murU encodes N-acetylmuramate alpha-1-phosphate uridylyltransferase, an enzyme in the P. putida KT2440 peptidoglycan recycling shortcut. It converts MurNAc-alpha-1-phosphate and UTP to UDP-MurNAc, supplying a cell-wall precursor through a recycling route that bypasses de novo UDP-MurNAc biosynthesis and contributes to intrinsic fosfomycin resistance.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0016779 nucleotidyltransferase activity | IEA GO_REF:0000117 | MODIFY | Summary: This parent nucleotidyltransferase term is directionally correct but less informative than the retained uridylyltransferase activity. Reason: GO:0070569 is the specific child term for the MurU reaction. Falcon deep research confirms MurU is specifically a uridylyltransferase that generates UDP-MurNAc, so the generic nucleotidyltransferase parent is less informative. Proposed replacements: uridylyltransferase activity Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt RecName: Full=N-acetylmuramate alpha-1-phosphate uridylyltransferase file:PSEPK/murU/murU-deep-research-falcon.md In the retrieved literature corpus, βMurUβ is consistently used for the **MurNAc (N-acetylmuramic acid) salvage/recycling uridylyltransferase** that generates UDP-MurNAc downstream of an anomeric MurNAc kinase (AmgK). |
| GO:0009254 peptidoglycan turnover | IEA GO_REF:0000041 | ACCEPT | Summary: MurU acts in the peptidoglycan recycling shortcut that generates UDP-MurNAc from recycled MurNAc. Reason: This pathway role is directly supported by the mutant and biochemical evidence. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan recycling. file:PSEPK/murU/murU-uniprot.txt peptidoglycan recycling as part of a cell wall recycling pathway file:PSEPK/murU/murU-deep-research-falcon.md The MurU salvage route is biologically important because it provides an **alternate route to UDP-MurNAc** that can **bypass dependence on the de novo MurA/MurB steps** under conditions where de novo synthesis is impaired (e.g., MurA inhibition by fosfomycin), a point emphasized in the labeling-and-rescue framework. |
| GO:0000287 magnesium ion binding | IDA PMID:25767118 Crystal Structure of the N-Acetylmuramic Acid Ξ±-1-Phosphate ... | KEEP AS NON CORE | Summary: Magnesium is a supported cofactor for the uridylyltransferase reaction, but ion binding is ancillary to the catalytic function. Reason: Retain as non-core cofactor binding. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt Name=Mg(2+); Xref=ChEBI:CHEBI:18420; |
| GO:0002134 UTP binding | IDA PMID:25767118 Crystal Structure of the N-Acetylmuramic Acid Ξ±-1-Phosphate ... | KEEP AS NON CORE | Summary: UTP binding is expected and experimentally supported for this uridylyltransferase, but the biological function is the transferase reaction. Reason: Retain as substrate/co-substrate binding, not as a core function summary. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt Cannot accept other nucleotide triphosphates (ATP, |
| GO:0009254 peptidoglycan turnover | IMP PMID:23831760 A cell wall recycling shortcut that bypasses peptidoglycan d... | ACCEPT | Summary: MurU acts in the peptidoglycan recycling shortcut that generates UDP-MurNAc from recycled MurNAc. Reason: This pathway role is directly supported by the mutant and biochemical evidence. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan recycling. file:PSEPK/murU/murU-uniprot.txt peptidoglycan recycling as part of a cell wall recycling pathway file:PSEPK/murU/murU-deep-research-falcon.md The MurU salvage route is biologically important because it provides an **alternate route to UDP-MurNAc** that can **bypass dependence on the de novo MurA/MurB steps** under conditions where de novo synthesis is impaired (e.g., MurA inhibition by fosfomycin), a point emphasized in the labeling-and-rescue framework. |
| GO:0070569 uridylyltransferase activity | IDA PMID:23831760 A cell wall recycling shortcut that bypasses peptidoglycan d... | ACCEPT | Summary: MurU directly catalyzes uridylyl transfer from UTP to MurNAc-alpha-1-phosphate, so this is the core molecular function. Reason: The term captures the experimentally supported EC 2.7.7.99 activity. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt EC=2.7.7.99 file:PSEPK/murU/murU-uniprot.txt Reaction=N-acetyl-alpha-D-muramate 1-phosphate + UDP + H(+) = UDP-N- |
| GO:0070569 uridylyltransferase activity | IDA PMID:25767118 Crystal Structure of the N-Acetylmuramic Acid Ξ±-1-Phosphate ... | ACCEPT | Summary: MurU directly catalyzes uridylyl transfer from UTP to MurNAc-alpha-1-phosphate, so this is the core molecular function. Reason: The term captures the experimentally supported EC 2.7.7.99 activity. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt EC=2.7.7.99 file:PSEPK/murU/murU-uniprot.txt Reaction=N-acetyl-alpha-D-muramate 1-phosphate + UDP + H(+) = UDP-N- |
| GO:0097172 N-acetylmuramic acid metabolic process | IMP PMID:23831760 A cell wall recycling shortcut that bypasses peptidoglycan d... | ACCEPT | Summary: The enzyme directly metabolizes an N-acetylmuramic acid derivative in the recycling route. Reason: MurU catalyzes conversion of MurNAc-alpha-1-phosphate to UDP-MurNAc. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt Catalyzes the formation of UDP-N-acetylmuramate (UDP-MurNAc), file:PSEPK/murU/murU-uniprot.txt a crucial precursor of the bacterial peptidoglycan cell wall, from UTP |
| GO:0097367 carbohydrate derivative binding | IDA PMID:25767118 Crystal Structure of the N-Acetylmuramic Acid Ξ±-1-Phosphate ... | KEEP AS NON CORE | Summary: MurU binds carbohydrate-derived MurNAc-alpha-1-phosphate as substrate; the binding term is valid but less informative than the reaction term. Reason: Retain as non-core substrate binding. Supporting Evidence: file:PSEPK/murU/murU-uniprot.txt MurNAc-alpha-1P (PubMed:23831760, PubMed:25767118). |
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Download this section (compressed HTML)Q: Under which environmental conditions does MurU-dependent MurNAc salvage materially contribute to peptidoglycan precursor supply or fosfomycin tolerance in KT2440?
Suggested experts: Bacterial cell-wall recycling experts
Experiment: Compare wild type, murU deletion, and complemented strains for growth on exogenous MurNAc, UDP-MurNAc pool sizes, and fosfomycin sensitivity with and without MurNAc supplementation.
Type: cell-wall precursor metabolomics and antibiotic sensitivity assay
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