DnaA-L2 complex

GO:1990082 · Other · Multiprotein complex · Proposed

A protein complex that inhibits unwinding of DNA at the origin of replication and assembly of the pre-primosome. In E. coli, this complex is composed of DnaA and of the ribosomal protein L2. [GO:1990082]

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
DnaA replication initiation protein	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	dnaA		UNKNOWN	Replication initiator constituent bound by ribosomal protein L2 in the DnaA-L2 complex. `GO:1990082` GO:1990082 defines the E. coli DnaA-L2 complex as being composed of DnaA and ribosomal protein L2. `PMID:21288885` Chodavarapu et al. 2011 reported that full-length and truncated E. coli L2 physically interact with the N-terminal region of DnaA.
50S ribosomal protein L2	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	rplB		UNKNOWN	DnaA-binding ribosomal protein constituent that inhibits DnaA oligomer formation, oriC unwinding, and downstream assembly of the prepriming complex. `GO:1990082` GO:1990082 defines the E. coli DnaA-L2 complex as being composed of ribosomal protein L2 and DnaA. `PMID:21288885` Chodavarapu et al. 2011 purified an oriC plasmid replication inhibitor as a truncated ribosomal protein L2 and showed that truncated or mature L2 interacts with DnaA.

Taxonomic distribution

NCBITaxon:562 Escherichia coli — COMMON: Chodavarapu et al. 2011 studied E. coli ribosomal protein L2 binding to DnaA and inhibition of DnaA-dependent oriC replication initiation reactions. [PMID:21288885]

Canonical examples

NCBITaxon:562 Escherichia coli — Chodavarapu et al. 2011 used E. coli DnaA and L2 to define L2-DnaA binding and L2 inhibition of origin unwinding and prepriming-complex assembly. [PMID:21288885]

Functions

negative regulation of DNA-templated DNA replication initiation GO:0032297 — The E. coli DnaA-L2 complex negatively regulates replication initiation by inhibiting DnaA-dependent oriC unwinding and assembly of the pre-primosome.
- GO:1990082 GO:1990082 defines the DnaA-L2 complex by inhibition of origin unwinding and pre-primosome assembly.
- GO:0032297 GO:0032297 is the Gene Ontology biological-process term for negative regulation of DNA-templated DNA replication initiation.
- PMID:21288885 Chodavarapu et al. 2011 showed that ribosomal protein L2 inhibits oriC initiation by interfering with DnaA oligomerization, oriC unwinding, and prepriming-complex assembly in vitro.

Mechanism graphs

L2 inhibits DnaA initiation activity (FUNCTION)

Ribosomal protein L2 binds DnaA to form a complex that supports negative regulation of replication initiation by interfering with DnaA-dependent origin unwinding and pre-primosome assembly.

Subject	Predicate	Object	Evidence
DnaA replication initiation protein	contributes to	DnaA-L2 complex	`GO:1990082` GO:1990082 defines the E. coli complex as being composed of DnaA and ribosomal protein L2.
50S ribosomal protein L2	contributes to	DnaA-L2 complex	`GO:1990082` GO:1990082 names ribosomal protein L2 as a constituent of the DnaA-L2 complex. `PMID:21288885` Chodavarapu et al. 2011 reported physical interaction between E. coli L2 and the N-terminal region of DnaA.
DnaA-L2 complex	supports	negative regulation of DNA-templated DNA replication initiation	`GO:1990082` GO:1990082 defines the complex by inhibition of origin unwinding and pre-primosome assembly. `PMID:21288885` Chodavarapu et al. 2011 found that L2 inhibits DnaA-dependent oriC unwinding and subsequent prepriming-complex assembly.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral DnaA and ribosomal protein L2 family groundings for the DnaA-L2 complex. GO:1990082 names DnaA and ribosomal protein L2 as the E. coli constituents of the DnaA-L2 complex. Exact source-neutral InterPro, Pfam, NCBIfam or UniProt family CURIEs need narrower curation before these components can be grounded.
INTERPRETATION (RESOLVED): Keep the DnaA-L2 complex distinct from DnaA-Dps and RIDA complexes. GO:1990082 denotes DnaA bound to ribosomal protein L2, whereas GO:1990084 denotes the DnaA-Dps complex, GO:1990083 denotes the DnaA-Hda complex, and GO:1990085 denotes Hda bound to the DnaN beta clamp.

Evidence

GO:1990082 Gene Ontology cellular-component term for the DnaA-L2 complex.
GO:1990078 QuickGO reports GO:1990082 DnaA-L2 complex as an is-a child of GO:1990078 replication inhibiting complex.
GO:1990083 Gene Ontology cellular-component term for the separately scoped DnaA-Hda complex.
GO:1990084 Gene Ontology cellular-component term for the separately scoped DnaA-Dps complex.
GO:1990085 Gene Ontology cellular-component term for the separately scoped Hda-beta clamp complex.
GO:0032297 Gene Ontology biological-process term for negative regulation of DNA-templated DNA replication initiation.
PMID:21288885 PubMed identifier for Chodavarapu, Felczak and Kaguni 2011, the Nucleic Acids Research paper cited by GO:1990082.
DOI:10.1093/nar/gkq1203 DOI for Chodavarapu et al. 2011, 'Two forms of ribosomal protein L2 of Escherichia coli that inhibit DnaA in DNA replication', as reported by PubMed.

Curation history

2026-10-01T14:15:11Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-01T14:17:04Z codex · EXPANDED_RECORD — Added replication-inhibiting-complex parentage, reviewed-label-only DnaA and ribosomal-protein-L2 components, E. coli DnaA-L2 evidence, negative-DNA-replication-initiation function evidence, GO/PubMed/DOI evidence, a nonmechanistic DnaA-L2 regulatory graph, and grounding/boundary discussions.

Source: data/structures/other/dnaa_l2_complex.yaml