndc80p and Nuf2p at the kinetochore and are important for kinetochore clustering and checkpoint control, The EMBO Journal.
DOI:10.1534/genetics.112.145276 Biggins 2013, The composition, functions, and regulation of the budding yeast kinetochore, Genetics.

Curation history

2026-09-15T18:53:43Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-15T18:54:48Z codex · EXPANDED_RECORD — Added GO hierarchy and parthood, four reviewed label-only Ndc80 subunit families, a Saccharomyces cerevisiae example, kinetochore-microtubule attachment function, DOI/GO evidence, a nonmechanistic outer-kinetochore attachment graph, and boundary TODOs.
2026-09-15T19:04:34Z codex · REFINED_DEFINITION — Replaced the initial Ndc80 definition paraphrase with the fuller GO:0031262 wording that names conserved Ndc80p, Nuf2p, Spc24p and Spc25p composition.
2026-09-15T19:15:02Z codex · REVIEW_FIXES — Resolved #1016 and #1017 by moving outer kinetochore from parent_structures to part_of, changing the outer-kinetochore graph edge to parthood, and narrowing unsupported subunit orientation phrasing in the Ndc80, Spc24 and Spc25 component roles.

Source: data/structures/other/ndc80_complex.yaml