DnaA-DiaA complex

GO:1990102 · Other · Nucleoprotein complex · Proposed

A protein-DNA complex containing a tetramer of DiaA attached to multiple DnaA molecule bound to oriC DNA. Regulates timely initiation of chromosomal replication during the cell cycle by stimulating assembly of DnaA-oriC complexes, conformational changes in ATP-DnaA initiation complexes, and unwinding of oriC duplex DNA. [GO:1990102]

Synonyms: DnaA-DiaA-DNA complex

Has part: DnaA-oriC complex (GO:1990101); DiaA complex (GO:1990125)

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	Homotetramer-forming DiaA constituent that binds multiple DnaA molecules at oriC. `GO:1990102` GO:1990102 defines the DnaA-DiaA complex as containing a tetramer of DiaA attached to DnaA on oriC DNA. `GO:1990125` GO:1990125 defines the DiaA complex as a homotetrameric protein complex. `PMID:17699754` Keyamura et al. 2007 determined the E. coli DiaA structure and found that DiaA forms homotetramers that bind multiple DnaA molecules.
DnaA replication initiation protein	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	dnaA		UNKNOWN	DnaA initiator constituent bound to oriC DNA and contacted by DiaA. `GO:1990102` GO:1990102 defines the DnaA-DiaA complex as DiaA attached to multiple DnaA molecules bound to oriC DNA. `PMID:15326179` Ishida et al. 2004 identified DiaA as an E. coli DnaA-associating factor that binds directly to DnaA. `PMID:17699754` Keyamura et al. 2007 analyzed DiaA-dependent assembly of multiple DnaA molecules on E. coli oriC.
oriC origin DNA	Dna	part of	Reviewed label only (reviewed name; no accession asserted)			UNKNOWN	Origin DNA scaffold carrying the DnaA-bound sites contacted by DiaA. `GO:1990102` GO:1990102 scopes the DnaA-DiaA complex to DiaA attached to multiple DnaA molecules bound to oriC DNA. `PMID:17699754` Keyamura et al. 2007 tested DiaA stimulation of DnaA assembly on E. coli oriC DNA.

Taxonomic distribution

NCBITaxon:562 Escherichia coli — COMMON: Keyamura et al. 2007 studied DiaA-dependent DnaA initiation-complex assembly in E. coli. [PMID:17699754]

Canonical examples

NCBITaxon:562 Escherichia coli — Keyamura et al. 2007 resolved E. coli DiaA as a homotetramer and tested its stimulation of DnaA-oriC initiation-complex assembly. [PMID:17699754]

Functions

DNA replication initiation GO:0006270 — The DnaA-DiaA complex promotes timely chromosomal replication initiation by stimulating assembly of DnaA on oriC.
- GO:1990102 GO:1990102 defines this DiaA-containing complex by its stimulation of DnaA-oriC initiation-complex assembly.
- GO:0006270 GO:0006270 is the Gene Ontology biological-process term for DNA replication initiation.
- PMID:15326179 Ishida et al. 2004 identified DiaA as a DnaA-associating factor needed for timely E. coli chromosomal replication initiation.
- PMID:17699754 Keyamura et al. 2007 showed that E. coli DiaA stimulates the assembly of multiple DnaA molecules on oriC.

Mechanism graphs

DiaA promotes DnaA-oriC assembly (FUNCTION)

A DiaA homotetramer contacts DnaA bound to oriC DNA to form a DnaA-DiaA-DNA complex that promotes DNA replication initiation.

Subject	Predicate	Object	Evidence
DiaA DnaA-binding protein	contributes to	DnaA-DiaA complex	`GO:1990102` GO:1990102 defines the complex as containing a tetramer of DiaA.
DnaA replication initiation protein	contributes to	DnaA-DiaA complex	`GO:1990102` GO:1990102 defines the complex around DiaA attached to DnaA bound to oriC DNA.
oriC origin DNA	scaffolds	DnaA-DiaA complex	`GO:1990102` GO:1990102 scopes the complex to DiaA attached to DnaA molecules bound to oriC DNA. `PMID:17699754` Keyamura et al. 2007 tested DiaA-dependent assembly of DnaA on oriC.
DnaA-DiaA complex	promotes	DNA replication initiation	`GO:1990102` GO:1990102 defines this complex as regulating timely chromosomal replication initiation. `PMID:17699754` Keyamura et al. 2007 found that DiaA tetramers stimulate assembly of ATP-DnaA-oriC initiation complexes.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral DiaA, DnaA and oriC origin DNA groundings for the DnaA-DiaA complex. GO:1990102 defines the DnaA-DiaA complex around a DiaA tetramer attached to DnaA molecules bound to oriC DNA. Exact source-neutral InterPro, Pfam, NCBIfam, UniProt family or SO sequence-feature CURIEs for these primitive components need narrower curation before the labels can be grounded.
INTERPRETATION (RESOLVED): Keep the GO:1990102 DnaA-DiaA complex distinct from the free DnaA-oriC and DiaA complexes and from DnaB-DnaC helicase loading. GO:1990102 is the DiaA-containing DnaA-oriC state. GO models the DnaA-oriC complex as GO:1990101, the DiaA homotetramer as GO:1990125, and the DnaB-DnaC helicase-loading state separately as GO:1990100.

Evidence

GO:1990102 Gene Ontology cellular-component term for the DnaA-DiaA complex and its exact DnaA-DiaA-DNA complex synonym.
GO:1990077 OLS reports GO:1990077 primosome complex as the direct GO:1990102 is-a parent.
GO:1990101 OLS reports GO:1990101 DnaA-oriC complex as a GO:1990102 has-part structure.
GO:1990125 OLS reports GO:1990125 DiaA complex as a GO:1990102 has-part structure.
GO:0006270 Gene Ontology biological-process term for DNA replication initiation.
PMID:15326179 PubMed identifier for Ishida et al. 2004, the Journal of Biological Chemistry paper cited by GO:1990102.
DOI:10.1074/jbc.M402762200 DOI for Ishida et al. 2004, 'DiaA, a novel DnaA-binding protein, ensures the timely initiation of Escherichia coli chromosome replication', as reported by PubMed.
PMID:17699754 PubMed identifier for Keyamura et al. 2007, the Genes & Development paper cited by GO:1990102 and 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

2026-10-01T07:17:23Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-01T07:18:33Z codex · EXPANDED_RECORD — Added GO synonymy, primosome-complex parentage, DnaA-oriC and DiaA-complex part links, reviewed-label-only DiaA, DnaA and oriC DNA components, E. coli DiaA initiation evidence, DNA-replication-initiation function evidence, GO/PubMed/DOI evidence, a nonmechanistic initiation graph, and grounding/boundary discussions.
2026-10-01T07:19:13Z codex · FIX_EVIDENCE_NOTES — Narrowed the E. coli taxonomic-distribution note to the cited Keyamura et al. 2007 source and normalized the Genes & Development journal title.

Source: data/structures/other/dnaa_diaa_complex.yaml