identifier: METPO:1000693
label: spirochete shaped
definition: A cell shape in which an organism has an elongated, tightly coiled helical
  morphology with periplasmic flagella (endoflagella) located between the cell wall
  and outer membrane.
definition_source: DOI:10.1073/pnas.200221797
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000666
synonyms:
- synonym_text: spirochete
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
created_by: Jed Dongjin Kim-Ozaeta
evidence:
- reference: DOI:10.1073/pnas.200221797
  snippet: periplasmic flagella ... confer in part its flat-wave morphology
  notes: Supports spirochete morphology as a cell-cylinder and periplasmic-flagella
    interaction.
canonical_examples:
- taxon_id: NCBITaxon:160
  taxon_label: Treponema pallidum
  note: "Syphilis spirochete; textbook flat-wave spirochete morphology with periplasmic flagella. Leptospira/Borrelia are alternative spirochete exemplars."
  reference: DOI:10.1128/jb.01031-09
causal_graphs:
- graph_id: spirochete_shaped_periplasmic_flagella
  title: Spirochete-shape periplasmic flagella mechanism
  description: Evidence-backed causal sketch linking spirochete morphology to the
    cell cylinder, periplasmic flagella, FlaB filament protein, and flat-wave or helical
    cell-body deformation.
  nodes:
  - node_id: spirochete_shaped_trait
    label: spirochete shaped
    node_type: TRAIT
    grounding: METPO:1000693
    description: Elongated helical or flat-wave spirochete morphology.
  - node_id: cell_cylinder
    label: cell cylinder
    node_type: CELLULAR_LOCALIZATION
    description: Rod-like cell body within the outer membrane sheath.
  - node_id: periplasmic_flagella
    label: periplasmic flagella
    node_type: ORGANELLE
    description: Internal flagella located in the periplasmic space.
  - node_id: flaB
    label: FlaB
    node_type: GENE_OR_PROTEIN
    description: Major periplasmic flagellar filament protein in Borrelia.
    grounding: UniProtKB:A8WEP6
  - node_id: flat_wave_morphology
    label: flat-wave morphology
    node_type: BIOLOGICAL_PROCESS
    description: Wave-like deformation of the spirochete cell body.
  - node_id: cell_body_deformation
    label: cell body deformation
    node_type: BIOLOGICAL_PROCESS
    description: Distortion and pushing of the spirochete cell body by periplasmic
      flagellar motor action.
  - node_id: flhE
    label: FlhE
    node_type: GENE_OR_PROTEIN
    description: Periplasmic Sec-translocated protein preventing ectopic flagellar
      filament assembly in the periplasm.
    grounding: UniProtKB:A0A192C731
  - node_id: ectopic_periplasmic_filament_assembly
    label: ectopic periplasmic filament assembly
    node_type: BIOLOGICAL_PROCESS
    description: Aberrant assembly of flagellar filaments in the periplasm.
  - node_id: divisome_elongasome_localization
    label: divisome and elongasome localization
    node_type: BIOLOGICAL_PROCESS
    description: Localization of cell-division and elongation complexes required for
      peptidoglycan synthesis.
  - node_id: flgV
    label: FlgV
    node_type: GENE_OR_PROTEIN
    description: Broadly conserved basal-body protein that modulates periplasmic flagellar
      filament assembly.
  - node_id: cell_morphology_division
    label: cell division and morphology
    node_type: BIOLOGICAL_PROCESS
    description: Cell-division and whole-cell shape processes in spirochetes.
  edges:
  - subject: flaB
    predicate: builds
    object: periplasmic_flagella
    description: FlaB is required for periplasmic flagellar filaments.
    evidence:
    - reference: DOI:10.1073/pnas.200221797
      snippet: gene encoding the major periplasmic flagellar filament protein FlaB
      notes: Targeted mutagenesis of flaB removed periplasmic flagella in Borrelia
        burgdorferi.
    predicate_id: biolink:produces
  - subject: periplasmic_flagella
    predicate: interact with
    object: cell_cylinder
    description: Periplasmic flagella interact with the cell cylinder to deform the
      spirochete body.
    evidence:
    - reference: DOI:10.1073/pnas.200221797
      snippet: complex interaction between the cell cylinder and the internal periplasmic
        flagella
      notes: Supports a physical interaction between flagella and cell cylinder.
    predicate_id: biolink:interacts_with
  - subject: periplasmic_flagella
    predicate: confers
    object: flat_wave_morphology
    description: Periplasmic flagella provide a skeletal function that confers flat-wave
      morphology.
    evidence:
    - reference: DOI:10.1073/pnas.200221797
      snippet: have a skeletal function
      notes: Supports periplasmic flagella as morphology-shaping structures.
