PfeS (PA2687) is the sensor histidine kinase of the PfeS-PfeR two-component system of Pseudomonas aeruginosa, which induces the ferric enterobactin outer membrane receptor PfeA when the xenosiderophore enterobactin is present. It is an inner-membrane protein with two transmembrane helices flanking a periplasmic sensor domain (crystal structure 3KYZ), a cytoplasmic HAMP linker, a HisKA dimerization/phosphoacceptor domain with the conserved autophosphorylation histidine (His244) and an HATPase catalytic domain. By domain architecture it autophosphorylates and transfers the phosphoryl group to the response regulator PfeR, which binds the pfeA promoter and activates its transcription. PfeS has no receiver or histidine-phosphotransfer (HPt) domain, so it is a classical, not a hybrid, sensor kinase.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000155 phosphorelay sensor kinase activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002463889 seeded by E. coli BaeS and M. tuberculosis PrrB. Reason: PfeS has a transmembrane sensor architecture with HisKA (conserved His244) and HATPase domains; core function, by family. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt Phosphohistidine; by autocatalysis file:PSEAE/pfeS/pfeS-uniprot.txt PF00512; HisKA |
| GO:0000155 phosphorelay sensor kinase activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro HisKA mapping; agrees with the IBA. Reason: As for the IBA row. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt PF00512; HisKA |
| GO:0000160 phosphorelay signal transduction system | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002463889 seeded by E. coli RcsC, M. tuberculosis PrrB and this gene's PseudoCAP IDA row (self-seed). Reason: True by domain architecture and partner genetics; the IBD stands on RcsC and PrrB without this seed. Supporting Evidence: PMID:8808923 PfeR (Regulator) and PfeS (Sensor), members of the superfamily of so-called two-component regulatory protein pairs, are required for the enterobactin-inducible production of the ferric enterobactin receptor (PfeA) in Pseudomonas aeruginosa. file:PSEAE/pfeS/pfeS-uniprot.txt PF00512; HisKA |
| GO:0000160 phosphorelay signal transduction system | IDA PMID:8808923 PfeR, an enterobactin-responsive activator of ferric enterob... | ACCEPT | Summary: PseudoCAP IDA seed of PTN002463889. The cached abstract reports PfeR experiments (knockout, bandshift, fusions) and states that PfeR and PfeS are required for enterobactin-inducible pfeA expression; no PfeS assay is described. Reason: The claim is true of PfeS (domain architecture, partner genetics) and is accepted with the IBA and IEA rows. As a seed it is UNVERIFIABLE: full text could not be read, so whether an IDA-type experiment on PfeS stands behind the row is unknown; the requirement for PfeS may come from genetics (IMP) here or from earlier pfeRS work. The evidence-code question is recorded as a SUSPECTED source defect. Supporting Evidence: PMID:8808923 PfeR (Regulator) and PfeS (Sensor), members of the superfamily of so-called two-component regulatory protein pairs, are required for the enterobactin-inducible production of the ferric enterobactin receptor (PfeA) in Pseudomonas aeruginosa. |
| GO:0000160 phosphorelay signal transduction system | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro mapping; agrees with the IBA. Reason: As for the IBA row. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt PF00512; HisKA |
| GO:0004673 protein histidine kinase activity | IEA GO_REF:0000003 | TOO GENERAL | Summary: EC 2.7.13.3 mapping to protein histidine kinase activity. Reason: Entailed by GO:0000155 phosphorelay sensor kinase activity, accepted here. |
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002463889 seeded by RcsC and BaeS. Reason: Two predicted TM helices flanking a periplasmic sensor domain place PfeS in the inner membrane. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt Cell inner membrane {ECO:0000305}; Multi-pass file:PSEAE/pfeS/pfeS-uniprot.txt Periplasmic |
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular-location mapping (cell inner membrane). Reason: As for the IBA row. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt Cell inner membrane {ECO:0000305}; Multi-pass |
| GO:0007165 signal transduction | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro mapping to signal transduction. Reason: Entailed by GO:0000160 phosphorelay signal transduction system, accepted here. |
| GO:0009927 histidine phosphotransfer kinase activity | IBA GO_REF:0000033 | REMOVE | Summary: IBA for histidine phosphotransfer kinase activity from PTN002463889, seeded only by Arabidopsis AT2G17820 (AHK1). Reason: GO:0009927 is the activity of an HPt domain that shuttles phosphate between a hybrid kinase and a response regulator. PfeS is a classical sensor kinase with HAMP, HisKA and HATPase domains and no HPt or receiver domain; it phosphorylates PfeR directly. The term does not suit this bacterial sensor-kinase clade. Propagation Review Root cause: PROPAGATION BAD Failure modes: FUNCTIONAL DIVERGENCE Sources checked: PANTHER:PTN002463889 · PTN002463889 SOURCE WEAK OR INFERRED Broad sensor histidine kinase node (RcsC, BaeS, PrrB, PfeS, plant AHK1); 200 leaves in 59 taxa. An HPt-type activity seeded by one plant hybrid kinase is transferred to classical bacterial kinases that lack an HPt domain. AGI_LocusCode:AT2G17820 · Arabidopsis AHK1/HK1 SUPPORTS SOURCE BUT NOT TARGET Hybrid histidine kinase; its phosphorelay architecture does not apply to PfeS. Supporting Evidence: file:PSEAE/pfeS/pfeS-uniprot.txt PF00512; HisKA |
| GO:0016020 membrane | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro HAMP mapping to membrane. Reason: Entailed by GO:0005886 plasma membrane, accepted here. |
| GO:0016772 transferase activity, transferring phosphorus-containing groups | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro mapping to phosphotransferase activity. Reason: Entailed by GO:0000155 phosphorelay sensor kinase activity, accepted here. |
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Experiment: Purify the PfeS cytoplasmic domain and test autophosphorylation and phosphotransfer to PfeR in vitro; measure enterobactin binding to the periplasmic domain (3KYZ construct) by ITC.
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