D-galactonate degradation

MetaCyc:GALACTCAT-PWY

The complete three-step MetaCyc D-galactonate pathway dehydrates D-galactonate, phosphorylates the resulting 2-dehydro-3-deoxy-D-galactonate with ATP, and cleaves the phosphorylated intermediate to D-glyceraldehyde 3-phosphate and pyruvate. The scope is E. coli K-12: native protein annotations refer to MG1655, while modern growth and transcription experiments used BW25113 derivatives. Current reviewed DgoD and DgoA sequences correct an older predicted gene fusion. DgoD and DgoK catalytic assignments are retained as reviewed annotations supported by native pathway curation and genetic physiology; DgoA also has purified-enzyme and crystal evidence. Functional enzyme edges do not imply isolated-monomer sufficiency: DgoA is homotrimeric. DgoD magnesium binding is annotated by similarity. DgoR represses the dgo operon, and D-galactonate relieves its DNA binding under the tested conditions. Later recombinant-protein work supports a divalent-metal requirement for effector binding without identifying a unique physiological metal. The selected aldolase direction is catabolic despite its reversible native reaction. Uptake, upstream D-galactose oxidation, galactitol utilization and downstream glyceraldehyde-phosphate metabolism lie outside this exact pathway boundary.

Pathway type

d galactonate degradation

Organism scope

Escherichia coli K-12 NCBITaxon:83333

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Pathway network

19 nodes · 27 asserted directed edges

Arrows show recorded subject → object relationships, not necessarily metabolic flow. Select a node for details or an arrow for evidence. Scroll, zoom or find a node to explore.

Reaction / activity
Chemical / cofactor
Protein / complex
Taxon
Pathway
Solid arrow: mechanistic relation
Dashed arrow: membership, location or cofactor relation

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Components and activities

Declared biological components and source reaction directions
Node	Kind or role	Source direction
Escherichia coli K-12 `NCBITaxon:83333`	taxon
D-galactonate `CHEBI:12931`	small molecule
pyruvate `CHEBI:15361`	small molecule
water `CHEBI:15377`	small molecule
hydron `CHEBI:15378`	small molecule
magnesium(2+) `CHEBI:18420`	cofactor
ATP(4-) `CHEBI:30616`	small molecule
ADP(3-) `CHEBI:456216`	small molecule
2-dehydro-3-deoxy-D-galactonate `CHEBI:57989`	small molecule
6-phosphonato-2-dehydro-3-deoxy-D-galactate(3-) `CHEBI:58298`	small molecule
D-glyceraldehyde 3-phosphate(2-) `CHEBI:59776`	small molecule
D-galactonate dehydratase `UniProtKB:Q6BF17`	protein
2-dehydro-3-deoxygalactonokinase `UniProtKB:P31459`	protein
2-dehydro-3-deoxy-6-phosphogalactonate aldolase `UniProtKB:Q6BF16`	protein
Galactonate operon transcriptional repressor `UniProtKB:P31460`	protein
D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	molecular activity	left to right
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	molecular activity	left to right
2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	molecular activity	left to right

