UDP-glucose and UDP-galactose biosynthesis

Species-neutral bacterial module for production of UDP-glucose from glucose 6-phosphate and its reversible interconversion with UDP-galactose. The module contains phosphoglucomutase, UTP--glucose-1-phosphate uridylyltransferase, and UDP-glucose 4-epimerase reactions. It supplies activated hexoses to multiple downstream glycoconjugate and storage-polymer pathways; those consuming pathways are outside this module.

MODULE:udp_glucose_and_udp_galactose_biosynthesisDRAFTCONCRETEMetabolic Pathwaymodules/udp_glucose_and_udp_galactose_biosynthesis.yaml
UDP-alpha-D-glucose metabolic processGO:0006011 galactose metabolic processGO:0006012
file:PSEPK/pgm/pgm-uniprot.txt
UniProtKB entry for PSEPK pgm
Q88GY7 is annotated as phosphoglucomutase EC 5.4.2.2.
file:PSEPK/algC/algC-uniprot.txt
UniProtKB entry for PSEPK algC
Q88C93 is a bifunctional phosphomannomutase/phosphoglucomutase with EC 5.4.2.8 and EC 5.4.2.2.
file:PSEPK/galU/galU-uniprot.txt
UniProtKB entry for PSEPK galU
Q88GA4 is annotated as UTP--glucose-1-phosphate uridylyltransferase EC 2.7.7.9.
file:PSEPK/galE/galE-uniprot.txt
UniProtKB entry for PSEPK galE
Q88I72 is annotated as UDP-glucose 4-epimerase EC 5.1.3.2.

PSEPK Pgm/PP_3578 is the dedicated primary candidate for glucose 1-phosphate formation, while bifunctional AlgC/PP_5288 provides a plausible alternative or backup; their in-vivo flux split has not been measured. CpsG/PP_1777 is excluded because current evidence supports phosphomannomutase rather than phosphoglucomutase activity. Glucose kinase, aldose mutarotation, galactose uptake/catabolism, and downstream polymer assembly are separate modules.

6Nodes
3Parts
1Variant Sets
2Variants
4Annotons
0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✓ present

  • udp_glucose_and_udp_galactose_biosynthesis-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 (4/4 grounded genes reviewed)

4 complete review(s) · 4 with deep research · 0 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
algC Q88C93 ✓ ✓ ✓
galE Q88I72 ✓ ✓ ✓
galU Q88GA4 ✓ ✓ ✓
pgm Q88GY7 ✓ ✓ ✓

Details

Context
bacteriaNCBITaxon:2
UDP-glucose and UDP-galactose biosynthesisMetabolic Pathwayudp_glucose_and_udp_galactose_biosynthesis
UDP-alpha-D-glucose metabolic processGO:0006011 galactose metabolic processGO:0006012
Context
bacteriaNCBITaxon:2
Part 1: glucose 1-phosphate formation
Phosphoglucomutase reactionReactionphosphoglucomutase_step

Alternative enzyme solutions can supply this reaction. A dedicated Pgm or a bifunctional AlgC-type phosphomannomutase/phosphoglucomutase may provide glucose 1-phosphate; both are not universally required.

Variant set: Glucose 1-phosphate enzyme route by phosphoglucomutase enzyme architecture (One Or More)
Dedicated Pgm routeReactiondedicated_pgm_variant

Annotons

Pgm: phosphoglucomutase
pgm_phosphoglucomutase
Participant: Family: bacterial phosphoglucomutase family
Family:
bacterial phosphoglucomutase familyPANTHER:PTHR45745:SF1
Representative Members: PSEPK pgm exemplarUniProtKB:Q88GY7

Function

phosphoglucomutase activityGO:0004614
Substrates: alpha-D-glucose 6-phosphate
Products: alpha-D-glucose 1-phosphate

Provides glucose 1-phosphate from the central glucose 6-phosphate pool.

Bifunctional AlgC routeReactionbifunctional_algc_variant

Annotons

AlgC: phosphoglucomutase
algc_phosphoglucomutase
Participant: Family: bifunctional phosphomannomutase/phosphoglucomutase family
Family:
bifunctional phosphomannomutase/phosphoglucomutase familyPANTHER:PTHR43771:SF2
Representative Members: PSEPK algC exemplarUniProtKB:Q88C93

Function

phosphoglucomutase activityGO:0004614
Substrates: alpha-D-glucose 6-phosphate
Products: alpha-D-glucose 1-phosphate

Provides an alternative bifunctional route to glucose 1-phosphate while also supporting mannose-phosphate metabolism.

Part 2: UDP-glucose formation
UTP--glucose-1-phosphate uridylyltransferase reactionReactiongalu_udp_glucose_step

Annotons

GalU: UTP--glucose-1-phosphate uridylyltransferase
galu_uridylyltransferase
Participant: Family: bacterial UTP--glucose-1-phosphate uridylyltransferase family
Family:
bacterial UTP--glucose-1-phosphate uridylyltransferase familyPANTHER:PTHR43197:SF1
Representative Members: PSEPK galU exemplarUniProtKB:Q88GA4

Function

UTP:glucose-1-phosphate uridylyltransferase activityGO:0003983
Substrates: UTP alpha-D-glucose 1-phosphate
Products: UDP-alpha-D-glucose diphosphate

Processes

UDP-alpha-D-glucose metabolic processGO:0006011

Activates glucose 1-phosphate as UDP-glucose.

Part 3: UDP-galactose formation and interconversion
UDP-glucose 4-epimerase reactionReactiongale_udp_glucose_epimerase_step

Annotons

GalE: UDP-glucose 4-epimerase
gale_udp_glucose_4_epimerase
Participant: Family: UDP-glucose 4-epimerase family
Family:
UDP-glucose 4-epimerase family
Representative Members: PSEPK galE exemplarUniProtKB:Q88I72

Function

UDP-glucose 4-epimerase activityGO:0003978
Substrates: UDP-alpha-D-glucose
Products: UDP-alpha-D-galactose
Cofactors: NAD+

Processes

galactose metabolic processGO:0006012

Reversibly interconverts UDP-glucose and UDP-galactose to supply both activated hexose pools.