PA3761 encodes the N-acetylglucosamine-specific enzyme IIBC of the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS) of Pseudomonas aeruginosa, an inner-membrane protein of the NagE family (TCDB 4.A.1.1.15) with an eight-helix EIIC translocation domain followed by two EIIB domains, the first carrying the phosphocysteine active site. It works with PA3760, a fused enzyme I/HPr/enzyme IIA, at the end of a glucosamine utilisation operon, to take up N-acetylglucosamine as N-acetylglucosamine 6-phosphate. Mutants in either gene fail to grow on N-acetylglucosamine as sole carbon source, and the genes are induced by N-acetylglucosamine.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from the PTS glucose-family EIICB node PTN002011274. Reason: EIIC is an integral inner-membrane domain (eight predicted TM helices); the PTS transporter acts in the cytoplasmic membrane. Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt The EIIC domain type-1 forms the PTS system translocation channel and contains the specific substrate-binding site. |
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Subcellular location mapping (cell inner membrane, multi-pass). Reason: Correct location, as for the IBA row. Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt TRANSMEM 12..30 |
| GO:0008982 protein-N(PI)-phosphohistidine-carbohydrate phosphotransferase activity | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO from the EIIB/EIIC signatures. Reason: Right in essence (PTS sugar phosphotransferase/translocator), but the substrate is known and the EIIC step uses the phosphocysteine of the fused EIIB domain (ACT_SITE 405). GO:0090586, the GlcNAc-specific phosphocysteine PTS term used for E. coli NagE, is the precise replacement. Proposed replacements: protein-phosphocysteine-N-acetylglucosamine phosphotransferase system transporter activity Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt Phosphocysteine intermediate; for EIIB activity PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). |
| GO:0009401 phosphoenolpyruvate-dependent sugar phosphotransferase system | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002011274; seeds include E. coli NagE and PtsG. Reason: EIIBC proteins are the membrane components of the PTS. Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt The EIIC domain type-1 forms the PTS system translocation channel and contains the specific substrate-binding site. |
| GO:0009401 phosphoenolpyruvate-dependent sugar phosphotransferase system | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from the EIIB/EIIC signatures. Reason: Correct, as for the IBA row. Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt PTS-II-BC-nag |
| GO:0015572 N-acetylglucosamine transmembrane transporter activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from the NagE-type EIIBC signature IPR010974. Reason: Correct substrate-specific transporter term, supported by the growth phenotype on N-acetylglucosamine and the NagE family placement. Supporting Evidence: PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). |
| GO:0015764 N-acetylglucosamine transport | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000768523 (NagE subfamily node, 14 leaf IBAs in 11 taxa), seeded by E. coli NagE (P09323, IDA PMID:4919472) and this gene (PseudoCAP IMP PMID:18833300). Reason: Core process. The IBD stands on the E. coli NagE IDA seed alone, and the PseudoCAP seed is sound. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000768523 · PTN000768523 SUPPORTS TRANSFER NagE-type GlcNAc EIIBC clade; the node term suits it. UniProtKB:P09323 · E. coli NagE SUPPORTS TRANSFER IDA seed (EcoCyc, PMID:4919472; QuickGO 2026-11-05). UniProtKB:Q9HXN4 · PA3761 (self; PseudoCAP IMP PMID:18833300) SUPPORTS TRANSFER Expected self-seed; growth defect on GlcNAc as sole carbon source (full text read), consistent with the NagE family placement. Supporting Evidence: PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). |
| GO:0015764 N-acetylglucosamine transport | IMP PMID:18833300 High-throughput phenotypic characterization of Pseudomonas a... | ACCEPT | Summary: PseudoCAP seed row. Johnson et al. 2008 (full text) screened transporter mutants with Biolog plates; the PA3761 mutant could not use N-acetylglucosamine as carbon source (and the gene was induced by it). Reason: Seed verdict SOUND. A growth defect alone could reflect catabolism, but PA3761 is the NagE-family EIIBC and the defect is specific to GlcNAc, so the transport term is the right reading. Supporting Evidence: PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). PMID:18833300 As for the fructose PTS genes, expression of the N-acetylglucosamine PTS genes was induced by their apparent transported substrate (Table 3). |
| GO:0016020 membrane | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO generic membrane. Reason: Entailed by GO:0005886 plasma membrane (is_a membrane), accepted above. |
| GO:0019866 organelle inner membrane | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO from IPR010974. The bacterial inner membrane is the plasma membrane, not the inner membrane of an organelle envelope. Reason: The intended claim (inner membrane) is right, but the GO term is an organelle term that does not apply to a bacterium; the correct term is GO:0005886 plasma membrane, which the gene already carries. Proposed replacements: plasma membrane Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt TRANSMEM 12..30 |
| GO:0051119 sugar transmembrane transporter activity | IEA GO_REF:0000104 | MODIFY | Summary: UniRule generic sugar transporter term. Reason: The substrate is known; GO:0015572 N-acetylglucosamine transmembrane transporter activity (already on this gene) is the informative term. Proposed replacements: N-acetylglucosamine transmembrane transporter activity Supporting Evidence: PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). |
| GO:0090563 protein-phosphocysteine-sugar phosphotransferase activity | IBA GO_REF:0000033 | MODIFY | Summary: IBA from the glucose-family EIICB node PTN002011274 (seeds E. coli NagE and PtsG). Reason: Correct at the node, which spans glucose and GlcNAc EIIBCs; for this NagE-subfamily member the GlcNAc-specific child GO:0090586 (the term E. coli NagE carries by IDA) is the precise term. Propagation Review Root cause: NO FAILURE CORE Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN002011274 · PTN002011274 SUPPORTS TRANSFER Glucose-family EIICB node; the generic term suits a node holding both glucose and GlcNAc transporters. The leaf-level term is GO:0090586. UniProtKB:P09323 · E. coli NagE SUPPORTS TRANSFER Carries GO:0090586 by IDA (PMID:3056518). UniProtKB:P69786 · E. coli PtsG SUPPORTS SOURCE BUT NOT TARGET Glucose-specific; supports the generic node term, not GlcNAc. Proposed replacements: protein-phosphocysteine-N-acetylglucosamine phosphotransferase system transporter activity Supporting Evidence: file:PSEAE/PA3761/PA3761-uniprot.txt Phosphocysteine intermediate; for EIIB activity PMID:18833300 Knockouts in either PA3760 or PA3761 were defective in growth on N-acetylglucosamine as a sole carbon source, based on both Biolog and growth data (Table 2). |
Loading supporting content…
Download this section (compressed HTML)Q: PA3761 carries a second EIIB-like domain (residues 491-570) that UniProt flags as lacking the conserved residues. Is it a degenerate duplicate, or does it have a structural role in the EIIBC?
Experiment: Measure [14C]N-acetylglucosamine uptake and PEP-dependent GlcNAc phosphorylation in membranes of wild type, PA3761 and PA3761 C405A mutants to confirm transport and the phosphocysteine mechanism directly.
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)