Mechanistic edges

Mechanistic edges and their cited evidence
Subject	Predicate and description	Object	Evidence
D-galactonate `CHEBI:12931`	consumes	D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	RHEA:18650 Source assertion: RHEA:18650 assigns CHEBI:12931 to its substrates with coefficient 1. Source location `http://rdf.rhea-db.org/18650 rh:substrates http://rdf.rhea-db.org/18649_L; http://rdf.rhea-db.org/18649_L rh:contains1 http://rdf.rhea-db.org/Participant_18649_compound_4453; http://rdf.rhea-db.org/Participant_18649_compound_4453 rh:compound http://rdf.rhea-db.org/Compound_4453; http://rdf.rhea-db.org/Compound_4453 rh:chebi http://purl.obolibrary.org/obo/CHEBI_12931`
D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	produces	2-dehydro-3-deoxy-D-galactonate `CHEBI:57989`	RHEA:18650 Source assertion: RHEA:18650 assigns CHEBI:57989 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/18650 rh:products http://rdf.rhea-db.org/18649_R; http://rdf.rhea-db.org/18649_R rh:contains1 http://rdf.rhea-db.org/Participant_18649_compound_2839; http://rdf.rhea-db.org/Participant_18649_compound_2839 rh:compound http://rdf.rhea-db.org/Compound_2839; http://rdf.rhea-db.org/Compound_2839 rh:chebi http://purl.obolibrary.org/obo/CHEBI_57989`
D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	produces	water `CHEBI:15377`	RHEA:18650 Source assertion: RHEA:18650 assigns CHEBI:15377 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/18650 rh:products http://rdf.rhea-db.org/18649_R; http://rdf.rhea-db.org/18649_R rh:contains1 http://rdf.rhea-db.org/Participant_18649_compound_1283; http://rdf.rhea-db.org/Participant_18649_compound_1283 rh:compound http://rdf.rhea-db.org/Compound_1283; http://rdf.rhea-db.org/Compound_1283 rh:chebi http://purl.obolibrary.org/obo/CHEBI_15377`
2-dehydro-3-deoxy-D-galactonate `CHEBI:57989`	consumes	2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	RHEA:16526 Source assertion: RHEA:16526 assigns CHEBI:57989 to its substrates with coefficient 1. Source location `http://rdf.rhea-db.org/16526 rh:substrates http://rdf.rhea-db.org/16525_L; http://rdf.rhea-db.org/16525_L rh:contains1 http://rdf.rhea-db.org/Participant_16525_compound_2839; http://rdf.rhea-db.org/Participant_16525_compound_2839 rh:compound http://rdf.rhea-db.org/Compound_2839; http://rdf.rhea-db.org/Compound_2839 rh:chebi http://purl.obolibrary.org/obo/CHEBI_57989`
ATP(4-) `CHEBI:30616`	consumes	2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	RHEA:16526 Source assertion: RHEA:16526 assigns CHEBI:30616 to its substrates with coefficient 1. Source location `http://rdf.rhea-db.org/16526 rh:substrates http://rdf.rhea-db.org/16525_L; http://rdf.rhea-db.org/16525_L rh:contains1 http://rdf.rhea-db.org/Participant_16525_compound_6372; http://rdf.rhea-db.org/Participant_16525_compound_6372 rh:compound http://rdf.rhea-db.org/Compound_6372; http://rdf.rhea-db.org/Compound_6372 rh:chebi http://purl.obolibrary.org/obo/CHEBI_30616`
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	produces	6-phosphonato-2-dehydro-3-deoxy-D-galactate(3-) `CHEBI:58298`	RHEA:16526 Source assertion: RHEA:16526 assigns CHEBI:58298 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/16526 rh:products http://rdf.rhea-db.org/16525_R; http://rdf.rhea-db.org/16525_R rh:contains1 http://rdf.rhea-db.org/Participant_16525_compound_3333; http://rdf.rhea-db.org/Participant_16525_compound_3333 rh:compound http://rdf.rhea-db.org/Compound_3333; http://rdf.rhea-db.org/Compound_3333 rh:chebi http://purl.obolibrary.org/obo/CHEBI_58298`
