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motile

METPO:1000702 · CLASS · REVIEWED

A motility in which an organism has the ability to move independently using metabolic energy.

Energy-dependent bacterial locomotion

Evidence-backed causal sketch linking motile phenotype to metabolic energy, ion motive force, flagella, pili, and directional regulation.

Energy-dependent bacterial locomotion Interactive directed graph showing evidence-backed causal relationships for motile.

Edge evidence

  • metabolic energy generates ion motive force biolink:produces

    Metabolism supports ion gradients that can power motility.

    • DOI:10.3389/fmicb.2021.659464 ion motive force powering the bacterial flagellar motor Supports energy transduction from ion gradients into motor function.
  • ion motive force powers flagellar motor METPO:2007900

    Ion motive force powers rotation of the flagellar motor.

    • DOI:10.3389/fmicb.2021.659464 The Dynamic Ion Motive Force Powering Review directly addresses ion motive force powering flagellar motors.
  • flagellar motor confers motile METPO:2007700

    Flagellar rotation enables independent bacterial movement.

    • DOI:10.3390/biom9070279 responsible for motility Supports flagella-driven motility.
  • type IV pilus confers motile METPO:2007700

    Type IV pilus extension and retraction enable surface motility.

    • DOI:10.1038/s41579-019-0195-4 enable T4P to perform Supports pilus-mediated twitching and related motility functions.
  • chemotaxis signaling directs motile RO:0002211

    Chemotaxis signaling regulates motility direction in response to environmental changes.

    • DOI:10.3390/biom9070279 migrate towards more desirable environments Supports chemotaxis regulation of motile behavior.
  • MotA-MotB stator complex acts as transmembrane H+ channel activity

    The MotA-MotB stator acts as a transmembrane H+ channel.

    • DOI:10.3390/biom14121488 it can act as a transmembrane H+ channel
  • transmembrane H+ channel activity generates flagellar motor torque biolink:produces

    H+ flux through the stator generates torque via electrostatic interaction with FliG.

    • DOI:10.3390/biom14121488 conducts H+ through the channel to generate torque by electrostatic interactions between MotA and FliG
  • flagellar motor torque acts on FliG rotor protein

    Torque is generated by electrostatic interaction between the stator and the FliG rotor.

    • DOI:10.3390/biom14121488 electrostatic interactions between MotA and FliG generate torque on the rotor
  • flagellar motor torque powers flagellar motor METPO:2007900

    Torque generation drives rotation of the flagellar motor.

    • DOI:10.3390/biom14121488 a membrane-embedded rotary motor fueled by an ion motive force across the cytoplasmic membrane
  • CheA histidine kinase phosphorylates CheY response regulator

    Phosphorylated CheA transfers phosphate to the response regulator CheY.

    • DOI:10.3390/biom14121488 Phosphorylated CheA transfers its phosphate group to a response regulator called CheY
  • CheY response regulator binds flagellar C-ring switch complex

    Phosphorylated CheY binds the C-ring switch complex to control rotation direction.

    • DOI:10.3390/biom14121488 Phosphorylated CheY (CheY-P) binds to the C-ring
  • flagellar C-ring switch complex regulates chemotaxis signaling RO:0002211

    CheY-P binding to the C-ring switches motor rotation direction, implementing chemotactic responses.

    • DOI:10.3390/biom14121488 allowing the motor to switch the direction of rotation from CCW to CW
  • PilB extension ATPase promotes type IV pilus extension RO:0002213

    PilB ATPase powers type IV pilus extension/assembly.

    • DOI:10.1128/msphere.00390-24 PilB (extension ATPase)
  • PilT retraction ATPase promotes type IV pilus retraction RO:0002213

    PilT ATPase powers type IV pilus retraction/disassembly.

    • DOI:10.1128/msphere.00390-24 PilT (retraction ATPase)
  • type IV pilus extension enables twitching motility RO:0002327

    Cycles of T4P extension and retraction power twitching surface motility.

    • DOI:10.1128/msphere.00390-24 recurrent cycles of T4P assembly (extension) and disassembly (retraction) power surface movement
  • type IV pilus retraction enables twitching motility RO:0002327

    Cycles of T4P extension and retraction power twitching surface motility.

