FleS (PA1098) is the sensor histidine kinase of the FleS-FleR two-component system of Pseudomonas aeruginosa, encoded in the fleSR operon upstream of the fliE flagellar gene. It is a 402-residue protein with an N-terminal PAS domain and a C-terminal HisKA/HATPase kinase core with the conserved phosphoacceptor histidine (His191). Its cognate response regulator FleR is a sigma-54 enhancer-binding protein; FleSR sits in the middle tier of the FleQ-led flagellar transcription hierarchy and is required for flagellar synthesis, motility and adhesion to mucin.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000155 phosphorelay sensor kinase activity | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA from PTN009166588 (seeds S. pombe Mak3, PprA, E. coli AtoS, M. tuberculosis PdtaS). Reason: The IBD rests on four seeds with direct kinase evidence (PprA IDA PMID:12499175, AtoS IDA, PdtaS IDA, Mak3 EXP). FleS sits inside the clade and keeps the catalytic residues; no divergence argued. Supporting Evidence: file:PSEAE/fleS/fleS-uniprot.txt Phosphohistidine; by autocatalysis |
| GO:0000155 phosphorelay sensor kinase activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO from the HisKA dimerisation/phosphoacceptor domain. Reason: FleS has the complete HisKA/HATPase kinase core with the conserved His191; the IBA (PTN009166588) and the cognate sigma-54 activator FleR make phosphorelay sensor kinase activity the expected function. No direct kinase assay on FleS is cached. Supporting Evidence: file:PSEAE/fleS/fleS-uniprot.txt Phosphohistidine; by autocatalysis PMID:7591148 FleS has a predicted molecular mass of 43.87 kDa and shows strong homology to histidine kinases which in other two-component systems have been shown to be sensor proteins |
| GO:0000160 phosphorelay signal transduction system | IDA PMID:7591148 Cloning and phenotypic characterization of fleS and fleR, ne... | ACCEPT | Summary: PseudoCAP IDA (IBD seed for GO:0007165 at PTN009166588), citing the paper that cloned fleS and fleR. The abstract presents FleS by sequence homology and all listed experiments are on a fleR mutant. Reason: The process is right for FleS: it is the histidine kinase of the FleS-FleR pair, and FleR is required for flagellin synthesis and motility. The claim is accepted on that synthesis. The evidence code is doubtful: the abstract (full text not obtainable, scanned PMC record) characterises FleS only by homology and lists a fleR insertion, its complementation, a flagellin Western blot and EM of the fleR mutant as the evidence. None of these is a direct assay on FleS, so IDA looks wrong; filed as a CHECK. Supporting Evidence: PMID:7591148 FleS has a predicted molecular mass of 43.87 kDa and shows strong homology to histidine kinases which in other two-component systems have been shown to be sensor proteins PMID:7591148 A nonpiliated mutant of P. aeruginosa PAK containing a gentamicin cassette in fleR is nonmotile and nonadhesive PMID:7591148 The fleSR system is believed to control both flagellar synthesis and adhesion to mucin |
| GO:0004673 protein histidine kinase activity | IEA GO_REF:0000003 | TOO GENERAL | Summary: EC 2.7.13.3 mapping. Reason: Entailed by the accepted GO:0000155. |
| GO:0004673 protein histidine kinase activity | ISS GO_REF:0000024 | TOO GENERAL | Summary: UniProt ISS from E. coli AtoS (Q06067). Reason: True, but entailed by GO:0000155 phosphorelay sensor kinase activity, accepted here. |
| GO:0007165 signal transduction | IBA GO_REF:0000033 | TOO GENERAL | Summary: PAINT IBA from PTN009166588; FleS is one of seven seeds (via its GO:0000160 row). Reason: The IBD stands without FleS: E. coli AtoS and ZraS (IDA), M. tuberculosis PdtaS (IDA) and S. pombe Mak3 carry experimental signalling annotations, and the node term suits a histidine-kinase clade. For FleS the more specific GO:0000160 is accepted and entails it. |
| GO:0007165 signal transduction | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO, signal transduction. Reason: Entailed by GO:0000160, accepted here (same call as on parS, KinB and PprA). |
| GO:0016772 transferase activity, transferring phosphorus-containing groups | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO, transferase activity transferring phosphorus-containing groups. Reason: Entailed by the accepted GO:0000155. |
Loading supporting content…
Download this section (compressed HTML)Q: What signal does the FleS PAS domain sense, and does FleS also act as a phospho-FleR phosphatase?
Experiment: Autophosphorylation and phosphotransfer assays with purified FleS and FleR (and an H191A mutant) to establish the kinase activity directly.
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)