PA5504 is the five-helix permease (MetI-like, binding protein-dependent transport system permease) subunit of an ATP-binding cassette amino acid importer in the inner membrane of Pseudomonas aeruginosa PAO1. It is encoded next to the ATPase MetN2 (PA5503) and the lipoprotein PA5502, and is a close homologue of Escherichia coli MetI, the permease of the MetNIQ L- and D-methionine importer, so it most likely forms the translocation channel of a methionine uptake system. A transposon mutant grew less well on L-histidine as carbon source in a high-throughput screen, but substrate specificity has not been tested by uptake assays.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000765163, seeded by E. coli MetI (IDA) and two other permeases. Reason: Polytopic ABC permease of the Gram-negative inner membrane. Supporting Evidence: file:PSEAE/PA5504/PA5504-uniprot.txt TRANSMEM 196..215 |
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: SubCell mapping. Reason: Same claim as the IBA row. |
| GO:0016020 membrane | IEA GO_REF:0000120 | TOO GENERAL | Summary: Combined IEA membrane. Reason: Entailed by GO:0005886 plasma membrane, accepted above. |
| GO:0043190 ATP-binding cassette (ABC) transporter complex | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule ABC transporter complex. Reason: PA5504 is the permease subunit of an ABC importer with MetN2. The methionine-specific complex term (GO:1990197) is not adopted because the substrate is untested in P. aeruginosa. |
| GO:0048473 D-methionine transmembrane transport | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000765164, seeded by E. coli MetI (IMP PMID:12218041; EXP ABC-type D-methionine transporter activity). PA5504 is a MetI-family permease (NCBIfam metI) beside a MetN ATPase. Reason: Best-supported substrate assignment: the clade-level inference agrees with the NCBIfam family and the genomic neighbour MetN2. No P. aeruginosa uptake data exist, so this rests on phylogeny. Supporting Evidence: file:PSEAE/PA5504/PA5504-uniprot.txt NCBIfam; NF008049; metI; 1. |
| GO:0055085 transmembrane transport | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO from the MetI-like domain. Reason: Entailed by GO:0048473 D-methionine transmembrane transport, accepted above. |
| GO:1903810 L-histidine import across plasma membrane | IMP PMID:18833300 High-throughput phenotypic characterization of Pseudomonas a... | UNDECIDED | Summary: PseudoCAP seed row for PTN000765163 (node term GO:0006865 amino acid transport). The only evidence is a partial growth defect of a transposon mutant on L-histidine; there is no uptake assay and histidine did not induce the gene. Seed verdict OVER-SPECIFIC. Reason: The growth defect supports a role in amino acid utilization, and so the node-level term, but does not establish histidine as the transported substrate. It conflicts with the MetI-family assignment and could be indirect (for example a polar or fitness effect in a Biolog well). Until histidine uptake is measured the substrate-specific claim can be neither accepted nor removed. Supporting Evidence: PMID:18833300 A PA5504 knockout affected growth on L-histidine as a carbon source (Table 2), however its expression was not induced by this compound. |
Loading supporting content…
Download this section (compressed HTML)Q: Does the PA5502-PA5504 MetNIQ-type system import methionine, histidine or both, and is the histidine growth defect of the PA5504 mutant due to transport?
Experiment: Measure uptake of radiolabelled L-methionine, D-methionine and L-histidine in a clean PA5504 deletion and its complemented strain, and test growth on D-methionine as sole sulfur or carbon source.
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)