    • DOI:10.1128/msphere.00390-24 recurrent cycles of T4P assembly (extension) and disassembly (retraction) power surface movement
  • twitching motility confers motile METPO:2007700

    Twitching motility is a form of independent surface movement.

    • DOI:10.1128/msphere.00390-24 recurrent cycles of T4P assembly and disassembly power surface movement (twitching motility)
  • SprB adhesin surface movement drives gliding motility

    Movement of the SprB adhesin along the outer membrane drives gliding motility.

    • DOI:10.1128/jb.00068-24 gliding... is driven by the surface movement of adhesins (notably SprB) along the outer membrane
  • gliding motility confers motile METPO:2007700

    Gliding motility is a non-flagellar mechanism of independent movement.

    • DOI:10.1128/jb.00068-24 gliding is a form of surface motility driven by adhesin movement

Provenance

Source
METPO (2025-11-25)
Definition source
DOI:10.1038/s41579-021-00626-4

Parent traits (1)

Children (5)

Synonyms (1)

  • yes RELATED_SYNONYM · metpo.owl

kg-microbe context

Matched 1 kg-microbe node via direct_metpo.

  • METPO:1000702 [+24.397, -70.567, +20.807, -80.811, …]

512-dim DeepWalkSkipGramEnsmallen embedding from kg-microbe (2026-04-25).

Nearest neighbors in embedding space

Top-8 cosine-similar METPO traits from the 2026-04-25 deepwalk (512-D).

Deep research

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

Unreviewed literature output — not curated TraitMech content Ontology identifiers suggested below have not been resolved against their ontologies, and some are known to be wrong. Check any CURIE against the source before using it. 
# Curation report: microbial trait **motile**

**Target trait:** `METPO:1000702`  
**Category:** MORPHOLOGY · **Term kind:** CLASS · **Mapping:** REVIEWED  
**Definition supplied:** “A motility in which an organism has the ability to move independently using metabolic energy.”  
**Parent:** `METPO:1000701`

## Executive curation recommendation

`METPO:1000702` should represent an organism-level capacity for **active, metabolically energized displacement**, not merely movement observed in an assay. Its causal graph should be modular rather than imply that every motile microbe possesses the same machinery. High-confidence modules are: (1) ion-motive-force-driven bacterial flagellar locomotion; (2) ATP-driven type IV pilus (T4P) twitching; (3) ATP-powered archaeal motility, including archaella and the newly demonstrated Aap-pilus twitching mechanism; and (4) taxon-specific active gliding systems. Chemotaxis controls direction or switching but is neither necessary nor sufficient for the parent trait.

The central graph can therefore be expressed as:

**metabolic energy → motor activity → appendage or adhesion-system dynamics → propulsive force → cellular displacement → `METPO:1000702`.**

| module | energy input | core machinery | locomotion output | strongest recent evidence | curation confidence |
|---|---|---|---|---|---|
| Core Motility Graph Modules |  |  |  |  |  |
| Bacterial flagellar motility | Proton motive force / ion motive force | Flagellar motor stators MotAB and/or MotCD, rotor, flagellum | Swimming; in some taxa also swarming/surface spreading | Direct 2024 motor evidence in *Pseudomonas aeruginosa* shows two H+-driven stator systems with additive torque contributions; foundational reviews support IMF-to-rotation coupling (wu2024torquespeedrelationshipof pages 1-2, botting2023flgvformsa pages 1-2) | High |
| Bacterial T4P twitching | ATP | Type IV pilus machine with PilB extension ATPase, PilT primary retraction ATPase, PilU accessory retraction ATPase, T4P filament | Twitching surface translocation | 2024 reviews and experiments support ATPase-powered T4P cycles and surface-dependent twitching behavior (ohara2024surfacehydrophilicitypromotes pages 1-2, geiger2024abacterialsense pages 1-3) | High |
| Archaeal Aap twitching | ATP-linked; PilT-independent | AapF-dependent adhesion pili (Aap pili); no dedicated PilT homolog established | Twitching motility on surfaces | 2024 *Sulfolobus acidocaldarius* study shows retractable Aap pili drive twitching under physiological conditions despite lack of PilT homolog (charlesorszag2024adhesionpilusretraction pages 1-2) | Medium-High |
| Active gliding | Proton motive force (taxon-specific evidence) | Myxobacterial focal-adhesion-like gliding machinery; AgmT-linked coupling to peptidoglycan | Surface gliding | 2024 evidence supports PMF-coupled myxobacterial gliding machinery, but mechanisms are not unified across gliding taxa (rosko2025cellularcoordinationunderpins pages 16-17) | Medium |
| Boundary / non-trait movement | None intrinsic, or indirect colony-level physicochemical forcing | Growth-driven sliding; passive spreading / swashing-like colony expansion | Colony expansion without dedicated locomotor nanomachine | Reviews distinguish sliding as non-active; propulsion-independent spreading should be excluded from METPO:1000702 core mechanism graph (jin2024microbesinporous pages 14-18) | High for exclusion |


