endospore cortex
The thick, loosely cross-linked peptidoglycan layer between the spore core and the coat of a mature bacterial endospore. [GO:0043595]
Synonyms: spore cortex
Part of: endospore external encapsulating structure (GO:0043591)
Xrefs: uniprot.location:SL-0364 — Spore cortex
Components
| Component | Type | Part of / acts on | Grounding | Genes | Stoichiometry | Essential | Role |
|---|---|---|---|---|---|---|---|
| endospore cortex peptidoglycan | Peptidoglycan | part of | Reviewed label only (reviewed name; no accession asserted) | ESSENTIAL | Thick, modified peptidoglycan layer that holds the mature endospore core in a dehydrated, heat-resistant state and is cleaved during germination.
|
Taxonomic distribution
NCBITaxon:1239Bacillota — COMMON: Endospore cortex is produced by endospore-forming Bacillota lineages and is lost from many non-sporulating members of the phylum. [DOI:10.1038/nrmicro2921]
Canonical examples
NCBITaxon:1423Bacillus subtilis — Classical model for endospore differentiation and the cortex layer that surrounds the dormant spore core. [DOI:10.1038/nrmicro2921]
Functions
- spore core dehydration — The endospore cortex helps maintain low water content in the spore core, a major physical basis for wet-heat resistance.
DOI:10.1128/9781555819323.ch10Setlow 2016 reviews the cortex contribution to low core water content and endospore wet-heat resistance.
Mechanism graphs
Endospore cortex maintains a dehydrated spore core (FUNCTION)
Modified cortex peptidoglycan surrounds the endospore core and contributes to the low core water content that makes dormant spores wet-heat resistant.
| Subject | Predicate | Object | Evidence |
|---|---|---|---|
| endospore cortex | maintains | dehydrated spore core |
|
| dehydrated spore core | enables | wet-heat resistance |
|
Discussions
- INTERPRETATION (RESOLVED): Keep the endospore cortex separate from the broader endospore external encapsulating structure. GO:0043595 denotes only the thick cortex layer, while GO:0043591 denotes the multilayered external structure containing the cortex, coat and outer membrane.
- CURATION_TODO (OPEN): Find an exact source-neutral grounding for endospore cortex peptidoglycan. The cortex is a peptidoglycan layer with characteristic chemical modifications, but its peptidoglycan constituent has no exact CHEBI, GO or other source-neutral family term in the curated identifier set.
Evidence
GO:0043595Gene Ontology cellular-component term for the endospore cortex.GO:0043591Gene Ontology cellular-component term for the endospore external encapsulating structure that contains the cortex.uniprot.location:SL-0364— Spore cortex UniProt Subcellular Location SL-0364 maps Spore cortex to GO:0043595 and places it under the Spore location.DOI:10.1128/9781555819323.ch10Setlow 2016, Spore Resistance Properties, in The Bacterial Spore.DOI:10.1038/nrmicro2921McKenney, Driks and Eichenberger 2012, The Bacillus subtilis endospore: assembly and functions of the multilayered coat, Nature Reviews Microbiology.
Curation history
2026-09-13T00:33:44Zcodex · CREATED_RECORD — Scaffolded by scripts/new_record.py2026-09-13T00:34:21Zcodex · EXPANDED_RECORD — Added the UniProt SL xref and synonym, endospore external structure parthood, cortex peptidoglycan component, Bacillota distribution, a Bacillus subtilis example, GO and literature evidence, a nonmechanistic dehydration graph, and cortex boundary discussions.2026-09-13T00:47:24Zcodex · ADDRESS_REVIEW — Resolved #726 by removing the component_ref from the whole endospore cortex graph node.