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	produces	ADP(3-) `CHEBI:456216`	RHEA:16526 Source assertion: RHEA:16526 assigns CHEBI:456216 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/16526 rh:products http://rdf.rhea-db.org/16525_R; http://rdf.rhea-db.org/16525_R rh:contains1 http://rdf.rhea-db.org/Participant_16525_compound_2710; http://rdf.rhea-db.org/Participant_16525_compound_2710 rh:compound http://rdf.rhea-db.org/Compound_2710; http://rdf.rhea-db.org/Compound_2710 rh:chebi http://purl.obolibrary.org/obo/CHEBI_456216`
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	produces	hydron `CHEBI:15378`	RHEA:16526 Source assertion: RHEA:16526 assigns CHEBI:15378 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/16526 rh:products http://rdf.rhea-db.org/16525_R; http://rdf.rhea-db.org/16525_R rh:contains1 http://rdf.rhea-db.org/Participant_16525_compound_3249; http://rdf.rhea-db.org/Participant_16525_compound_3249 rh:compound http://rdf.rhea-db.org/Compound_3249; http://rdf.rhea-db.org/Compound_3249 rh:chebi http://purl.obolibrary.org/obo/CHEBI_15378`
6-phosphonato-2-dehydro-3-deoxy-D-galactate(3-) `CHEBI:58298`	consumes	2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	RHEA:24465 Source assertion: RHEA:24465 assigns CHEBI:58298 to its substrates with coefficient 1. Source location `http://rdf.rhea-db.org/24465 rh:substrates http://rdf.rhea-db.org/24464_L; http://rdf.rhea-db.org/24464_L rh:contains1 http://rdf.rhea-db.org/Participant_24464_compound_3333; http://rdf.rhea-db.org/Participant_24464_compound_3333 rh:compound http://rdf.rhea-db.org/Compound_3333; http://rdf.rhea-db.org/Compound_3333 rh:chebi http://purl.obolibrary.org/obo/CHEBI_58298`
2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	produces	D-glyceraldehyde 3-phosphate(2-) `CHEBI:59776`	RHEA:24465 Source assertion: RHEA:24465 assigns CHEBI:59776 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/24465 rh:products http://rdf.rhea-db.org/24464_R; http://rdf.rhea-db.org/24464_R rh:contains1 http://rdf.rhea-db.org/Participant_24464_compound_6062; http://rdf.rhea-db.org/Participant_24464_compound_6062 rh:compound http://rdf.rhea-db.org/Compound_6062; http://rdf.rhea-db.org/Compound_6062 rh:chebi http://purl.obolibrary.org/obo/CHEBI_59776`
2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	produces	pyruvate `CHEBI:15361`	RHEA:24465 Source assertion: RHEA:24465 assigns CHEBI:15361 to its products with coefficient 1. Source location `http://rdf.rhea-db.org/24465 rh:products http://rdf.rhea-db.org/24464_R; http://rdf.rhea-db.org/24464_R rh:contains1 http://rdf.rhea-db.org/Participant_24464_compound_3719; http://rdf.rhea-db.org/Participant_24464_compound_3719 rh:compound http://rdf.rhea-db.org/Compound_3719; http://rdf.rhea-db.org/Compound_3719 rh:chebi http://purl.obolibrary.org/obo/CHEBI_15361`
D-galactonate dehydratase `UniProtKB:Q6BF17`	enables Functional enzyme assignment; no physical assembly stoichiometry is asserted.	D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	UniProtKB:Q6BF17 Source assertion: The reviewed Q6BF17 catalytic-activity annotation assigns RHEA:18649; this specifies the gene product function, not isolated-monomer sufficiency. Source location `comments[1].reaction.name/reactionCrossReferences; organism.taxonId; genes` MetaCyc:GALACTONATE-DEHYDRATASE-MONOMER Source assertion: The native MG1655 protein frame identifies UniProt Q6BF17 and links its enzymatic reaction to GALACTONDEHYDRAT-RXN. Source location `Protein[@frameid="GALACTONATE-DEHYDRATASE-MONOMER"]/dblink[dblink-db="UNIPROT"]; species/Organism[@frameid="TAX-511145"]; catalyzes/Enzymatic-Reaction/reaction/Reaction`