*Table: This table summarizes the main mechanistic modules relevant to curating the motile trait causal graph and separates core energy-dependent locomotion from excluded boundary phenomena. It is useful as a compact blueprint for which modules are ready for TraitMech curation and which require caution.*

## 1. Trait scope and boundaries

### Included phenotype

A microbial cell is *motile* when it can use metabolic energy to generate force that displaces itself relative to its surroundings. Included modes are:

- **Flagellar swimming** in liquid or hydrated matrices.
- **Flagellar swarming** where active flagellar propulsion is demonstrated.
- **T4P-dependent twitching**, generated by cycles of pilus extension, attachment, and retraction.
- **Archaellar swimming**, in which an ATP-powered rotating archaellum propels an archaeal cell.
- **Active gliding**, but only when a metabolically powered force-generating mechanism is established for the relevant taxon.

The phenotype is a **capacity**, so a genetically motile organism can appear stationary under conditions that suppress motor expression, energy supply, hydration, or mechanical coupling. Conversely, colony expansion does not prove intrinsic motility.

### Nearby traits that must remain distinct

1. **Chemotaxis:** biased orientation or switching in response to a chemical gradient. A cell may be motile but non-chemotactic, while intact chemosensory genes do not establish propulsion.
2. **Phototaxis, aerotaxis, mechanotaxis:** directional control layers upstream of a locomotor apparatus, not synonyms for motility.
3. **Sliding:** growth-driven colony expansion caused by division and surface forces. A 2024 review explicitly distinguishes sliding as non-active and mechanically driven by cell proliferation; exclude it from the core graph. (jin2024microbesinporous pages 14-18)
4. **Passive transport:** Brownian motion, sedimentation, bulk-flow advection, host-driven transport, or movement on a fluid wave does not meet the “using metabolic energy” definition.
5. **Swashing or osmotic spreading:** fermentation can indirectly generate osmotic gradients and fluid movement, but cells are carried by a colony-scale fluid mechanism rather than a dedicated locomotor motor. This is a boundary phenotype and should not be curated as direct evidence of `METPO:1000702` without single-cell evidence.
6. **Growth halo:** a soft-agar halo combines motility, growth, chemotaxis, agar structure, hydration, and nutrient effects. It is assay evidence, not itself the mechanism.
7. **Appendage presence:** flagella or pili seen by microscopy do not establish that the appendage is functional or that cells are motile.
8. **Intracellular molecular movement:** chromosome segregation, protein trafficking, and cytoplasmic streaming are not organismal locomotion.

## 2. Candidate graph nodes

Ontology identifiers are intentionally conservative. The supplied identifier `METPO:1000702` should be retained verbatim. Labels are preferable to guessed CURIEs; species-specific proteins should receive UniProt accessions only after strain-level verification.

### A. Trait and process nodes

- `METPO:1000702` — motile.
- Active cellular locomotion — label-only umbrella process.

Showing the first 60 of 277 lines of findings; the linked file also carries the run's front matter and the prompt it was given — read the full report.

Curation history

  1. · SEEDED_FROM_METPO · seed_from_metpo

    imported from data/raw/metpo.owl (CLASS)

  2. · CURATED_WITH_ORGANISM_EXAMPLE · codex

    Added Pseudomonas aeruginosa organism example with PMID-backed evidence.

  3. · CURATED_WITH_LITERATURE · codex

    Replaced PMID definition source with DOI-backed motility review and added causal graph for energy-dependent locomotion by flagella, type IV pili, ion motive force, and chemotaxis.

  4. · GROUND_CAUSAL_PREDICATES · claude

    Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×2).

  5. · GROUND_CAUSAL_PREDICATES · claude

    Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (biolink:produces×1).

