bindosome complex
A membrane-associated protein complex found in archaea that consists of sugar binding proteins assembled via a type IV pilin-like assembly system. The complex is located at the cell surface and functions in sugar uptake by facilitating the interaction between solute binding proteins and ABC transporters. The complex forms high molecular mass structures (400-600 kDa) that are integrated within or closely associated with the S-layer. [GO:7770042]
Components
| Component | Type | Part of / acts on | Grounding | Genes | Stoichiometry | Essential | Role |
|---|---|---|---|---|---|---|---|
| bindosome sugar-binding proteins | Protein | part of | Reviewed label only (reviewed name; no accession asserted) | UNKNOWN | Cell-surface solute-binding proteins assembled into high-molecular-mass complexes that position captured sugars near membrane ABC importers.
|
Taxonomic distribution
NCBITaxon:2287Saccharolobus solfataricus — COMMON: The bindosome was characterized as cell-surface 400 and 600 kDa sugar-binding-protein complexes in the archaeon then named Sulfolobus solfataricus. [DOI:10.1007/s00792-010-0353-0]
Canonical examples
NCBITaxon:2287Saccharolobus solfataricus — Original crenarchaeal model in which ConA-enriched cell-envelope fractions resolved bindosome complexes by Blue-native PAGE and size-exclusion chromatography. [DOI:10.1007/s00792-010-0353-0]
Functions
- cell-surface sugar-binding protein organization — The bindosome organizes archaeal sugar-binding proteins at the cell surface for sugar uptake through cognate membrane ABC transporters.
GO:7770042GO:7770042 describes the bindosome as facilitating the interaction between solute-binding proteins and ABC transporters during sugar uptake.DOI:10.1007/s00792-010-0353-0Zolghadr et al. 2011 connected Bas-dependent surface localization of sugar-binding-protein complexes with glucose uptake in S. solfataricus.
Discussions
- INTERPRETATION (RESOLVED): Should BasEF or BasABC be curated as constituents of the mature bindosome complex? GO:7770042 identifies the bindosome as the assembled sugar-binding-protein complex. Zolghadr et al. showed that BasEF and BasABC are type-IV-pilin-like machinery required for functional surface localization of the sugar-binding proteins; BasEF was not required for formation of the extracted 400 and 600 kDa complexes themselves. The Bas system was therefore left out of the mature bindosome component list.
- CURATION_TODO (OPEN): Resolve whether SlaA or other S-layer material should be modeled as a bindosome constituent or as a neighboring envelope scaffold. The 600 kDa S. solfataricus sugar-binding-protein complex co-purified with the main S-layer protein SlaA, whereas the 400 kDa complex contained GlcS and SSO3043 and the GO definition keeps the bindosome scoped to sugar-binding proteins. This pass therefore records the S-layer association without making SlaA a source-neutral bindosome subunit.
Evidence
GO:7770042Gene Ontology cellular-component term for the bindosome complex.GO:0098796Gene Ontology cellular-component parent term for membrane protein complexes.DOI:10.1007/s00792-010-0353-0Zolghadr et al. 2011, The bindosome is a structural component of the Sulfolobus solfataricus cell envelope, Extremophiles.
Curation history
2026-10-03T05:56:11Zcodex · CREATED_RECORD — Scaffolded by scripts/new_record.py2026-10-03T05:57:38Zcodex · EXPANDED_RECORD — Added membrane-protein-complex parentage, a reviewed-label-only sugar-binding-protein constituent, Saccharolobus solfataricus taxonomy, a cell-surface sugar-binding organization function, GO and DOI evidence, and Bas-machinery and S-layer boundary discussions.2026-10-03T06:16:32Zcodex · ADDRESS_REVIEW — Qualified the bindosome constituent grounding note so SSO3043 and SSO1273 are described as detected putative solute-binding proteins rather than proven sugar-binding proteins; addresses PR #1969 review issue #1970.