2-dehydro-3-deoxygalactonokinase `UniProtKB:P31459`	enables Functional enzyme assignment; no physical assembly stoichiometry is asserted.	2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	UniProtKB:P31459 Source assertion: The reviewed P31459 catalytic-activity annotation assigns RHEA:16525; this specifies the gene product function, not isolated-monomer sufficiency. Source location `comments[0].reaction.name/reactionCrossReferences; organism.taxonId; genes` MetaCyc:DEHYDDEOXGALACTKIN-MONOMER Source assertion: The native MG1655 protein frame identifies UniProt P31459 and links its enzymatic reaction to DEHYDDEOXGALACTKIN-RXN. Source location `Protein[@frameid="DEHYDDEOXGALACTKIN-MONOMER"]/dblink[dblink-db="UNIPROT"]; species/Organism[@frameid="TAX-511145"]; catalyzes/Enzymatic-Reaction/reaction/Reaction`
2-dehydro-3-deoxy-6-phosphogalactonate aldolase `UniProtKB:Q6BF16`	enables Functional enzyme assignment; the active protein is described as a homotrimer, without a separately identified physical-complex node.	2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	UniProtKB:Q6BF16 Source assertion: The reviewed Q6BF16 catalytic-activity annotation assigns RHEA:24464; this specifies the gene product function, not isolated-monomer sufficiency. Source location `comments[1].reaction.name/reactionCrossReferences; organism.taxonId; genes` MetaCyc:DEHYDDEOXPHOSGALACT-ALDOL-MONOMER Source assertion: The native MG1655 protein frame identifies UniProt Q6BF16 and links its enzymatic reaction to DEHYDDEOXPHOSGALACT-ALDOL-RXN. Source location `Protein[@frameid="DEHYDDEOXPHOSGALACT-ALDOL-MONOMER"]/dblink[dblink-db="UNIPROT"]; species/Organism[@frameid="TAX-511145"]; catalyzes/Enzymatic-Reaction/reaction/Reaction` PMID:17981470 Source assertion: Purified recombinant E. coli KDPGal aldolase cleaved KDPGal; the structure and solution description support a homotrimer. Expression in an eda-deficient host reduced KDPG-aldolase contamination. Source location `PMC3326530 Results #P5, #P6 and #P10; Introduction #P4; Methods #P22-#P25 and #P33`
D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	part_of	`MetaCyc:GALACTCAT-PWY`	MetaCyc:GALACTCAT-PWY Source assertion: The complete native pathway includes GALACTONDEHYDRAT-RXN in its reaction list and selects L2R in its pathway layout. Source location `Pathway[@frameid="GALACTCAT-PWY"]/reaction-list/Reaction[@frameid="GALACTONDEHYDRAT-RXN"]; reaction-layout[Reaction/@frameid="GALACTONDEHYDRAT-RXN"]/direction` MetaCyc:GALACTONDEHYDRAT-RXN Source assertion: The native reaction cross-references RHEA:18650; its reaction-direction is LEFT-TO-RIGHT. Source location `Reaction/dblink[dblink-db="RHEA"]; reaction-direction; left/Compound; right/Compound` RHEA:18650 Source assertion: Rhea master 18649 explicitly contains directed member 18650; the selected substrates and products implement catabolic left-to-right chemistry. Source location `http://rdf.rhea-db.org/18649 rh:directionalReaction http://rdf.rhea-db.org/18650; http://rdf.rhea-db.org/18650 rh:substrates http://rdf.rhea-db.org/18649_L; rh:products http://rdf.rhea-db.org/18649_R; rh:equation`
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	part_of	`MetaCyc:GALACTCAT-PWY`	MetaCyc:GALACTCAT-PWY Source assertion: The complete native pathway includes DEHYDDEOXGALACTKIN-RXN in its reaction list and selects L2R in its pathway layout. Source location `Pathway[@frameid="GALACTCAT-PWY"]/reaction-list/Reaction[@frameid="DEHYDDEOXGALACTKIN-RXN"]; reaction-layout[Reaction/@frameid="DEHYDDEOXGALACTKIN-RXN"]/direction` MetaCyc:DEHYDDEOXGALACTKIN-RXN Source assertion: The native reaction cross-references RHEA:16526; its reaction-direction is LEFT-TO-RIGHT. Source location `Reaction/dblink[dblink-db="RHEA"]; reaction-direction; left/Compound; right/Compound` RHEA:16526 Source assertion: Rhea master 16525 explicitly contains directed member 16526; the selected substrates and products implement catabolic left-to-right chemistry. Source location `http://rdf.rhea-db.org/16525 rh:directionalReaction http://rdf.rhea-db.org/16526; http://rdf.rhea-db.org/16526 rh:substrates http://rdf.rhea-db.org/16525_L; rh:products http://rdf.rhea-db.org/16525_R; rh:equation`