  6. · GROUND_CAUSAL_PREDICATES · claude

    Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002211×1).

  7. · GROUND_CAUSAL_NODES · claude

    Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:R6TBR9×1).

  8. · RENAME_PREDICATE_LABELS · claude

    Renamed 1 causal-edge predicate label(s) to align with existing groundings: powers → enables ×1.

  9. · GROUND_CAUSAL_PREDICATES · claude

    Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×1).

  10. · GROUND_CAUSAL_NODES · claude

    Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0006935×1).

  11. · REMOVE_REDUNDANT_SYNONYM · claude

    Removed 1 synonym(s) whose text duplicated the label (seeder redundancy; no information lost).

  12. · ENRICH_CAUSAL_GRAPH · claude

    Added 14 evidence-backed generic edges (14 new nodes) from the deep-research report.

  13. · GROUND_CAUSAL_PREDICATES · claude

    Grounded 9 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×5, RO:0002213×2, biolink:produces×1, RO:0002211×1).

  14. · GROUND_CAUSAL_NODES · claude

    Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0043107×1).

  15. · GROUND_CAUSAL_NODES · claude

    Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:G0HQV3×1, UniProtKB:A0A2X5A7X5×1).

  16. · RETRACT_DEAD_UNIPROT_GROUNDINGS · claude

    Retracted 3 UniProtKB grounding(s) whose accessions are deleted from UniProt; nodes demoted to label-only pending re-grounding (docs/GROUNDING_POLICY.md)

  17. · GROUND_CAUSAL_NODES · claude

    Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0044096×1).

  18. · MIGRATE_ENABLES_TRAIT_EDGES · claude

    Migrated 4 causal edge(s) off enables/RO:0002327 with a TRAIT object (4 to confers), issue 302. RO:0002327 has range 'biological process or activity', which a trait (a disposition) cannot satisfy, so the previous form entailed trait is-a BiologicalProcessOrActivity. The replacements are proposed in proposals/metpo_traitmech_v8 and are placeholder ids until METPO mints them.

  19. · REGROUND_CAUSAL_EDGE · claude

    Re-grounded causal edge(s) off enables/RO:0002327 onto contributes to (RO:0002326), issue 334. biolink declares enables range 'biological process or activity', which only BIOLOGICAL_PROCESS, PATHWAY and MOLECULAR_FUNCTION satisfy, so an edge pointing at a GENE_OR_PROTEIN entailed a false type. The replacements are chosen per idiom rather than swept: a gene cluster ENCODES its product, a subunit is PART OF the complex it belongs to, and an energy source or acquired repertoire CONTRIBUTES TO the machine it powers or composes. All three declare no rdfs:domain or rdfs:range, so none can reintroduce the class of defect being removed.

  20. · REGROUND_CAUSAL_EDGE · claude

    Reverted the motive-force edge from contributes to back to enables/RO:0002327, issue 334 review. biolink defines contributes to as holding where one entity contributes to the occurrence or GENERATION of the other. A motive force does not generate the motor or machinery - it powers rotation, which is what the edge description says. That is the same energy-powers-a-machine idiom this work deferred for molecular_oxygen and cytoplasmic_na, so deferring it here too is the consistent call. The edge stays baselined under issue 334 until it is modelled as an input to the machine or pointed at the rotation process, either of which is range-correct.

  21. · REGROUND_CAUSAL_EDGE · claude

    Edge ion_motive_force -> flagellar_motor in graph motile_energy_dependent_locomotion: re-grounded it from enables/RO:0002327 to powers/METPO:2007900. Issue 334. biolink declares enables range 'biological process or activity', which of CausalNodeTypeEnum only BIOLOGICAL_PROCESS, PATHWAY and MOLECULAR_FUNCTION satisfy, so this edge entailed a false type on its object. 'Ion motive force POWERS rotation of the flagellar motor.'

  22. · REGROUND_CAUSAL_EDGE · claude

    Edge motor_torque -> flagellar_motor in graph motile_energy_dependent_locomotion: re-grounded it from enables/RO:0002327 to powers/METPO:2007900. Issue 334. biolink declares enables range 'biological process or activity', which of CausalNodeTypeEnum only BIOLOGICAL_PROCESS, PATHWAY and MOLECULAR_FUNCTION satisfy, so this edge entailed a false type on its object. 'Torque generation drives rotation of the flagellar motor.'