KdsC is the magnesium-dependent KDO-8-phosphate phosphatase of CMP-KDO biosynthesis. It hydrolyzes KDO-8-phosphate to free KDO, which KdsB then activates for lipopolysaccharide inner-core assembly.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0008781 N-acylneuraminate cytidylyltransferase activity | IEA GO_REF:0000118 | REMOVE | Summary: This TreeGrafter transfer of CMP-sialic acid synthetase activity conflicts with the KdsC phosphatase assignment. Reason: GO:0008781 is defined as "CTP + N-acylneuraminate = diphosphate + CMP-N-acylneuraminate". Q88P96 is a 174-residue HAD-superfamily KdsC (TIGR01670, PIRSF006118) that hydrolyses KDO 8-phosphate and has no cytidylyltransferase domain. PTHR21485 mixes CMAS/NeuA cytidylyltransferases with standalone KdsC phosphatases; the PAINT IBD at PTN000486303 is seeded only by cytidylyltransferases, and no KdsC protein is a leaf of the PANTHER tree, so the TreeGrafter call is an over-propagation to a protein lacking the transferase chemistry. Supporting Evidence: file:PSEPK/kdsC/kdsC-uniprot.txt DR NCBIfam; TIGR01670; KdsC-phosphatas; 1. file:PSEPK/kdsC/kdsC-uniprot.txt Catalyzes the hydrolysis of 3-deoxy-D-manno-octulosonate 8-phosphate (KDO 8-P) to 3-deoxy-D-manno-octulosonate (KDO) and inorganic phosphate |
| GO:0016788 hydrolase activity, acting on ester bonds | IEA GO_REF:0000002 | MODIFY | Summary: KdsC hydrolyses a phosphate ester. Reason: Correct but general; 3-deoxy-manno-octulosonate-8-phosphatase activity (GO:0019143), which the gene also carries, is an is_a descendant. Proposed replacements: 3-deoxy-manno-octulosonate-8-phosphatase activity Supporting Evidence: file:PSEPK/kdsC/kdsC-uniprot.txt Catalyzes the hydrolysis of 3-deoxy-D-manno-octulosonate 8-phosphate (KDO 8-P) to 3-deoxy-D-manno-octulosonate (KDO) and inorganic phosphate |
| GO:0019143 3-deoxy-manno-octulosonate-8-phosphatase activity | IEA GO_REF:0000120 | ACCEPT | Summary: KdsC hydrolyses KDO 8-phosphate to KDO and phosphate. Reason: The PIRNR rule, EC 3.1.3.45/Rhea 11500 and the KdsC-specific TIGR01670 family agree on this activity. Supporting Evidence: file:PSEPK/kdsC/kdsC-uniprot.txt Catalyzes the hydrolysis of 3-deoxy-D-manno-octulosonate 8-phosphate (KDO 8-P) to 3-deoxy-D-manno-octulosonate (KDO) and inorganic phosphate file:PSEPK/kdsC/kdsC-uniprot.txt DR PIRSF; PIRSF006118; KDO8-P_Ptase; 1. |
| GO:0019294 keto-3-deoxy-D-manno-octulosonic acid biosynthetic process | ISS file:PSEPK/kdsC/kdsC-uniprot.txt | NEW | Summary: KdsC produces free KDO, the last step of KDO formation. Reason: KDO 8-phosphate hydrolysis is the final reaction of KDO biosynthesis, as established for the E. coli ortholog YrbI/KdsC; Q88P96 belongs to the same KdsC family (TIGR01670, PIRSF006118). Supporting Evidence: file:PSEPK/kdsC/kdsC-uniprot.txt Catalyzes the hydrolysis of 3-deoxy-D-manno-octulosonate 8-phosphate (KDO 8-P) to 3-deoxy-D-manno-octulosonate (KDO) and inorganic phosphate PMID:12639950 is the last enzyme in the KDO biosynthetic pathway for which the gene has not been identified |
| GO:0009103 lipopolysaccharide biosynthetic process | ISS file:PSEPK/kdsC/kdsC-uniprot.txt | NEW | Summary: KdsC supplies KDO for lipopolysaccharide inner-core assembly. Reason: KDO made by KdsC is activated by KdsB and transferred to lipid A by WaaA; the E. coli kdsC locus is part of the KDO biosynthesis genes required for the LPS inner core. Ortholog inference, not KT2440 evidence. Supporting Evidence: PMID:16765569 Two recently identified genes involved in KDO biosynthesis, kdsD and kdsC file:PSEPK/kdsC/kdsC-uniprot.txt DR NCBIfam; TIGR01670; KdsC-phosphatas; 1. |
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Download this section (compressed HTML)Q: Does KT2440 KdsC provide all KDO-8-phosphate phosphatase activity in vivo?
Experiment: Test KDO-8-phosphate accumulation and LPS defects in a conditional kdsC depletion strain.
Type: targeted metabolomics and LPS profiling
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