2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	part_of	`MetaCyc:GALACTCAT-PWY`	MetaCyc:GALACTCAT-PWY Source assertion: The complete native pathway includes DEHYDDEOXPHOSGALACT-ALDOL-RXN in its reaction list and selects L2R in its pathway layout. Source location `Pathway[@frameid="GALACTCAT-PWY"]/reaction-list/Reaction[@frameid="DEHYDDEOXPHOSGALACT-ALDOL-RXN"]; reaction-layout[Reaction/@frameid="DEHYDDEOXPHOSGALACT-ALDOL-RXN"]/direction` MetaCyc:DEHYDDEOXPHOSGALACT-ALDOL-RXN Source assertion: The native reaction cross-references RHEA:24467; its reaction-direction is REVERSIBLE. Source location `Reaction/dblink[dblink-db="RHEA"]; reaction-direction; left/Compound; right/Compound` RHEA:24465 Source assertion: Rhea master 24464 explicitly contains directed member 24465; the selected substrates and products implement catabolic left-to-right chemistry. Source location `http://rdf.rhea-db.org/24464 rh:directionalReaction http://rdf.rhea-db.org/24465; http://rdf.rhea-db.org/24465 rh:substrates http://rdf.rhea-db.org/24464_L; rh:products http://rdf.rhea-db.org/24464_R; rh:equation`
D-galactonate dehydratase `UniProtKB:Q6BF17`	part_of	Escherichia coli K-12 `NCBITaxon:83333`	UniProtKB:Q6BF17 Source assertion: The reviewed Q6BF17 entry assigns the protein to Escherichia coli strain K12, taxon 83333. Source location `organism.scientificName; organism.taxonId; genes`
2-dehydro-3-deoxygalactonokinase `UniProtKB:P31459`	part_of	Escherichia coli K-12 `NCBITaxon:83333`	UniProtKB:P31459 Source assertion: The reviewed P31459 entry assigns the protein to Escherichia coli strain K12, taxon 83333. Source location `organism.scientificName; organism.taxonId; genes`
2-dehydro-3-deoxy-6-phosphogalactonate aldolase `UniProtKB:Q6BF16`	part_of	Escherichia coli K-12 `NCBITaxon:83333`	UniProtKB:Q6BF16 Source assertion: The reviewed Q6BF16 entry assigns the protein to Escherichia coli strain K12, taxon 83333. Source location `organism.scientificName; organism.taxonId; genes`
Galactonate operon transcriptional repressor `UniProtKB:P31460`	part_of	Escherichia coli K-12 `NCBITaxon:83333`	UniProtKB:P31460 Source assertion: The reviewed P31460 entry assigns the protein to Escherichia coli strain K12, taxon 83333. Source location `organism.scientificName; organism.taxonId; genes`
D-galactonate dehydratase `UniProtKB:Q6BF17`	has_cofactor Magnesium assignment by similarity; no physical oligomer stoichiometry inferred.	magnesium(2+) `CHEBI:18420`	UniProtKB:Q6BF17 Source assertion: DgoD is annotated to bind one Mg(2+) per subunit by similarity (ECO:0000250); this is not a direct K-12 metal-binding measurement. Source location `comments[2].cofactors[0].cofactorCrossReference/evidences; comments[2].note.texts[0]`
D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O `RHEA:18650`	precedes	2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	MetaCyc:GALACTCAT-PWY Source assertion: Native pathway ordering places GALACTONDEHYDRAT-RXN before DEHYDDEOXGALACTKIN-RXN. Source location `Pathway/reaction-ordering[Reaction/@frameid="DEHYDDEOXGALACTKIN-RXN"]/predecessor-reactions/Reaction[@frameid="GALACTONDEHYDRAT-RXN"]` RHEA:18650 Source assertion: In the selected Rhea chemistry the preceding reaction produces the retained shared intermediate CHEBI:57989. Source location `http://rdf.rhea-db.org/18650 rh:products http://rdf.rhea-db.org/18649_R; side rh:contains1 / participant rh:compound / compound rh:chebi` RHEA:16526 Source assertion: The subsequent selected Rhea reaction consumes CHEBI:57989, connecting the native steps without adding a transport reaction. Source location `http://rdf.rhea-db.org/16526 rh:substrates http://rdf.rhea-db.org/16525_L; side rh:contains1 / participant rh:compound / compound rh:chebi`
