algE encodes an outer-membrane AlgE-family alginate export protein in Pseudomonas putida KT2440. It likely forms the alginate permeability pore at the outer-membrane step of alginate polymer export.
Definition: Enables passage of alginate polymer through a membrane channel or pore.
Justification: AlgE is described by similarity as having channel-forming properties and probably functioning as an alginate permeability pore, but the GOA rows capture only outer-membrane localization and alginate biosynthesis process, not the pore activity itself.
Parent term: channel activity
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0009279 cell outer membrane | IEA GO_REF:0000044 | ACCEPT | Summary: algE is correctly localized to the cell outer membrane. Reason: AlgE functions as an outer-membrane alginate pore, so the outer-membrane location is intrinsic to the core channel role. Falcon supports this from AlgE homolog structures and a modeled P. putida AlgE-containing AlgEKX complex, but direct Q88NC8/PP_1284 KT2440 biochemical evidence was not recovered. Supporting Evidence: file:PSEPK/algE/algE-uniprot.txt SUBCELLULAR LOCATION: Cell outer membrane file:PSEPK/algE/algE-goa.tsv GO:0009279 cell outer membrane file:PSEPK/algE/algE-deep-research-falcon.md Characterized Pseudomonas AlgE homologs are outer-membrane 18-stranded beta-barrel alginate export porins, and a 2022 AlgEKX model includes P. putida AlgE. |
| GO:0042121 alginic acid biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: AlgE is part of alginate biosynthesis/export and should retain the alginic acid biosynthetic process annotation. Reason: UniProt places AlgE in alginate biosynthesis and describes it as probably functioning as an alginate permeability pore, consistent with a core pathway role in producing/exporting alginate polymer. Falcon supports AlgE as the outer-membrane translocation route in the envelope-spanning alginate secretion apparatus, but the evidence is homolog/ortholog based for Q88NC8. Supporting Evidence: file:PSEPK/algE/algE-uniprot.txt Has non-porin-like, channel-forming properties and probably functions as an alginate permeability pore file:PSEPK/algE/algE-uniprot.txt PATHWAY: Glycan biosynthesis; alginate biosynthesis file:PSEPK/algE/algE-goa.tsv GO:0042121 alginic acid biosynthetic process file:PSEPK/algE/algE-deep-research-falcon.md AlgE-family studies place AlgE downstream of Alg8/Alg44 polymerization and AlgK/AlgX-associated periplasmic export/modification, providing the outer-membrane channel for alginate secretion. |
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Download this section (compressed HTML)Q: Does KT2440 AlgE form an alginate-specific outer-membrane pore with substrate selectivity comparable to characterized AlgE homologs?
Experiment: Reconstitute AlgE in proteoliposomes or planar bilayers and test alginate-dependent channel conductance and polymer passage.
Type: membrane channel assay
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