CMG complex
A protein complex that contains the GINS complex, Cdc45p, and the heterohexameric MCM complex, and that is involved in unwinding DNA during replication. [GO:0071162]
Synonyms: unwindosome
Components
| Component | Type | Part of / acts on | Grounding | Genes | Stoichiometry | Essential | Role |
|---|---|---|---|---|---|---|---|
| GINS complex | Protein complex | part of | GO:0000811 | 1 | UNKNOWN | Heterotetrameric GINS constituent subcomplex of the CMG helicase.
| |
| MCM complex | Protein complex | part of | GO:0042555 | 1 | UNKNOWN | Heterohexameric MCM constituent subcomplex of the CMG helicase.
| |
| Cdc45 protein | Protein | part of | Reviewed label only (reviewed name; no accession asserted) | CDC45 | 1 | UNKNOWN | Cdc45 constituent protein of the CMG helicase.
|
Taxonomic distribution
NCBITaxon:2759Eukaryota — COMMON: Akman and MacNeill describe Cdc45, MCM and GINS as CMG components that are essential for chromosomal DNA replication in eukaryotic cells. [PMID:19228417]
Canonical examples
NCBITaxon:284812Schizosaccharomyces pombe — Reference fission-yeast system in which Akman and MacNeill visualised GINS-MCM interactions in living cells from native chromosomal loci. [PMID:19228417]
Functions
- DNA replication
GO:0006260— The CMG complex supports DNA unwinding during eukaryotic DNA replication.GO:0071162GO:0071162 defines the CMG complex as involved in unwinding DNA during replication.GO:0006260GO:0006260 is the Gene Ontology biological-process term for DNA replication.PMID:19228417Akman and MacNeill 2009 describe the Cdc45, MCM and GINS components of CMG as essential for chromosomal DNA replication in eukaryotic cells.
Mechanism graphs
CMG supports replicative DNA unwinding (FUNCTION)
The GINS complex, heterohexameric MCM complex and Cdc45 form the eukaryotic CMG complex that supports DNA unwinding during replication.
| Subject | Predicate | Object | Evidence |
|---|---|---|---|
| GINS complex | contributes to | CMG complex |
|
| MCM complex | contributes to | CMG complex |
|
| Cdc45 protein | contributes to | CMG complex |
|
| CMG complex | supports | DNA replication |
|
Discussions
- CURATION_TODO (OPEN): Resolve an exact source-neutral family grounding for Cdc45 in the CMG complex. GO:0071162 exactly identifies the CMG complex and its Cdc45, GINS and MCM constituents, but an exact InterPro, Pfam, NCBIfam or UniProtKB family CURIE for the source-neutral Cdc45 component was not curated in this pass.
- INTERPRETATION (RESOLVED): Model GINS and MCM as constituent subcomplexes rather than flattening them into their protein subunits. GO:0071162 defines CMG as containing the GINS complex and the heterohexameric MCM complex, both of which have their own GO cellular-component identities and CellStructureMech records.
Evidence
GO:0071162Gene Ontology cellular-component term for the CMG complex.GO:0031261Gene Ontology cellular-component parent term for DNA replication preinitiation complexes.GO:0000811Gene Ontology cellular-component term for the GINS complex.GO:0042555Gene Ontology cellular-component term for the MCM complex.GO:0006260Gene Ontology biological-process term for DNA replication.PMID:19228417PubMed identifier listed by GO:0071162 as its definition cross-reference.DOI:10.1186/1471-2121-10-12DOI for Akman and MacNeill 2009, verified through PubMed.
Curation history
2026-09-27T17:11:23Zcodex · CREATED_RECORD — Scaffolded by scripts/new_record.py2026-09-27T17:12:21Zcodex · EXPANDED_RECORD — Added GO CMG synonymy, DNA replication preinitiation-complex parentage, GINS, MCM and Cdc45 constituent rows, Eukaryota scope, a Schizosaccharomyces pombe canonical example, DNA-replication function evidence, GO/PubMed/DOI provenance, a nonmechanistic CMG function graph, a Cdc45-grounding TODO and a resolved GINS/MCM subcomplex boundary note.2026-09-27T17:12:58Zcodex · TIGHTEN_EVIDENCE_SCOPE — Narrowed the Eukaryota taxonomic-distribution note so its row-level PubMed reference supports the whole assertion.