2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) `RHEA:16526`	precedes	2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate `RHEA:24465`	MetaCyc:GALACTCAT-PWY Source assertion: Native pathway ordering places DEHYDDEOXGALACTKIN-RXN before DEHYDDEOXPHOSGALACT-ALDOL-RXN. Source location `Pathway/reaction-ordering[Reaction/@frameid="DEHYDDEOXPHOSGALACT-ALDOL-RXN"]/predecessor-reactions/Reaction[@frameid="DEHYDDEOXGALACTKIN-RXN"]` RHEA:16526 Source assertion: In the selected Rhea chemistry the preceding reaction produces the retained shared intermediate CHEBI:58298. Source location `http://rdf.rhea-db.org/16526 rh:products http://rdf.rhea-db.org/16525_R; side rh:contains1 / participant rh:compound / compound rh:chebi` RHEA:24465 Source assertion: The subsequent selected Rhea reaction consumes CHEBI:58298, connecting the native steps without adding a transport reaction. Source location `http://rdf.rhea-db.org/24465 rh:substrates http://rdf.rhea-db.org/24464_L; side rh:contains1 / participant rh:compound / compound rh:chebi`
`MetaCyc:GALACTCAT-PWY`	part_of	Escherichia coli K-12 `NCBITaxon:83333`	PMID:30455279 Source assertion: BW25113-derived dgoD, dgoK and dgoA deletions failed to grow on D-galactonate while growing on glucose. These genetic results support K-12 pathway physiology, not purified-enzyme assignments. Source location `PMC6351737 Results #s2.1, Fig. 1C; Materials and Methods #s4.3, Table 1` PMID:211976 Source assertion: The publisher abstract reports K-12 mutants lacking individual D-galactonate pathway activities or all three, with linked structural genes and inducible enzyme activities. Source location `Publisher Abstract, numbered statements 1, 2 and 6; abstract-only access`
Galactonate operon transcriptional repressor `UniProtKB:P31460`	regulates Negative transcriptional regulation of the operon encoding the pathway, not direct inhibition of catalytic proteins.	`MetaCyc:GALACTCAT-PWY`	UniProtKB:P31460 Source assertion: Reviewed DgoR annotation describes repression of the dgoRKADT operon through binding two inverted repeats in its cis-acting element. Source location `comments[0] FUNCTION` PMID:30455279 Source assertion: DgoR loss increased dgo transcription; purified DgoR bound the upstream cis-acting element, with IR1 and IR2 needed for binding and repression. Source location `PMC6351737 Results #s2.1 and #s2.4; Fig. 1F and Fig. 4; Methods #s4.3 and #s4.9`
D-galactonate `CHEBI:12931`	inhibits Inhibition of repressor DNA binding under the tested conditions; divalent-metal-dependent effector response, without assigning a unique physiological metal or catalytic consumption of the effector.	Galactonate operon transcriptional repressor `UniProtKB:P31460`	PMID:30455279 Source assertion: D-galactonate reduced DgoR binding to its target DNA in vitro and changed its proteolysis pattern; the EMSA buffer contained MgCl2. Source location `PMC6351737 Results #s2.7, Fig. 8A-C; Materials and Methods #s4.9 and #s4.12` PMID:33224125 Source assertion: After EDTA treatment, D-galactonate with Zn2+, Ca2+ or Mg2+ reduced DgoR-DNA complex stability. Metal depletion did not directly abolish DNA binding. Source location `PMC7674646 Results #S3.SS3, Fig. 6; Discussion #S4`

