PP_2998 encodes a soluble ApbA-fold NAD(P)-dependent oxidoreductase related to ketopantoate reductases. Q88IK1 belongs to a KPR-related PANTHER family distinct from the canonical PanE family. Members of this broader family have divergent alpha-keto-acid substrate preferences, and the native substrate and physiological pathway of the KT2440 protein remain unresolved.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005737 cytoplasm | IEA GO_REF:0000118 | ACCEPT | Summary: Cytoplasmic localization is consistent with this soluble oxidoreductase. Reason: Q88IK1 has a soluble two-domain Rossmann-like/ApbA architecture and no signal peptide or transmembrane segment. Supporting Evidence: file:PSEPK/PP_2998/PP_2998-uniprot.txt DR SUPFAM; SSF51735; NAD(P)-binding Rossmann-fold domains; 1. |
| GO:0008677 2-dehydropantoate 2-reductase activity | IEA GO_REF:0000120 | UNDECIDED | Summary: The family evidence does not resolve ketopantoate as the substrate of Q88IK1. Reason: The annotation is an electronic EC/rule transfer from an ApbA/KPR-related family rather than a direct assay. This family contains proteins assigned as ketopantoate reductases, but the experimentally characterized Pseudomonas member PaKPR2 has lost ketopantoate activity and instead reduces other alpha-keto acids. PP_2998 is not the reciprocal-best KT2440 ortholog of PaKPR2, so that negative result cannot be transferred confidently either. Direct biochemistry or closer orthology is needed. Supporting Evidence: file:PSEPK/PP_2998/PP_2998-uniprot.txt DR InterPro; IPR051402; KPR-Related. file:PSEPK/PP_2998/PP_2998-notes.md The family-level evidence therefore does not resolve Q88IK1 substrate PMID:38962820 resulting in its inactivity toward the natural substrate ketopantoate file:PSEPK/PP_2998/PP_2998-deep-research-openscientist.md No direct experimental data on the *P. putida* protein. |
| GO:0016616 oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor | ISS file:PSEPK/PP_2998/PP_2998-deep-research-openscientist.md | NEW | Summary: This donor and cofactor class captures the supported family-level function without asserting a substrate. Reason: Q88IK1 has the conserved NAD(P)-binding Rossmann-like and ApbA oxidoreductase architecture. GO:0016616 captures the alcohol/oxo-acid redox chemistry and NAD(P) cofactor class while the native alpha-keto-acid substrate remains unknown. Supporting Evidence: file:PSEPK/PP_2998/PP_2998-uniprot.txt DR SUPFAM; SSF51735; NAD(P)-binding Rossmann-fold domains; 1. file:PSEPK/PP_2998/PP_2998-uniprot.txt KW Oxidoreductase {ECO:0000256|ARBA:ARBA00023002, PMID:38962820 active against several important Ξ±-keto-acid substrates |
| GO:0015940 pantothenate biosynthetic process | IEA GO_REF:0000120 | UNDECIDED | Summary: Pathway placement depends on the unresolved ketopantoate-reductase assignment. Reason: The UniPathway annotation is propagated from EC 1.1.1.169. Canonical panE/PP_1351 already satisfies the ketopantoate-reduction step in KT2440, but redundancy remains possible; the available family evidence neither establishes nor excludes a pantothenate-biosynthetic role for Q88IK1. Supporting Evidence: file:PSEPK/PP_2998/PP_2998-notes.md The specific molecular-function and pantothenate-process file:PSEPK/PP_2998/PP_2998-deep-research-openscientist.md The functional assignment, while strong, remains an inference. file:projects/P_PUTIDA/deep-research/PSEPK__coenzyme_a_biosynthesis__ppu00770-deep-research-openscientist.md PP_2325 / PP_2998 substrate specificity is unresolved |
Loading supporting contentβ¦
Download this section (compressed HTML)Q: Does Q88IK1 reduce ketopantoate, and what substrate and pathway dominate in vivo?
Experiment: Purify Q88IK1 and compare ketopantoate reduction with a diverse alpha-keto-acid panel using NADPH and NADH, then test panE and PP_2998 single and double mutants for pantothenate auxotrophy and metabolite changes.
Type: biochemical and genetic analysis
Loading supporting contentβ¦
Download this section (compressed HTML)Loading supporting contentβ¦
Download this section (compressed HTML)Loading supporting contentβ¦
Download this section (compressed HTML)