PA1058 encodes subunit F (ShaF/MrpF) of the Sha (Mrp/Mnh/Pha) multisubunit Na+/H+ antiporter of Pseudomonas aeruginosa PAO1. It is a small (89 residues) integral membrane protein with two predicted transmembrane helices, in the CPA3 antiporter subunit F (MrpF/PhaF) family. It is the fifth gene of the six-gene sha cluster PA1054-PA1059, in which shaA and shaB are fused. The cluster restores Na+ tolerance and Na+/H+ antiport to an E. coli strain lacking its major antiporters, and in P. aeruginosa the Sha antiporter is largely responsible for Na+ extrusion and supports virulence in mouse infection models. In Bacillus Mrp antiporters, a conserved aspartate of MrpF is needed for antiport and complex formation, and B. subtilis MrpF has in addition been linked to cholate efflux. Its homologue in archaeal membrane-bound hydrogenase is MBH subunit B.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Combined automated annotation (cell membrane, multi-pass). PA1058 has two predicted TM helices and is a subunit of an inner-membrane Na+/H+ antiporter complex. Reason: Correct location for a subunit of the Na+-extruding membrane complex. Supporting Evidence: file:PSEAE/PA1058/PA1058-uniprot.txt TRANSMEM 34..53 PMID:16030218 genes PA1054 to PA1059 encode a Na+/H+ antiporter that is largely responsible for Na+ extrusion in P. aeruginosa |
| GO:0015075 monoatomic ion transmembrane transporter activity | IEA GO_REF:0000120 | MODIFY | Summary: Automated annotation from the MrpF/PhaF family. Correct but general. Reason: True but general; GO:0015385 sodium:proton antiporter activity (a descendant, already on this gene) is the supported activity, to which this subunit contributes as part of the complex. Proposed replacements: sodium:proton antiporter activity Supporting Evidence: PMID:16030218 The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters |
| GO:0015297 antiporter activity | IEA GO_REF:0000104 | MODIFY | Summary: UniRule annotation from the MrpF/PhaF family. Correct but general. Reason: True but general; GO:0015385 sodium:proton antiporter activity (a descendant, already on this gene) is the supported activity, to which this subunit contributes as part of the complex. Proposed replacements: sodium:proton antiporter activity Supporting Evidence: PMID:16030218 The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters |
| GO:0015385 sodium:proton antiporter activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002162906, the LUCA root of PTHR34702 (MrpF family, 19 reference leaves, plus TreeGrafter propagations), sole-seeded by the PseudoCAP IMP row for this gene. PA1058 is ShaF of the Sha antiporter. The activity belongs to the hetero-oligomeric complex, so a subunit contributes to it. The node also covers MBH/MBX hydrogenase subunit B proteins (TK2081, TK1225). Reason: The core activity of the complex this protein belongs to; kept, with the qualifier corrected to contributes_to (GO_CENTRAL defect). Propagation Review Root cause: SOURCE WEAK OR INFERRED Sources checked: PANTHER:PTN002162906 · PTN002162906 SUPPORTS TRANSFER Family-root IBD; right for Mrp/Mnh/Pha subunit F as a contribution to complex activity. It reaches MBH/MBX hydrogenase subunits, where a Na+/H+ antiporter MF is doubtful. UniProtKB:Q9I4R6 · PA1058 (shaF) SOURCE WEAK OR INFERRED Sole seed; PseudoCAP IMP, but the PMID:16030218 abstract reports a disruption of PA1054 only. Supporting Evidence: PMID:16030218 The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters PMID:29218041 In category 1, MrpD-D75A, MrpD-R258A, MrpE-T113Y, and MrpF-D32A were studied, and their Na+/H+ antiport activity was found to be completely lost, with no Mrp complex detected. file:PSEAE/PA1058/PA1058-bioinformatics/RESULTS.md PTN002162906 is the root of the PTHR34702 tree (LUCA speciation node, is_family_root: True): 19 leaves in 16 organisms |
| GO:0015385 sodium:proton antiporter activity | IMP PMID:16030218 Characterization of a multigene-encoded sodium/hydrogen anti... | ACCEPT | Summary: PseudoCAP IMP, the sole seed of the PTN002162906 antiporter IBD. The paper shows antiport for the whole PA1054-PA1059 cluster, lost when PA1054 is deleted, and reports a P. aeruginosa disruption of PA1054 only. The abstract describes no PA1058 mutant, and the full text (read 2026-11-05) confirms none was made, so a mutant-phenotype code is wrong for PA1058. PA1058 is a subunit of the antiporter complex. Reason: PA1058 is part of the Na+/H+ antiporter, so the claim is kept as the core activity. It is a contribution (contributes_to), and the evidence is cluster-level, with no PA1058 mutant in the paper (full text checked). Both are flagged to PseudoCAP. Supporting Evidence: PMID:16030218 The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters PMID:20624916 Antiport activity requires hetero-oligomeric complexes of all six or seven hydrophobic Mrp proteins (MrpA-MrpG). |
| GO:0016020 membrane | IEA GO_REF:0000120 | MODIFY | Summary: Generic membrane location from the family mapping. Reason: True but general; GO:0005886 plasma membrane (already on this gene) is the supported location. Proposed replacements: plasma membrane Supporting Evidence: file:PSEAE/PA1058/PA1058-uniprot.txt TRANSMEM 34..53 |
| GO:0034220 monoatomic ion transmembrane transport | IEA GO_REF:0000002 | MODIFY | Summary: InterPro2GO from the MrpF/PhaF family. Correct but general. Reason: True but general; GO:0035725 sodium ion transmembrane transport (a descendant, already on this gene) is the supported process. Proposed replacements: sodium ion transmembrane transport Supporting Evidence: PMID:16030218 genes PA1054 to PA1059 encode a Na+/H+ antiporter that is largely responsible for Na+ extrusion in P. aeruginosa |
| GO:0035725 sodium ion transmembrane transport | IMP PMID:16030218 Characterization of a multigene-encoded sodium/hydrogen anti... | ACCEPT | Summary: PseudoCAP IMP. It seeds no IBD (PTN002162906 carries no GO:0035725 annotation). The Sha cluster is responsible for Na+ efflux, and PA1058 is one of its subunits. The IMP code looks wrong for PA1058 (no PA1058 mutant in the abstract). Reason: Process correct for this subunit of the Na+-extruding complex; MrpF Asp32 is needed for Mrp antiport. Evidence code flagged. Supporting Evidence: PMID:16030218 genes PA1054 to PA1059 encode a Na+/H+ antiporter that is largely responsible for Na+ extrusion in P. aeruginosa PMID:29754813 Mutations D32A and R33A in MrpF, equivalent to D29 and R30 of MBH subunit B, either abolished (D32A) or reduced (R33A) the H+/Na+ antiporter activity |
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Download this section (compressed HTML)Q: Should GO provide a cellular component term for the Mrp-type multisubunit Na+/H+ antiporter complex, by analogy with GO:1903103 potassium:proton antiporter complex, so that Sha/Mrp subunits can be annotated to the complex instead of each carrying the activity?
Q: Should the subunit F IBD at PTN002162906 reach MBH/MBX hydrogenase subunit B proteins (TK2081, TK1225)?
Q: Does P. aeruginosa ShaF, like B. subtilis MrpF, support cholate or other efflux independently of the other Sha subunits?
Experiment: Make an in-frame PA1058 (shaF) deletion, then test Na+ tolerance, Na+ efflux, bile-salt sensitivity and Sha complex assembly (BN-PAGE); express the cluster lacking only PA1058 in E. coli TO114 and assay Na+/H+ antiport in everted vesicles.
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