bglX encodes a signal-peptide-bearing glycoside hydrolase family 3 protein predicted to act as a periplasmic beta-glucosidase. Its supported role is hydrolysis of terminal non-reducing beta-D-glucosyl residues during carbohydrate utilization; its physiological substrate remains unknown.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004553 hydrolase activity, hydrolyzing O-glycosyl compounds | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: This broad glycoside-hydrolase activity is consistent with the GH3 assignment. Reason: Beta-glucosidase activity is the more informative core molecular function. Supporting Evidence: file:PSEPK/bglX/bglX-uniprot.txt Belongs to the glycosyl hydrolase 3 family. |
| GO:0005975 carbohydrate metabolic process | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Carbohydrate metabolism is correct but too broad to define the core role. Reason: The predicted beta-glucosidase reaction provides the more useful functional description. |
| GO:0008422 beta-glucosidase activity | IEA GO_REF:0000120 | ACCEPT | Summary: GH3 family membership and the predicted reaction support beta-glucosidase activity. Reason: UniProt predicts hydrolysis of terminal non-reducing beta-D-glucosyl residues and identifies a multidomain GH3-family protein. Supporting Evidence: file:PSEPK/bglX/bglX-uniprot.txt Reaction=Hydrolysis of terminal, non-reducing beta-D-glucosyl residues file:PSEPK/bglX/bglX-uniprot.txt Belongs to the glycosyl hydrolase 3 family. |
| GO:0009251 glucan catabolic process | IEA GO_REF:0000118 | KEEP AS NON CORE | Summary: The predicted exo-beta-glucosidase reaction is compatible with glucan catabolism. Reason: The GH3 architecture and terminal beta-D-glucosyl-residue hydrolysis support breakdown of beta-glucosyl oligosaccharides or glucans, although the physiological substrate has not been identified. Supporting Evidence: file:PSEPK/bglX/bglX-uniprot.txt Reaction=Hydrolysis of terminal, non-reducing beta-D-glucosyl residues |
| GO:0042597 periplasmic space | IEA GO_REF:0000044 | ACCEPT | Summary: The signal peptide and UniProt localization support the periplasm. Reason: UniProt predicts an N-terminal signal peptide and periplasmic localization. Supporting Evidence: file:PSEPK/bglX/bglX-uniprot.txt SUBCELLULAR LOCATION: Periplasm file:PSEPK/bglX/bglX-uniprot.txt FT SIGNAL 1..20 |
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Download this section (compressed HTML)Q: Which beta-glucosides are transported to and hydrolyzed by periplasmic BglX in KT2440?
Experiment: Purify BglX and measure hydrolysis across beta-glucoside and beta-glucan substrates, then test substrate utilization in a bglX deletion strain.
Type: biochemical substrate panel and genetics
What is not known — curated, literature-grounded statements of the open unknowns (the inverse of core functions).
Gap: The physiological beta-glucoside or glucan substrate of bglX is unknown.
OPEN BIOLOGY
What is known: GH3 family membership supports beta-glucosidase chemistry, but does not link bglX to a particular environmental carbohydrate or to flavonoid catabolism.
Significance: Substrate identification is needed to place bglX in a specific catabolic route.
What would resolve it: Purify BglX and test a panel of beta-glucosides and beta-glucans.
Provenance (the field's own admissions):
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