gmhB encodes D-glycero-beta-D-manno-heptose-1,7-bisphosphate 7-phosphatase for ADP-heptose and LPS core biosynthesis.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Cytoplasm is expected context for GmhB but not the defining activity. Reason: The core function is the HBP phosphatase reaction in heptose/LPS precursor biosynthesis. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm file:PSEPK/gmhB/gmhB-goa.tsv GO:0005737 cytoplasm file:PSEPK/gmhB/gmhB-deep-research-falcon.md This strongly implies that GmhB acts in the **cytosolic** compartment where these metabolites are made and processed, with downstream glycosyltransfer steps contributing to envelope assembly. |
| GO:0005975 carbohydrate metabolic process | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Carbohydrate metabolic process is too broad for GmhB. Reason: GO:0009244 lipopolysaccharide core region biosynthetic process is the accepted, endpoint-neutral process anchor and is more specific than this generic carbohydrate-metabolism term. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt ADP-L-glycero-beta-D-manno-heptose biosynthesis file:PSEPK/gmhB/gmhB-goa.tsv GO:0005975 carbohydrate metabolic process file:PSEPK/gmhB/gmhB-deep-research-falcon.md GmhB occupies the third step of the conserved five-step ADP-heptose biosynthesis pathway supplying heptose for LPS inner-core assembly |
| GO:0016791 phosphatase activity | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Phosphatase activity is a broad parent of the exact heptose-bisphosphate phosphatase activity. Reason: GO:0034200 captures the substrate and reaction position and should be used for core function. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt removing the phosphate group at the C-7 position file:PSEPK/gmhB/gmhB-goa.tsv GO:0016791 phosphatase activity file:PSEPK/gmhB/gmhB-deep-research-falcon.md Supports annotation of Q88RS0 as an HBP 7-phosphatase rather than a generic phosphatase; consistent with UniProt name for PP_0059. |
| GO:0034200 D-glycero-beta-D-manno-heptose 1,7-bisphosphate 7-phosphatase activity | IEA GO_REF:0000120 | ACCEPT | Summary: The IEA GO:0034200 row is the exact catalytic function for GmhB. Reason: UniProt assigns EC 3.1.3.82 and describes the beta-HBP 7-phosphatase reaction. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt removing the phosphate group at the C-7 position file:PSEPK/gmhB/gmhB-goa.tsv GO:0034200 D-glycero-beta-D-manno-heptose 1,7-bisphosphate 7-phosphatase activity file:PSEPK/gmhB/gmhB-deep-research-falcon.md **GmhB** is defined as **D-glycero-Ξ²-D-manno-heptose 1,7-bisphosphate 7-phosphatase**, i.e., an enzyme that **removes the 7-phosphate from HBP** to produce **heptose-1-phosphate (HMP/HMP1)**. |
| GO:0009244 lipopolysaccharide core region biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: LPS core region biosynthesis is a direct downstream pathway for the ADP-heptose precursor made by GmhB. Reason: UniProt links GmhB to bacterial outer membrane LPS core biosynthesis. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt LPS core biosynthesis file:PSEPK/gmhB/gmhB-goa.tsv GO:0009244 lipopolysaccharide core region biosynthetic process file:PSEPK/gmhB/gmhB-deep-research-falcon.md Thus, GmhB is best annotated as an enzyme of **LPS inner-core heptose donor biosynthesis**, rather than a signaling enzyme. |
| GO:0097171 ADP-L-glycero-beta-D-manno-heptose biosynthetic process | IEA GO_REF:0000041 | UNDECIDED | Summary: UniPathway places GmhB in the canonical L,D-heptose route, but the KT2440 stereochemical endpoint is unresolved. Reason: GmhB securely produces D-glycero-beta-D-manno-heptose 1-phosphate, but no HldD ortholog is resolved in KT2440. Until the inner-core heptose stereochemistry or a non-orthologous epimerase is established, the process term's L,D endpoint cannot be accepted for this strain. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt ADP-L-glycero-beta-D-manno-heptose from D- file:PSEPK/gmhB/gmhB-goa.tsv GO:0097171 ADP-L-glycero-beta-D-manno-heptose biosynthetic process file:PSEPK/gmhB/gmhB-deep-research-falcon.md GmhB occupies the third step of the conserved five-step ADP-heptose biosynthesis pathway supplying heptose for LPS inner-core assembly file:projects/P_PUTIDA/deep-research/PSEPK__adp-heptose-biosynthesis__ppu00541-deep-research-openscientist.md The final step β the ADP-L-glycero-D-manno-heptose-6-epimerase HldD/GmhD |
| GO:0034200 D-glycero-beta-D-manno-heptose 1,7-bisphosphate 7-phosphatase activity | EXP PMID:25848029 Panoramic view of a superfamily of phosphatases through subs... | ACCEPT | Summary: The EXP GO:0034200 row experimentally supports the exact GmhB catalytic function. Reason: The curated UniProt entry cites PMID:25848029 for the beta-HBP 7-phosphatase reaction. Supporting Evidence: file:PSEPK/gmhB/gmhB-uniprot.txt EC=3.1.3.82 file:PSEPK/gmhB/gmhB-goa.tsv GO:0034200 D-glycero-beta-D-manno-heptose 1,7-bisphosphate 7-phosphatase activity |
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Download this section (compressed HTML)Q: Does KT2440 GmhB prefer Mg(2+) or alternative metals under physiological conditions?
Experiment: Measure purified GmhB activity against beta-HBP with Mg(2), Zn(2), and other divalent metals and test LPS core defects in a gmhB knockout.
Type: enzyme cofactor panel and LPS profiling
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