Bacterial fused-relay fructose PTS uptake and catabolism

A reusable bacterial fused-relay module coupling phosphoenolpyruvate-driven phosphorelay, fructose translocation with phosphorylation to fructose 1-phosphate, and ATP-dependent production of fructose 1,6-bisphosphate. This implementation requires a fused EI-HPr-EIIA FruB protein and an EIIB'BC FruA transporter with two EIIB-type domains plus EIIC. Nitrogen-related PTS signaling and metabolism downstream of fructose 1,6-bisphosphate are outside the module boundary.

MODULE:bacterial_fructose_pts_catabolismDRAFTCONCRETEMetabolic Pathwaymodules/bacterial_fructose_pts_catabolism.yaml
PMID:18296519
Evidence of in vivo cross talk between the nitrogen-related and fructose-related branches of the carbohydrate phosphotransferase system of Pseudomonas putida.
KT2440 genetics and phosphotransfer analysis establish FruB and FruA as a complete fructose-intake PTS and define their fused relay architecture.
PMID:27933319
A Metabolic Widget Adjusts the Phosphoenolpyruvate-Dependent Fructose Influx in Pseudomonas putida.
The KT2440 fruBKA locus supplies cytosolic FruB, membrane FruA, and FruK for fructose uptake and fructose 1-phosphate metabolism.
UniProtKB:Q88PQ5
Pseudomonas putida KT2440 FruB
Q88PQ5 is the exact PSEPK EI-HPr-EIIA phosphorelay exemplar.
UniProtKB:Q88PQ3
Pseudomonas putida KT2440 FruA
Q88PQ3 is the exact PSEPK fructose-specific EIIB'BC exemplar.
UniProtKB:Q88PQ4
Pseudomonas putida KT2440 FruK
Q88PQ4 is the exact PSEPK 1-phosphofructokinase exemplar.
file:PSEPK/fruB/fruB-ai-review.yaml
Curated PSEPK FruB gene review
The review proposes a missing EIIA-to-EIIB phosphotransferase activity term for the FruB-to-FruA handoff.

FruB architecture varies across bacteria. This module is explicitly the fused EI-HPr-EIIA implementation represented by P. putida KT2440 and Xanthomonas campestris; split-relay fructose PTS systems require a separate architectural variant. The completed OpenScientist report records the initial three-part outline; final curation produced four parts by separating PEP entry from the internal FruB relay.

5Nodes
4Parts
0Variant Sets
0Variants
4Annotons
3Connections

Derived QC

Recommended-field compliance

60.0% recommended fields populated
  • module.knowledge_gaps[0] · status (0/1)
  • module.knowledge_gaps[0] · provenance (0/1)

Module deep research

✓ present

  • bacterial_fructose_pts_catabolism-deep-research-openscientist.md (openscientist)

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Gene-review completeness (3/6 grounded genes reviewed)

3 complete review(s) · 1 with deep research · 3 missing review · 2 reviewed but lacking deep research

Gene Review Complete Deep research
fruA Q88PQ3 ✓ ✓ ✗
fruB Q88PQ5 ✓ ✓ ✗
fruK Q88PQ4 ✓ ✓ ✓
FruK (Escherichia coli K-12) P0AEW9 ✗ — —
FruA (Escherichia coli K-12) P20966 ✗ — —
FruB (Xanthomonas campestris pv. campestris) P45597 ✗ — —

Details

Context
bacteriaNCBITaxon:2
Bacterial fused-relay fructose PTS uptake and catabolismMetabolic Pathwaybacterial_fructose_pts_catabolism
Context
bacteriaNCBITaxon:2

Connections

Phosphorylated FruB EI initiates transfer through its fused HPr and EIIA domains.
Phosphorylated FruB donates phosphate to the FruA EIIB domain.
FruA-produced beta-D-fructose 1-phosphate is the FruK substrate.
Part 1: phosphoenolpyruvate-dependent phosphorylation of fused FruB
FruB phosphoenolpyruvate entry reactionReactionfrub_pep_entry_reaction

