flagellar arrangement

Deep research

Generated by just research-trait; source: research/traits/morphology/flagellar_arrangement-deep-research-falcon.md

# Curation report: bacterial flagellar arrangement

## Executive summary

**Target:** `traitmech:000056` — **flagellar arrangement**; category **MORPHOLOGY**; term kind **CLASS**; mapping **REVIEWED**; supplied parent `METPO:1000704`.

The trait should represent the **cell-level combination of flagellar number and spatial distribution**—for example monotrichous, lophotrichous, amphitrichous, and peritrichous flagellation. It should not be equated with flagellum presence, flagellar assembly, swimming motility, motor rotation, chemotaxis, or gene expression. Those are separate structures, processes, or assay outcomes that may lie upstream or downstream of arrangement.

The best-supported causal backbone for a polar-flagellation graph is:

**HubP/FimV and FipA → FlhF recruitment/activation → FliG–FliF recruitment and polar MS-ring initiation → polar flagellar placement**, with **FlhG-mediated FlhF inactivation/C-ring progression and transcriptional feedback → restriction of flagellar number**. The 2024 literature materially refines this model: FlhF is now supported as a molecular tether and assembly checkpoint, while FipA is a newly described membrane-associated licensing factor. These mechanisms are strongest in polarly flagellated Proteobacteria and must not be generalized uncritically to peritrichous species. (arroyoperez2024aconservedcellpole pages 14-15, dornes2024polarconfinementof pages 1-2)

| Proposed causal edge | Evidence class | Primary taxon | Confidence / curation status | DOI |
|---|---|---|---|---|
| HubP/FimV directly interacts with FlhF | Direct protein-protein interaction; structural/biochemical plus localization genetics | *Shewanella putrefaciens* CN-32 | High; curate as taxon-supported polar landmark interaction, not universal across all polar flagellates (dornes2024polarconfinementof pages 1-2, dornes2024polarconfinementof pages 2-4, dornes2024polarconfinementof pages 4-6) | 10.1038/s41467-024-50274-4 |
| FipA directly interacts with FlhF | Direct interaction by co-IP/MS and BACTH; conserved mutational support | *Vibrio parahaemolyticus*; also supported in *Pseudomonas putida* and *Shewanella putrefaciens* | High; curate as strong 2024 node-edge for FlhF-dependent polar synthesis pathway (arroyoperez2024aconservedcellpole pages 2-3, arroyoperez2024aconservedcellpole pages 14-15, arroyoperez2024aconservedcellpole pages 12-14, arroyoperez2024aconservedcellpole pages 8-11) | 10.7554/eLife.93004.3 |
| FlhF directly binds FliG | Direct interaction; structural and biochemical mapping of FlhF FID/B-domain to FliG | *Shewanella putrefaciens* CN-32 | High; curate as core mechanistic recruitment edge for polar assembly (dornes2024polarconfinementof pages 1-2, dornes2024polarconfinementof pages 2-4, dornes2024polarconfinementof pages 6-7) | 10.1038/s41467-024-50274-4 |
| FliG promotes/captures FliF MS-ring assembly | Biochemical assembly and localization evidence | *Vibrio* spp.; *Shewanella putrefaciens* | High but taxon-scoped; curate as assembly-promoting edge upstream of arrangement phenotype (dornes2024polarconfinementof pages 2-4, dornes2024polarconfinementof pages 6-7) | 10.1038/s41467-024-50274-4; 10.1128/JB.00236-20 |
| FlhF-bound FliG is prevented from interacting with FliM/FliN | Direct interaction antagonism/gating from biochemical interaction assays | *Shewanella putrefaciens* CN-32 | High; curate as mechanistic checkpoint edge with explicit taxon note (dornes2024polarconfinementof pages 1-2, dornes2024polarconfinementof pages 2-4, dornes2024polarconfinementof pages 6-7) | 10.1038/s41467-024-50274-4 |
| FlhG stimulates FlhF GTP hydrolysis | Biochemical/regulatory interaction supported by review synthesis and current model | Multiple polar-flagellated bacteria | Moderate-high; curate as conserved regulatory edge, but usually supported across taxa rather than a single universal assay system here (schuhmacher2015howbacteriamaintain pages 8-9, dornes2024polarconfinementof pages 7-8, dornes2024polarconfinementof pages 6-7) | 10.1093/femsre/fuv034; 10.1038/s41467-024-50274-4 |
| FlhF promotes polar flagellar placement | Mutant phenotypes, localization microscopy, rescue/inference from assembly mutants | *Helicobacter pylori*; also Vibrio/*Pseudomonas*/*Shewanella* | High; curate as trait-proximal positive edge to polar placement with species-specific quantitative manifestations (gibson2023controlofthe pages 11-13, gibson2023controlofthe pages 1-2, arroyoperez2024aconservedcellpole pages 14-15) | 10.1128/JB.00110-23; 10.7554/eLife.93004.3 |
| FlhG restricts flagellar number | Mutant phenotype genetics and review synthesis | *Helicobacter pylori*; Vibrio/*Pseudomonas*/*Shewanella* | High; curate as trait-proximal negative edge to flagellar number, with taxon-specific output distributions (gibson2023controlofthe pages 1-2, arroyoperez2024aconservedcellpole pages 1-2, gibson2023controlofthe pages 11-13) | 10.1128/JB.00110-23; 10.7554/eLife.93004.3 |
| FipA promotes FlhF polar localization and thereby polar flagellar synthesis | Localization genetics plus loss-of-function phenotype | *Vibrio parahaemolyticus*; *Pseudomonas putida*; *Shewanella putrefaciens* | High; curate as strong 2024 licensing/localization edge, noting some species retain polar positioning despite reduced number (arroyoperez2024aconservedcellpole pages 11-12, arroyoperez2024aconservedcellpole pages 14-15, arroyoperez2024aconservedcellpole pages 12-14, arroyoperez2024aconservedcellpole pages 8-11) | 10.7554/eLife.93004.3 |
| HubP/FimV contributes to proper polar flagellar placement/number via FlhF/FlhG pathway | Localization genetics and comparative phenotypes | *Vibrio parahaemolyticus*; *Shewanella putrefaciens* | Moderate; curate only with explicit species-variation warning because phenotypic strength differs across taxa (dornes2024polarconfinementof pages 7-8, arroyoperez2024aconservedcellpole pages 14-15) | 10.1038/s41467-024-50274-4; 10.7554/eLife.93004.3 |


