PA4218 (AmpP, also called AmpGh1) is a 10-helix inner-membrane transporter of the major facilitator superfamily in Pseudomonas aeruginosa, a distant paralog of the muropeptide permease AmpG (19% identity). It is classified in the RhtX/FptX siderophore transporter subfamily (NCBIfam TIGR02718, TC 2.A.1.57.1), and it is encoded in a two-gene operon with PA4219 (ampO). The transported substrate has not been demonstrated. ampP mutants fail to reach maximal beta-lactam-induced ampC expression, and ampP expression is AmpR -inducible; unlike ampG, ampP does not complement an E. coli ampG mutant.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular location mapping. Reason: PhoA/LacZ fusion topology shows a 10-helix inner-membrane protein. Supporting Evidence: PMID:21192796 AmpP fusions at amino acids 80, 170, 248, 308, 400 as well as full length were LacZ-positive and PhoA-negative, and fusions at amino acids 38, 120, 195, 278, and 360 were LacZ-negative and PhoA-positive, consistent with 10 TM domains (Figures 4A and 4B). |
| GO:0009276 Gram-negative-bacterium-type cell wall | IDA PMID:21192796 Pseudomonas aeruginosa Ξ²-lactamase induction requires two pe... | MODIFY | Summary: PseudoCAP row. GO:0009276 is the peptidoglycan layer; the paper's topology data place AmpP in the inner membrane. Reason: The supported location is the plasma (inner) membrane, which the gene already carries. Proposed replacements: plasma membrane Supporting Evidence: PMID:21192796 AmpP fusions at amino acids 80, 170, 248, 308, 400 as well as full length were LacZ-positive and PhoA-negative, and fusions at amino acids 38, 120, 195, 278, and 360 were LacZ-negative and PhoA-positive, consistent with 10 TM domains (Figures 4A and 4B). |
| GO:0016020 membrane | IBA GO_REF:0000033 | TOO GENERAL | Summary: IBA from PTN008542531. Reason: Entailed by the accepted GO:0005886 plasma membrane. |
| GO:0016020 membrane | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO membrane. Reason: Entailed by the accepted GO:0005886 plasma membrane. |
| GO:0022857 transmembrane transporter activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN008542531, seeded by human SLC33A1 (IDA), E. coli AmpG (IDA) and the PseudoCAP rows of PA4393 and PA4218 (expected self-appearance). Reason: PA4218 is an MFS permease of the RhtX/FptX subfamily; transporter activity is as specific as the evidence allows, since its substrate is not established. Supporting Evidence: file:PSEAE/PA4218/PA4218-uniprot.txt NCBIfam; TIGR02718; sider_RhtX_FptX; 1. |
| GO:0022857 transmembrane transporter activity | IDA PMID:21192796 Pseudomonas aeruginosa Ξ²-lactamase induction requires two pe... | ACCEPT | Summary: PseudoCAP seed row for PTN008542531. The full text reports topology fusions and beta-lactamase induction in mutants; no transport assay. Seed verdict UNVERIFIABLE: the claim is plausible (MFS, RhtX/FptX subfamily) but the paper does not show transporter activity directly. Reason: The claim is accepted on family evidence, consistent with the IBA and IEA rows; the IDA evidence code is the defect, not the term. Supporting Evidence: file:PSEAE/PA4218/PA4218-uniprot.txt NCBIfam; TIGR02718; sider_RhtX_FptX; 1. |
| GO:0022857 transmembrane transporter activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from the MFS signature. Reason: Consistent with the IBA row. |
| GO:0033252 regulation of beta-lactamase activity | IDA PMID:21192796 Pseudomonas aeruginosa Ξ²-lactamase induction requires two pe... | REMOVE | Summary: PseudoCAP row. ampP mutants fail to reach maximal beta-lactamase induction because ampC promoter induction is lost. Reason: The effect is on ampC expression; AmpP does not modulate beta-lactamase activity, and the mutant phenotype is upstream and indirect. Supporting Evidence: PMID:21192796 Benzyl-penicillin dependent induction of PampC-lacZ was lost in PAOampG or PAOampP (Figure 6). |
| GO:0046677 response to antibiotic | IDA PMID:21192796 Pseudomonas aeruginosa Ξ²-lactamase induction requires two pe... | KEEP AS NON CORE | Summary: PseudoCAP row. ampP is needed for maximal beta-lactamase induction, but the companion study found ampGh1 deletion had little effect on resistance. Reason: AmpP contributes to the beta-lactam-induced AmpC response, so the term is defensible, but it is a downstream phenotype of uncertain mechanism. Supporting Evidence: PMID:21192796 Benzyl-penicillin dependent induction of PampC-lacZ was lost in PAOampG or PAOampP (Figure 6). |
| GO:0055085 transmembrane transport | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from the MFS signature. Reason: True for an MFS permease and as specific as the evidence allows. |
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Experiment: Uptake assays with radiolabelled ferripyochelin and GlcNAc-anhMurNAc peptides in PA4218 deletion and complemented strains, together with cytoplasmic muropeptide profiling.
Type: transport assay
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