mraY encodes phospho-N-acetylmuramoyl-pentapeptide-transferase (translocase I; EC 2.7.8.13), a polytopic integral inner-membrane enzyme that catalyzes the first committed, lipid-linked step of peptidoglycan biosynthesis. It transfers the phospho-MurNAc-pentapeptide moiety from the soluble precursor UDP-MurNAc-pentapeptide onto the membrane lipid carrier undecaprenyl phosphate, forming lipid I and releasing UMP. The reaction is Mg2+-dependent and initiates the membrane-associated lipid cycle that supplies precursors for cell wall assembly. MraY belongs to the glycosyltransferase 4 family, MraY subfamily, and is broadly conserved across bacteria.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: MraY is a multi-pass integral protein of the bacterial inner (plasma) membrane, where it acts on the membrane lipid carrier undecaprenyl phosphate. Reason: UniProt places MraY in the cell inner membrane as a multi-pass membrane protein, with ten predicted transmembrane helices, consistent with this localization. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane file:PSEPK/mraY/mraY-uniprot.txt Multi-pass membrane protein |
| GO:0008963 phospho-N-acetylmuramoyl-pentapeptide-transferase activity | IEA GO_REF:0000120 | MARK AS OVER ANNOTATED | Summary: Correct MraY activity, but less specific than the existing meso-diaminopimelate-substrate term. Reason: GO:0051992 already captures the meso-diaminopimelate-containing physiological substrate recorded for KT2440, so retaining this parent would add no information. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt RecName: Full=Phospho-N-acetylmuramoyl-pentapeptide-transferase file:PSEPK/mraY/mraY-uniprot.txt transfers peptidoglycan precursor phospho-MurNAc-pentapeptide from UDP-MurNAc- pentapeptide onto the lipid carrier undecaprenyl phosphate file:PSEPK/mraY/mraY-uniprot.txt PANTHER; PTHR22926; PHOSPHO-N-ACETYLMURAMOYL-PENTAPEPTIDE-TRANSFERASE |
| GO:0009252 peptidoglycan biosynthetic process | IEA GO_REF:0000120 | ACCEPT | Summary: MraY catalyzes the first committed lipid-linked step of peptidoglycan biosynthesis, so this is a core biological process for the gene. Reason: UniProt assigns MraY to the cell wall biogenesis / peptidoglycan biosynthesis pathway, and it initiates the lipid cycle of peptidoglycan synthesis. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. file:PSEPK/mraY/mraY-uniprot.txt Catalyzes the initial step of the lipid cycle reactions in the biosynthesis of the cell wall peptidoglycan |
| GO:0016020 membrane | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Correct but broad; the specific plasma (inner) membrane localization is the informative term and is separately annotated. Reason: GO:0016020 membrane is a broad parent of GO:0005886 plasma membrane, which is already annotated and more precisely describes the inner-membrane localization of MraY. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane |
| GO:0016780 phosphotransferase activity, for other substituted phosphate groups | IEA GO_REF:0000120 | MARK AS OVER ANNOTATED | Summary: This is a broad parent of the specific phospho-N-acetylmuramoyl-pentapeptide-transferase activity already annotated for MraY. Reason: GO:0051992 is the existing substrate-specific child term that precisely describes the KT2440 MraY reaction. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt RecName: Full=Phospho-N-acetylmuramoyl-pentapeptide-transferase |
| GO:0044038 cell wall macromolecule biosynthetic process | IEA GO_REF:0000118 | MARK AS OVER ANNOTATED | Summary: Correct but broad; the specific peptidoglycan biosynthetic process term captures MraY's role more precisely. Reason: GO:0009252 is already present as the direct pathway term, making this broad cell-wall biosynthesis parent redundant. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. |
| GO:0051992 UDP-N-acetylmuramoyl-L-alanyl-D-glutamyl-meso-2,6-diaminopimelyl-D-alanyl-D-alanine:undecaprenyl-phosphate transferase activity | IEA GO_REF:0000116 | ACCEPT | Summary: This Rhea-mapped term describes the same catalytic reaction (RHEA:28386) at the substrate level and is an accurate, precise molecular function for MraY. Reason: The term corresponds exactly to the UniProt catalytic activity (RHEA:28386, EC 2.7.8.13) using meso-diaminopimelate-containing precursor, the physiological substrate in Gram-negative Pseudomonas. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt Xref=Rhea:RHEA:28386 file:PSEPK/mraY/mraY-uniprot.txt meso- 2,6-diaminopimeloyl-D-alanyl-D-alanine + di-trans,octa-cis- undecaprenyl phosphate |
| GO:0071555 cell wall organization | IEA GO_REF:0000118 | MARK AS OVER ANNOTATED | Summary: MraY contributes to building the peptidoglycan cell wall, so this broader cell wall organization process is correct but generic given that the specific peptidoglycan biosynthetic process (GO:0009252) is also annotated and captures the role precisely. Reason: GO:0009252 is already present as the direct pathway term, making this broad cell-wall organization annotation redundant. Supporting Evidence: file:PSEPK/mraY/mraY-uniprot.txt Cell wall biogenesis/degradation file:PSEPK/mraY/mraY-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. |
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Download this section (compressed HTML)Q: Is P. putida KT2440 MraY essential for viability, and how does its activity integrate with the de novo and recycling routes that supply UDP-MurNAc-pentapeptide?
Suggested experts: Bacterial cell-wall biosynthesis experts
Q: Does Pseudomonas MraY display the same nucleoside-antibiotic (e.g. muraymycin, tunicamycin) inhibition profile observed for other bacterial MraY enzymes?
Suggested experts: Antibacterial target / translocase inhibitor experts
Experiment: Heterologously express and purify P. putida MraY in membrane/detergent and assay lipid I formation from UDP-MurNAc-pentapeptide and undecaprenyl phosphate, confirming EC 2.7.8.13 activity and Mg2+ dependence.
Type: in vitro membrane transferase (lipid I formation) assay
Experiment: Test essentiality and effect on cell shape/division via conditional depletion or attempted deletion of mraY (PP_1334) in KT2440, monitoring peptidoglycan precursor pools and morphology.
Type: conditional gene depletion and phenotypic / morphological analysis
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