*Table: This table prioritizes the strongest causal edges currently supported for curating traitmech:000056. It highlights which interactions are direct and high-confidence versus those that are taxon-dependent and should be curated with explicit scope notes.*

## 1. Trait scope and boundaries

### Included phenotype

A valid observation describes both or either component of the arrangement state:

- **Number:** zero, one, several, or many flagella per cell.
- **Position:** one pole, both poles, a polar tuft, lateral sites, or distribution around the cell surface.
- **Composite named pattern:** monotrichous, lophotrichous, amphitrichous, peritrichous, or a taxon-specific mixed pattern.
- **Population distribution:** where relevant, the distribution of numbers or positions across cells, rather than only the mean.

This scope is consistent with the current mechanistic literature, which uses “flagellation pattern” for species-specific flagellar location and abundance and treats FlhF and FlhG as principal spatial and numerical regulators. (gibson2023controlofthe pages 1-2, dornes2024polarconfinementof pages 1-2)

### Boundary cases

1. **Flagellum presence/absence:** “Aflagellate” is an extreme arrangement outcome, but a generic ability to synthesize a flagellum is not itself the arrangement trait.
2. **Assembly:** MS-ring, C-ring, hook, filament, and type III export assembly are upstream processes. Include them only where evidence connects them causally to number or position.
3. **Motility:** Soft-agar spread and swimming speed are indirect functional readouts. A motility defect does not establish altered arrangement without microscopy or flagellar enumeration.
4. **Chemotaxis and rotational switching:** These influence movement rather than flagellar placement or count.
5. **Cell-cycle timing:** Uni-to-bipolar localization transitions can be causal intermediates, but cell-cycle stage should be represented as experimental context unless directly manipulated.
6. **Dual flagellar systems:** Polar and lateral systems in the same organism require system-specific nodes. In *S. putrefaciens*, FlhF selectively recognizes polar FliG rather than its lateral paralog. (dornes2024polarconfinementof pages 2-4)
7. **Pilus placement and other polar organelles:** HubP/FimV can organize several polar systems; only the branch demonstrably connected to flagellar arrangement belongs in this graph. (arroyoperez2024aconservedcellpole pages 1-2)

## 2. Candidate nodes grouped by type

### Trait and phenotype nodes

- **flagellar arrangement** — `traitmech:000056`
- **flagellar number** — label-only candidate
- **polar flagellar placement** — label-only candidate
- **nonpolar/lateral mislocalization** — label-only candidate
- **monotrichous, lophotrichous, amphitrichous, peritrichous flagellation** — retain as label-only subphenotypes until exact ontology mappings are verified

Showing the first 60 of 267 lines of findings; the linked file also carries the run's front matter and the prompt it was given — read the full report.