  - subject: flat_wave_morphology
    predicate: produces
    object: spirochete_shaped_trait
    description: Flat-wave or helical deformation produces spirochete morphology.
    evidence:
    - reference: DOI:10.1073/pnas.200221797
      snippet: cell morphology is either a helix, a flat wave, or an irregularly shaped
        helix
      notes: Supports spirochete-shape classes and their dependence on internal flagella-cell-body
        geometry.
    predicate_id: METPO:2000202
  - subject: periplasmic_flagella
    predicate: distort and push
    object: cell_body_deformation
    description: Periplasmic flagella enclosed in the periplasm distort and push the
      cell body by flagellar motor action.
    evidence:
    - reference: DOI:10.1093/pnasnexus/pgad349
      notes: spirochete flagella are enclosed in the periplasmic space and the filaments
        distort and push the cell body by action of the flagellar motors
  - subject: cell_body_deformation
    predicate: produces
    object: spirochete_shaped_trait
    description: Flagella-driven cell body deformation produces the helical or flat-wave
      spirochete morphology.
    evidence:
    - reference: DOI:10.1093/pnasnexus/pgad349
      notes: Endoflagella-driven distortion of the cell body underlies spirochete
        shape.
    predicate_id: METPO:2000202
  - subject: flhE
    predicate: prevents
    object: ectopic_periplasmic_filament_assembly
    description: FlhE prevents ectopic assembly of flagellar filaments in the periplasm.
    evidence:
    - reference: DOI:10.1038/s41467-024-50278-0
      notes: FlhE is a periplasmic, Sec-translocated protein that prevents ectopic
        assembly of flagellar filaments in the periplasm.
    predicate_id: RO:0002212
  - subject: ectopic_periplasmic_filament_assembly
    predicate: mislocalizes
    object: divisome_elongasome_localization
    description: Ectopic periplasmic filament assembly mislocalizes divisome and elongasome
      complexes required for peptidoglycan synthesis.
    evidence:
    - reference: DOI:10.1038/s41467-024-50278-0
      notes: periplasmic filament assembly causally mis-localizes divisome and elongasome
        complexes required for peptidoglycan synthesis
  - subject: divisome_elongasome_localization
    predicate: alters
    object: spirochete_shaped_trait
    description: Mislocalized divisome/elongasome alters cell curvature and rod morphology,
      coupling periplasmic filaments to envelope shape.
    evidence:
    - reference: DOI:10.1038/s41467-024-50278-0
      notes: producing altered cell curvature/loss of rod morphology and infrequent
        cell lysis
  - subject: flgV
    predicate: modulates
    object: periplasmic_flagella
    description: FlgV localizes to the flagellar basal body and modulates periplasmic
      flagellar filament assembly.
    evidence:
    - reference: DOI:10.1038/s41467-024-54806-w
      notes: FlgV localizes to the flagellar basal body and altering FlgV levels profoundly
        impacts filament assembly
    predicate_id: RO:0002211
  - subject: flgV
    predicate: perturbs
    object: cell_morphology_division
    description: Reduced or aberrant FlgV levels perturb cell division and cell morphology
      in spirochetes.
    evidence:
    - reference: DOI:10.1038/s41467-024-54806-w
      notes: ΔflgV mutants exhibit defects in cell division and motility, including
        conjoined spirochetes; overproduction leads to cell elongation
curation_history:
- timestamp: '2026-05-05T01:35:46.899870+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-11T18:00:00-07:00'
  curator: codex
  action: CURATED_WITH_LITERATURE
  changes: Replaced broad definition source with DOI-backed spirochete morphology
    evidence and added causal graph for FlaB, periplasmic flagella, cell cylinder,
    and flat-wave morphology.
  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
    (METPO:2000202×1).
  llm_assisted: true
- timestamp: '2026-05-24T05:05:15Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A8WEP6×1).
  llm_assisted: true
- timestamp: '2026-06-13T21:03:26Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:produces×1, biolink:interacts_with×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 7 evidence-backed generic edges (6 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:14Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×1, RO:0002212×1, RO:0002211×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:20Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A192C731×1).
  llm_assisted: true