Conserved kgu-operon protein with an IolE/XylA/MocC-like isomerase fold. KguE contributes to efficient 2-ketogluconate utilization in Pseudomonas, but its substrate and reaction are unresolved. PP_3376/KguD, not KguE, is the supported candidate for reduction of 2-dehydro-6-phosphogluconate to 6-phosphogluconate.
Definition: The chemical reactions and pathways resulting in the breakdown of 2-dehydro-D-gluconate, including its conversion to 6-phospho-D-gluconate.
Justification: KguE is genetically required for efficient 2-dehydro-D-gluconate use even though its reaction is unresolved; GO:0019521 does not distinguish this substrate-specific pathway.
Parent term: monocarboxylic acid catabolic process
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0008114 phosphogluconate 2-dehydrogenase activity | IEA GO_REF:0000003 | REMOVE | Summary: The annotation is an EC mapping attached to an unreviewed epimerase product string, while KguE chemistry remains experimentally unresolved. Reason: Direct pathway order identifies KguD as the reductase; KguE should not receive the same exact activity without biochemical evidence. The fold also rules it out: every signature places KguE in the metal-dependent xylose-isomerase-like TIM barrel family (IPR050312, Gene3D 3.20.20.150, SSF51658), with no Rossmann NAD(P)-binding domain, whereas EC 1.1.1.43 is a Rossmann-fold dehydrogenase reaction. An independent OpenScientist run found no oxidoreductase among the reviewed members of IPR050312. Supporting Evidence: PMID:39770733 However, the reaction KguE exactly catalyzes remains to be studied. file:PSEPK/kguE/kguE-uniprot.txt IPR050312; IolE/XylAMocC-like. file:PSEPK/kguE/kguE-hypotheses/function-hypothesis-go-0008114/openscientist.md zero oxidoreductases** — the family is exclusively EC class 4 (lyases/dehydratases) and class 5 (isomerases/epimerases) |
| GO:0019521 D-gluconate metabolic process | ISS | NEW | Summary: Cross-species deletion and complementation show that KguE contributes to 2-ketogluconate utilization despite unresolved chemistry. Reason: The process annotation captures the demonstrated pathway role without inventing a molecular function. Supporting Evidence: PMID:39770733 This study proved for the first time that KguE did participate in 2KGA metabolism in Pseudomonas. |
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Download this section (compressed HTML)Q: Which metabolite and stereochemical transformation, if any, is catalyzed by KT2440 KguE?
Experiment: Purify Q88HH8 and assay 2-ketogluconate-pathway intermediates, paired with KT2440 deletion, complementation, and metabolomics.
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Download this section (compressed HTML)The requested OpenScientist run finished without leaving a final gene report, so this
manual note records the evidence used for curation. Cross-species knockout and
complementation show that KguE participates in 2KGA utilization, but the same paper
states, "However, the reaction KguE exactly catalyzes remains to be studied"
PMID:39770733. The EC 1.1.1.43-derived GO:0008114 annotation is therefore removed;
PP_3376/KguD occupies the terminal reductase position in the ordered pathway.
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