References

MetaCyc:GALACTCAT-PWY D-galactonate degradation: complete native pathway (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
MetaCyc:GALACTONDEHYDRAT-RXN Native GALACTONDEHYDRAT-RXN definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
MetaCyc:GALACTONATE-DEHYDRATASE-MONOMER Native GALACTONATE-DEHYDRATASE-MONOMER definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
RHEA:18650 D-galactonate => 2-dehydro-3-deoxy-D-galactonate + H2O (source version: Rhea 142, released 2026-09-02; digest covers the complete compressed RDF)
MetaCyc:DEHYDDEOXGALACTKIN-RXN Native DEHYDDEOXGALACTKIN-RXN definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
MetaCyc:DEHYDDEOXGALACTKIN-MONOMER Native DEHYDDEOXGALACTKIN-MONOMER definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
RHEA:16526 2-dehydro-3-deoxy-D-galactonate + ATP => 2-dehydro-3-deoxy-6-phospho-D-galactonate + ADP + H(+) (source version: Rhea 142, released 2026-09-02; digest covers the complete compressed RDF)
MetaCyc:DEHYDDEOXPHOSGALACT-ALDOL-RXN Native DEHYDDEOXPHOSGALACT-ALDOL-RXN definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
MetaCyc:DEHYDDEOXPHOSGALACT-ALDOL-MONOMER Native DEHYDDEOXPHOSGALACT-ALDOL-MONOMER definition (source version: MetaCyc 22.5; complete native XML retrieved 2026-10-11 UTC)
RHEA:24465 2-dehydro-3-deoxy-6-phospho-D-galactonate => D-glyceraldehyde 3-phosphate + pyruvate (source version: Rhea 142, released 2026-09-02; digest covers the complete compressed RDF)
UniProtKB:Q6BF17 Reviewed E. coli K-12 D-galactonate dehydratase (source version: UniProt 2026_03; complete JSON retrieved 2026-10-11 UTC; release confirmed by response header)
UniProtKB:P31459 Reviewed E. coli K-12 2-dehydro-3-deoxygalactonokinase (source version: UniProt 2026_03; complete JSON retrieved 2026-10-11 UTC; release confirmed by response header)
UniProtKB:Q6BF16 Reviewed E. coli K-12 2-dehydro-3-deoxy-6-phosphogalactonate aldolase (source version: UniProt 2026_03; complete JSON retrieved 2026-10-11 UTC; release confirmed by response header)
UniProtKB:P31460 Reviewed E. coli K-12 Galactonate operon transcriptional repressor (source version: UniProt 2026_03; complete JSON retrieved 2026-10-11 UTC; release confirmed by response header)
PMID:30455279 Molecular and Functional Insights into the Regulation of D-Galactonate Metabolism by the Transcriptional Regulator DgoR in Escherichia coli. (source version: Complete primary HTML; inspected Results and Methods; retrieved 2026-10-11 UTC)
PMID:17981470 Characterization and crystal structure of Escherichia coli KDPGal aldolase. (source version: Complete primary HTML; inspected Results and Methods; retrieved 2026-10-11 UTC)
PMID:33224125 Structural and Functional Analyses of the Transcription Repressor DgoR From Escherichia coli Reveal a Divalent Metal-Containing D-Galactonate Binding Pocket. (source version: Complete primary HTML; inspected Results and Methods; retrieved 2026-10-11 UTC)
PMID:211976 The utilisation of D-galactonate and D-2-oxo-3-deoxygalactonate by Escherichia coli K-12. (source version: Publisher abstract only; numbered statements 1-6 inspected; full article unavailable; retrieved 2026-10-11 UTC)

Curation history

2026-10-11T04:37:08Z Codex
- CREATE — Add the complete three-reaction D-galactonate degradation pathway.
  Retain native pathway boundaries, current balanced Rhea chemistry, DgoD/K/A activity associations and conditional DgoR evidence. Exact source dossiers and author checks are in research/pathway_additions/2026-10-11-next-189. Independent scientific reviews and shared validation are recorded separately.
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2026-10-11T04:47:16Z Codex
- EDIT — Correct the primary figure locators for galactonate physiology and DgoR effector evidence
  Corrected the PMID:30455279 growth locator from Figure 1B to Figure 1C and the effector-binding/proteolysis locator from Figure 7 to Figure 8A-C against the original PMC6351737 Results and captions. Scientific assertions, three reactions and 27 edges are unchanged. Independent initial review 20261011T043907Z-galactonate-initial-independent-review remains immutable; final replay and successor review are recorded separately.
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