Annotons

FruB phosphoenolpyruvate-protein phosphotransferase activity
frub_pep_phosphotransferase_activity
Participant: Family: fused fructose PTS EI-HPr-EIIA family
Family:
fused fructose PTS EI-HPr-EIIA familyPANTHER:PTHR46244:SF6
Representative Members: FruB (Pseudomonas putida KT2440)UniProtKB:Q88PQ5 FruB (Xanthomonas campestris pv. campestris)UniProtKB:P45597

Function

phosphoenolpyruvate-protein phosphotransferase activityGO:0008965
Substrates: phosphoenolpyruvate unphosphorylated FruB EI histidine
Products: pyruvate phosphorylated FruB EI histidine

GO:0008965 covers phosphate entry from phosphoenolpyruvate to the FruB EI histidine (RHEA:23880), not the complete internal relay.

Part 2: internal FruB EI-to-HPr-to-EIIA phosphorelay
Internal fused FruB phosphorelayReactionfrub_internal_phosphorelay

Annotons

FruB internal multiphosphoryl transfer
frub_internal_relay_activity
Participant: Family: fused fructose PTS EI-HPr-EIIA family
Family:
fused fructose PTS EI-HPr-EIIA familyPANTHER:PTHR46244:SF6
Representative Members: FruB (Pseudomonas putida KT2440)UniProtKB:Q88PQ5 FruB (Xanthomonas campestris pv. campestris)UniProtKB:P45597

Function

intramolecular EI-to-HPr-to-EIIA phosphorelay
Substrates: phosphorylated FruB EI histidine unphosphorylated FruB HPr and EIIA domains
Products: unphosphorylated FruB EI and HPr domains phosphorylated FruB EIIA histidine

The fused HPr and EIIA domains relay phosphate from the phosphorylated EI domain to the FruA EIIB phosphoacceptor. No existing GO molecular-function term captures this full internal relay; the curated FruB gene review proposes the narrower EIIA-to-EIIB phosphotransferase activity needed at the FruB-to-FruA handoff.

Part 3: fructose uptake coupled to fructose 1-phosphate formation
Fructose PTS transport and phosphorylationReactionfructose_pts_transport_phosphorylation

Annotons

FruA fructose-specific EIIB'BC activity
frua_transport_phosphorylation_activity
Participant: Family: fructose-specific PTS EIIB-EIIC family
Family:
fructose-specific PTS EIIB-EIIC familyPANTHER:PTHR30505
Representative Members: FruA (Pseudomonas putida KT2440)UniProtKB:Q88PQ3 FruA (Escherichia coli K-12)UniProtKB:P20966
Required Function:
protein-N(PI)-phosphohistidine-fructose phosphotransferase system transporter activityGO:0022877

Function

fructose phosphotransferase system transporter activityGO:0022877
Substrates: extracellular fructose phosphorylated FruB EIIA histidine
Products: intracellular beta-D-fructose 1-phosphate unphosphorylated FruB relay

FruA receives phosphate through its EIIB phosphocysteine relay and couples transfer to fructose with translocation through EIIC.

Part 4: fructose 1-phosphate conversion to fructose 1,6-bisphosphate
Fructose 1-phosphate phosphorylationReactionfructose_1_phosphate_kinase_reaction

Annotons

FruK 1-phosphofructokinase activity
fruk_activity
Participant: Family: 1-phosphofructokinase family
Family:
1-phosphofructokinase familyPANTHER:PTHR46566:SF5
Representative Members: FruK (Pseudomonas putida KT2440)UniProtKB:Q88PQ4 FruK (Escherichia coli K-12)UniProtKB:P0AEW9

Function

1-phosphofructokinase activityGO:0008662
Substrates: beta-D-fructose 1-phosphate ATP
Products: beta-D-fructose 1,6-bisphosphate ADP proton

This is EC 2.7.1.56 / RHEA:14213.