DiaA complex

GO:1990125 · Other · Multiprotein complex · Proposed

A homotetrameric protein complex consisting of a symmetrical pair of DiaA homodimers. Facilitates DnaA binding to the origin of replication during replication initiation. [GO:1990125]

Synonyms: DiaA homotetramer

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
DiaA DnaA-binding protein	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	diaA	4 copies per DiaA homotetramer	UNKNOWN	Homodimerizing DiaA subunit whose tetrameric complex binds DnaA and facilitates DnaA loading at oriC. `GO:1990125` GO:1990125 defines the DiaA complex as a homotetrameric complex made of a symmetrical pair of DiaA homodimers. `PMID:17699754` Keyamura et al. 2007 determined the E. coli DiaA structure and showed that DiaA forms homotetramers.

Taxonomic distribution

NCBITaxon:562 Escherichia coli — COMMON: Keyamura et al. 2007 resolved the homotetrameric DiaA complex in E. coli. [PMID:17699754]

Canonical examples

NCBITaxon:562 Escherichia coli — Keyamura et al. 2007 solved the E. coli DiaA crystal structure and tested DiaA homotetramerization during replication initiation. [PMID:17699754]

Functions

DNA replication initiation GO:0006270 — The DiaA homotetramer facilitates DnaA binding to the origin of replication during DNA replication initiation.
- GO:1990125 GO:1990125 defines the DiaA complex by its facilitation of DnaA binding to the replication origin during initiation.
- GO:0006270 GO:0006270 is the Gene Ontology biological-process term for DNA replication initiation.
- PMID:17699754 Keyamura et al. 2007 showed that E. coli DiaA homotetramerization and DnaA-binding activity are required for DiaA stimulation of initiation.

Mechanism graphs

DiaA facilitates DnaA loading (FUNCTION)

DiaA subunits form a homotetrameric complex that facilitates DnaA loading at oriC during DNA replication initiation.

Subject	Predicate	Object	Evidence
DiaA DnaA-binding protein	contributes to	DiaA complex	`GO:1990125` GO:1990125 defines the DiaA complex as a homotetrameric protein complex. `PMID:17699754` Keyamura et al. 2007 showed that E. coli DiaA forms homotetramers.
DiaA complex	facilitates	DNA replication initiation	`GO:1990125` GO:1990125 defines the DiaA complex by its facilitation of DnaA binding to the origin of replication during initiation. `PMID:17699754` Keyamura et al. 2007 reported that DiaA homotetramerization is required for stimulation of initiation by DiaA.

Discussions

CURATION_TODO (OPEN): Resolve an exact source-neutral DiaA grounding for the DiaA complex. GO:1990125 defines a DiaA homotetramer, but an exact source-neutral InterPro, Pfam, NCBIfam or UniProt family CURIE for the DiaA protein constituent was not curated in this pass.
INTERPRETATION (RESOLVED): Leave DnaA and oriC DNA out of the scoped GO:1990125 DiaA complex. GO:1990125 denotes the free DiaA homotetramer. GO models the DiaA-containing DnaA-oriC protein-DNA assembly separately as GO:1990102, so DnaA and oriC are binding partners in that larger complex rather than constituents of GO:1990125.

Evidence

GO:1990125 Gene Ontology cellular-component term for the DiaA complex and its exact DiaA homotetramer synonym.
GO:0032991 OLS reports GO:0032991 protein-containing complex as the direct GO:1990125 is-a parent.
GO:1990102 OLS reports GO:1990102 DnaA-DiaA complex as the separate DiaA-bound DnaA-oriC protein-DNA complex that has GO:1990125 as a part.
GO:0006270 Gene Ontology biological-process term for DNA replication initiation.
PMID:17699754 PubMed identifier for Keyamura et al. 2007, the Genes & Development paper cited by GO:1990125.
DOI:10.1101/gad.1561207 DOI for Keyamura et al. 2007, 'The interaction of DiaA and DnaA regulates the replication cycle in E. coli by directly promoting ATP DnaA-specific initiation complexes', as reported by PubMed.

Curation history

2026-10-01T07:47:55Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-01T07:48:47Z codex · EXPANDED_RECORD — Added GO synonymy, protein-containing-complex parentage, a reviewed-label-only DiaA component, E. coli homotetramer evidence, DNA-replication-initiation function evidence, GO/PubMed/DOI evidence, a nonmechanistic initiation graph, and grounding/boundary discussions.

Source: data/structures/other/diaa_complex.yaml