AnmK is the ATP-dependent anhydro-N-acetylmuramic acid kinase of peptidoglycan recycling. It opens the 1,6-anhydro ring while phosphorylating anhMurNAc to MurNAc-6-phosphate, which enters the Pseudomonas anabolic recycling route to UDP-MurNAc.
Definition: Catalysis of the ATP-dependent phosphorylation and ring opening of 1,6-anhydro-N-acetyl-beta-muramate to form N-acetyl-D-muramate 6-phosphate, ADP, and a proton.
Justification: EC 2.7.1.170 and Rhea 24952 define a substrate-specific reaction that is currently represented only by a broad phosphotransferase term in GOA.
Parent term: phosphotransferase activity, alcohol group as acceptor
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005524 ATP binding | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: ATP is the phosphate donor for the AnmK reaction. Reason: ATP binding is valid but less informative than the substrate-specific kinase reaction. Supporting Evidence: file:PSEPK/anmK/anmK-uniprot.txt Reaction=1,6-anhydro-N-acetyl-beta-muramate + ATP + H2O |
| GO:0006040 amino sugar metabolic process | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: AnmK converts the amino sugar anhMurNAc to MurNAc-6-phosphate. Reason: The term is true but much broader than peptidoglycan turnover and anhMurNAc metabolism, which capture the biological role more precisely. |
| GO:0009254 peptidoglycan turnover | IEA GO_REF:0000120 | ACCEPT | Summary: AnmK channels an anhydro-muropeptide sugar into recycling. Reason: The reviewed UniProt record and the P. putida pathway study place AnmK in peptidoglycan recycling. Supporting Evidence: file:PSEPK/anmK/anmK-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan recycling. file:PSEPK/anmK/anmK-uniprot.txt Cells lacking this gene accumulate anhMurNAc and |
| GO:0016773 phosphotransferase activity, alcohol group as acceptor | IEA GO_REF:0000120 | ACCEPT | Summary: This is the best available GO term for the AnmK reaction class. Reason: GO lacks a substrate-specific term for EC 2.7.1.170. GO:0016773 correctly captures phosphorylation of an alcohol group and is retained as the core molecular function while the exact AnmK activity is requested below. |
| GO:0097175 1,6-anhydro-N-acetyl-beta-muramic acid catabolic process | IEA GO_REF:0000120 | ACCEPT | Summary: AnmK consumes 1,6-anhydro-MurNAc during cell-wall sugar recovery. Reason: Ring opening and phosphorylation remove anhMurNAc, even though in Pseudomonas the resulting MurNAc-6-phosphate is recycled anabolically rather than cleaved by MurQ. Supporting Evidence: file:PSEPK/anmK/anmK-uniprot.txt generating MurNAc-6-P |
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Download this section (compressed HTML)Q: Does KT2440 AnmK have measurable activity on substrates other than 1,6-anhydro-MurNAc?
Experiment: Purify AnmK and compare kinetics for anhMurNAc and related amino sugars, coupled to LC-MS confirmation of MurNAc-6-phosphate.
Type: biochemical activity assay
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