MurG is the peripheral inner-membrane glycosyltransferase that forms lipid II in Pseudomonas putida KT2440. On the cytoplasmic face of the membrane it transfers N-acetylglucosamine from UDP-GlcNAc to lipid I, producing the disaccharide-pentapeptide precursor exported for peptidoglycan polymerization.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Correct location at the cytoplasmic face of the bacterial inner membrane. Reason: UniProt identifies MurG as a peripheral inner-membrane protein. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane |
| GO:0005975 carbohydrate metabolic process | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Broad process annotation that obscures lipid II synthesis. Reason: MurG acts specifically in peptidoglycan biosynthesis. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. |
| GO:0009252 peptidoglycan biosynthetic process | IEA GO_REF:0000120 | ACCEPT | Summary: Correct core biological process. Reason: UniProt places Q88N76 in peptidoglycan biosynthesis. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. |
| GO:0016757 glycosyltransferase activity | IEA GO_REF:0000118 | KEEP AS NON CORE | Summary: True catalytic parent of MurG's GlcNAc transfer to lipid I. Reason: GO:0016757 is a direct is_a ancestor of GO:0050511 undecaprenyldiphospho-muramoylpentapeptide beta-N-acetylglucosaminyltransferase activity, which MurG already carries, and UniProt describes the transfer of a GlcNAc moiety from UDP-GlcNAc to lipid I. The parent term is therefore simply true; per the audit rules an ancestor whose specific descendant is already annotated is retained as non-core rather than marked over-annotated. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt FUNCTION: Cell wall formation. Catalyzes the transfer of a GlcNAc |
| GO:0016758 hexosyltransferase activity | IEA GO_REF:0000120 | MARK AS OVER ANNOTATED | Summary: Broad catalytic parent of the exact MurG activity. Reason: The target reaction is known at substrate level, so generic hexosyltransferase activity is redundant. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt FUNCTION: Cell wall formation. Catalyzes the transfer of a GlcNAc |
| GO:0050511 undecaprenyldiphospho-muramoylpentapeptide beta-N-acetylglucosaminyltransferase activity | IEA GO_REF:0000120 | MARK AS OVER ANNOTATED | Summary: Correct MurG activity at a slightly broader substrate-description level. Reason: GO:0051991 captures the exact DAP-containing lipid I substrate recorded for KT2440 and is preferred for the gene-level core function. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt muramoyl-L-alanyl-D-glutamyl-meso-2,6-diaminopimeloyl-D-alanyl-D- |
| GO:0051991 UDP-N-acetyl-D-glucosamine:N-acetylmuramoyl-L-alanyl-D-glutamyl-meso-2,6-diaminopimelyl-D-alanyl-D-alanine-diphosphoundecaprenol 4-beta-N-acetylglucosaminlytransferase activity | IEA GO_REF:0000116 | ACCEPT | Summary: Correct substrate-specific core molecular function. Reason: The Rhea-mapped term matches the recorded transfer of GlcNAc from UDP-GlcNAc to the DAP-containing lipid I precursor. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt Reaction=di-trans,octa-cis-undecaprenyl diphospho-N-acetyl-alpha-D- file:PSEPK/murG/murG-deep-research-openscientist.md MurG is a UDP-GlcNAc:lipid I Ξ²-1,4-GlcNAc transferase producing lipid II (EC 2.4.1.227). |
| GO:1901137 carbohydrate derivative biosynthetic process | IEA GO_REF:0000117 | MARK AS OVER ANNOTATED | Summary: Broad process annotation that obscures the defined cell-wall pathway. Reason: Peptidoglycan biosynthesis is the direct and informative process for MurG. Supporting Evidence: file:PSEPK/murG/murG-uniprot.txt PATHWAY: Cell wall biogenesis; peptidoglycan biosynthesis. |
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Download this section (compressed HTML)Q: How is KT2440 MurG recruited or retained at active peptidoglycan synthesis sites?
Experiment: Track functional fluorescent MurG fusions during growth and perturbations, and test interactions with MraY, MurJ, and divisome proteins.
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Download this section (compressed HTML)Q88N76/PP_1337 forms lipid II by transferring GlcNAc to lipid I on the
cytoplasmic face of the inner membrane
[UniProtKB:Q88N76, "FUNCTION: Cell wall formation. Catalyzes the transfer of a
GlcNAc"; "SUBCELLULAR LOCATION: Cell inner membrane"].
The DAP-specific Rhea term is used for the KT2440 gene-level core function.
Generic glycosyltransferase terms and broad carbohydrate-process terms are
modified to the exact reaction or peptidoglycan biosynthesis. The reusable
module retains the shorter MurG activity term so it is not restricted to one
stem-peptide chemistry.
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