identifier: METPO:1000705
label: axially filamented
definition: A motility where the flagellum filament of an organism is located in the
  periplasm and does not extend past the cell envelope.
definition_source: DOI:10.3390/biom10040550
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000702
synonyms:
- synonym_text: axial filament
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
created_by: Luke Wang
evidence:
- reference: DOI:10.3390/biom10040550
  snippet: flagella are hidden within the periplasmic space
  notes: Supports axial/periplasmic flagella as the defining motility structure.
canonical_examples:
- taxon_id: NCBITaxon:173
  taxon_label: Leptospira interrogans
  note: "Spirochete with axial filaments (periplasmic endoflagella within the periplasm driving corkscrew motility)."
  reference: PMID:32157997
causal_graphs:
- graph_id: axially_filamented_periplasmic_flagella
  title: Axial filament periplasmic flagella mechanism
  description: Evidence-backed causal sketch linking axial filament motility to periplasmic
    flagella, basal motors, cell-envelope localization, torque, and corkscrew-like
    cell movement.
  nodes:
  - node_id: axially_filamented_trait
    label: axially filamented
    node_type: TRAIT
    grounding: METPO:1000705
    description: Motility with flagellar filaments located in the periplasm.
  - node_id: periplasmic_flagella
    label: periplasmic flagella
    node_type: CELLULAR_LOCALIZATION
    description: Flagella located between the cell wall and outer membrane.
  - node_id: flagellar_basal_motor
    label: flagellar basal motor
    node_type: GENE_OR_PROTEIN
    description: Motor embedded in the cytoplasmic membrane and peptidoglycan layer.
  - node_id: periplasmic_space
    label: periplasmic space
    node_type: CELLULAR_LOCALIZATION
    description: Space between inner and outer membranes containing spirochete flagella.
    grounding: GO:0042597
  - node_id: torque_generation
    label: torque generation
    node_type: BIOLOGICAL_PROCESS
    description: Motor-generated force that deforms or rotates the cell body.
  - node_id: corkscrew_motility
    label: corkscrew motility
    node_type: BIOLOGICAL_PROCESS
    description: Helical or undulating movement produced by periplasmic flagella.
  - node_id: flbb_ring
    label: FlbB periplasmic ring
    node_type: GENE_OR_PROTEIN
    description: Spirochete-specific FlbB protein ring that forms around the flagellar
      rotor and scaffolds the collar.
  - node_id: flagellar_rotor
    label: flagellar rotor
    node_type: GENE_OR_PROTEIN
    description: Rotating core of the flagellar motor (MS/C ring) around which the
      FlbB ring forms.
  - node_id: stator_complex
    label: stator complex
    node_type: GENE_OR_PROTEIN
    description: Ion-powered torque-generating stator units recruited around the rotor
      for flagellar rotation.
  - node_id: wavy_cell_morphology
    label: wavy / flat-wave cell morphology
    node_type: QUALITY
    description: Helical/flat-wave cell body shape established by periplasmic flagella
      acting like a cytoskeleton.
  edges:
  - subject: periplasmic_flagella
    predicate: defines
    object: axially_filamented_trait
    description: Axial filamented motility is defined by flagella located inside the
      periplasmic space.
    evidence:
    - reference: DOI:10.3390/biom10040550
      snippet: flagella are hidden within the periplasmic space
      notes: Supports periplasmic flagella as the defining structure.
    predicate_id: METPO:2007500
  - subject: periplasmic_flagella
    predicate: localized in
    object: periplasmic_space
    description: Spirochete flagella reside inside the cell envelope rather than extending
      externally.
    evidence:
    - reference: DOI:10.1016/j.semcdb.2015.10.015
      snippet: enclose their flagella in the periplasm
      notes: Supports periplasmic localization of spirochete flagella.
    predicate_id: biolink:located_in
  - subject: flagellar_basal_motor
    predicate: rotates
    object: periplasmic_flagella
    description: Basal motors drive periplasmic flagellar rotation.
    evidence:
    - reference: DOI:10.3390/biom10040550
      snippet: connects with a basal motor
      notes: Supports basal motor linkage to periplasmic flagella.
  - subject: torque_generation
    predicate: depends on
    object: flagellar_basal_motor
    description: Spirochete-specific motor structures generate torque needed for motility.
    evidence:
    - reference: DOI:10.1128/mBio.02494-21
      snippet: generation of the high torque necessary
      notes: Supports torque generation by spirochete flagellar motor structures.
    predicate_id: RO:0002502
  - subject: periplasmic_flagella
    predicate: enables
    object: corkscrew_motility
    description: Periplasmic flagella drive cell-body undulation or corkscrew-like
      movement.
    evidence:
    - reference: DOI:10.1016/j.semcdb.2015.10.015
      snippet: long, helical appendages known as flagella to move
      notes: Supports motility by periplasmic flagella in spirochetes.
    predicate_id: RO:0002327
  - subject: corkscrew_motility
    predicate: realizes
    object: axially_filamented_trait
    description: Corkscrew or undulating movement is the observed locomotion phenotype
      of axial filament systems.
    evidence:
    - reference: DOI:10.3390/biom10040550
      snippet: mechanics of spirochete motility
      notes: Supports cell-body mechanics as the phenotype-level expression of periplasmic
        flagella.
  - subject: flbb_ring
    predicate: forms ring around
    object: flagellar_rotor
    description: FlbB forms a novel periplasmic ring around the flagellar rotor, a
      structural scaffold for the spirochete motor.
    evidence:
    - reference: DOI:10.1371/journal.ppat.1012812
      notes: '"FlbB forms a novel periplasmic ring around the rotor"; broadly applicable
        to spirochetes with FlbB homologs.'
  - subject: flbb_ring
    predicate: recruits
    object: stator_complex
    description: The FlbB-based collar scaffold supports recruitment of torque-generating
      stator complexes around the rotor.
    evidence:
    - reference: DOI:10.1371/journal.ppat.1012812
      notes: '"acts as a scaffold supporting collar assembly and subsequent recruitment
        of stator complexes"'
  - subject: stator_complex
    predicate: generates
    object: torque_generation
    description: Ion-powered stator complexes generate the torque that drives periplasmic
      flagellar rotation.
    evidence:
    - reference: DOI:10.1371/journal.ppat.1012812
      notes: '"bridges the rotor and 16 torque-generating stator complexes in each
        flagellar motor"; stators are the torque-generating units.'
    predicate_id: biolink:produces
  - subject: periplasmic_flagella
    predicate: contributes to
    object: wavy_cell_morphology
    description: Periplasmic flagella establish the wavy/flat-wave cell morphology,
      acting like a cytoskeleton.
    evidence:
    - reference: DOI:10.3390/biom10040550
      notes: '"Another important role of the PF is to establish a wavy morphology,
        similar to a cytoskeleton"'
    predicate_id: RO:0002326
curation_history:
- timestamp: '2026-05-05T01:35:46.907078+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-11T00:00:00-07:00'
  curator: codex
  action: CURATED_WITH_LITERATURE
  changes: Reviewed axially filamented trait and added DOI-backed causal graph for
    periplasmic flagella, basal motors, torque generation, and spirochete corkscrew
    motility.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:31Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002327×1).
  llm_assisted: true
- timestamp: '2026-05-23T08:21:49Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:located_in×1, RO:0002502×1).
  llm_assisted: true
- timestamp: '2026-05-24T04:38:00Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (GO:0042597×1).
  llm_assisted: true
- timestamp: '2026-05-24T07:37:40Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2007500×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 4 evidence-backed generic edges (4 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:12Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:produces×1, RO:0002326×1).
  llm_assisted: true