nucleoid

GO:0009295 · NUCLEOID · SUBCELLULAR_REGION · PROPOSED

The non-membrane-bounded subcellular region in which a bacterial chromosome is compacted and organized with nucleoid-associated proteins while remaining dynamically coupled to transcription and replication. [DOI:10.1038/nrmicro2261]

Components

Component	Type	Grounding	Genes	Stoichiometry	Essential	Role
chromosomal DNA	DNA				ESSENTIAL	The genome polymer whose compaction and spatial organization define the nucleoid. `DOI:10.1038/nrmicro2261` Dorman reviews chromosome organization in the bacterial nucleoid.
nucleoid-associated proteins	PROTEIN				CONDITIONAL	Bend, bridge, wrap, and constrain DNA and couple chromosome structure to gene expression. `DOI:10.1038/nrmicro2261` The review covers major NAP families and their regulatory roles.

Taxonomic distribution

NCBITaxon:2 Bacteria — UNIVERSAL: The chromosome occupies a nucleoid rather than a membrane-bounded nucleus. [DOI:10.1038/nrmicro2261]

Canonical examples

NCBITaxon:562 Escherichia coli — Best-characterized bacterial nucleoid and NAP system. [DOI:10.1038/nrmicro2261]

Functions

chromosome organization GO:0051276 — Compacts and spatially organizes the chromosome while preserving access to DNA.
- DOI:10.1038/nrmicro2261 Nucleoid architecture is integrated with gene expression.

Evidence

DOI:10.1038/nrmicro2261 Bacterial nucleoid-associated proteins, nucleoid structure and gene expression.

Curation history

2026-08-30T19:30:00Z codex · CREATED_RECORD — Added as a literature-backed foundational seed. Identity checked against the 2026-07-01 Gene Ontology release; requires human review.

Source: data/structures/nucleoid/nucleoid.yaml