identifier: traitmech:000057 label: monotrichous definition: A flagellar arrangement with a single flagellum, typically located at one pole of the cell. definition_source: DOI:10.1093/femsre/fuv034 trait_category: MORPHOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - traitmech:000056 evidence: - reference: DOI:10.1093/femsre/fuv034 notes: Schuhmacher et al. describe single-flagellum (monotrichous, polar) flagellation as one regular flagellation pattern. - reference: DOI:10.3390/biom9070279 notes: Flagellum review supports a single helical flagellar filament as a locomotory organelle. canonical_examples: - taxon_id: NCBITaxon:666 taxon_label: Vibrio cholerae note: "single polar flagellum" reference: PMID:19717600 - taxon_id: NCBITaxon:155892 taxon_label: Caulobacter vibrioides note: "single polar flagellum (swarmer)" reference: PMID:31010900 causal_graphs: - graph_id: monotrichous_single_polar_flagellum title: Monotrichous flagellation — single polar flagellum description: Evidence-backed causal sketch linking a single polar bacterial flagellum to monotrichous flagellation. nodes: - node_id: monotrichous_trait label: monotrichous node_type: TRAIT grounding: traitmech:000057 description: Single flagellum, typically polar. - node_id: bacterial_flagellum label: bacterial-type flagellum node_type: CELLULAR_LOCALIZATION grounding: GO:0009288 description: Helical proteinaceous locomotory organelle. - node_id: polar_placement label: polar single-flagellum placement node_type: QUALITY description: Single flagellum positioned at one cell pole. - node_id: flhf_gtpase label: FlhF node_type: GENE_OR_PROTEIN description: SRP-type GTPase that targets and anchors flagellar assembly to the cell pole. grounding: UniProtKB:A0A656AC42 - node_id: flhg_atpase label: FlhG node_type: GENE_OR_PROTEIN description: MinD/ParA-family ATPase that regulates flagellum number and modulates FlhF. grounding: UniProtKB:Q2N2M1 - node_id: polar_flagellum_localization label: polar localization of flagellum node_type: BIOLOGICAL_PROCESS description: Targeting and confinement of flagellar assembly to one cell pole. - node_id: flagellum_number label: flagellum number per cell node_type: QUALITY description: The count of flagella per cell. - node_id: flig_protein label: FliG node_type: GENE_OR_PROTEIN description: C-ring switch protein that bridges the MS-ring to motor and chemotaxis components. grounding: UniProtKB:A0A016XEK1 - node_id: flif_msring label: FliF MS-ring protein node_type: GENE_OR_PROTEIN description: MS-ring protein forming the membrane-embedded base of the flagellar basal body. - node_id: flim_flin label: FliM/FliN C-ring partners node_type: GENE_OR_PROTEIN description: C-ring switch-complex proteins that interact with FliG in the cytoplasmic ring. edges: - subject: bacterial_flagellum predicate: defines object: monotrichous_trait description: A single polar flagellum defines the monotrichous arrangement. evidence: - reference: DOI:10.1093/femsre/fuv034 notes: Schuhmacher et al. describe single-flagellum (monotrichous) polar flagellation. predicate_id: METPO:2007500 - subject: monotrichous_trait predicate: associated with object: polar_placement description: The monotrichous pattern places one flagellum at one pole. evidence: - reference: DOI:10.3390/biom9070279 notes: Flagellum review supports a single helical flagellar filament as a locomotory organelle. predicate_id: biolink:associated_with - subject: flhf_gtpase predicate: promotes localization of object: polar_flagellum_localization description: FlhF promotes targeting of flagella to the cell pole; deleting flhF causes mislocalization to nonpolar sites. evidence: - reference: DOI:10.1128/jb.00110-23 notes: FlhF and FlhG control the location and number of flagella in many polar-flagellated bacteria; deleting flhF caused hypoflagellation and mislocalization of flagella to nonpolar sites. - subject: flhg_atpase predicate: regulates number of object: flagellum_number description: FlhG regulates the number of flagella per cell; its loss in single-flagellum bacteria often causes hyperflagellation. evidence: - reference: DOI:10.1128/jb.00110-23 notes: FlhF and FlhG control the location and number of flagella respectively; deleting flhG in bacteria with a single polar flagellum often results in hyperflagellation. - subject: flhf_gtpase predicate: binds object: flig_protein description: The FlhF B-domain FliG-Interaction Domain (FID) binds FliG. evidence: - reference: DOI:10.1038/s41467-024-50274-4 notes: The FlhF B-domain contains an N-terminal FliG Interaction Domain (FID); the N-terminal ~60 aa of the B-domain are necessary and sufficient for FliG binding. - subject: flig_protein predicate: recruits object: flif_msring description: FlhF-bound FliG engages the MS-ring protein FliF, recruiting a FliF-FliG complex to the pole. evidence: - reference: DOI:10.1038/s41467-024-50274-4 notes: FlhF-bound FliG then engages the MS-ring protein FliF, effectively recruiting a FliF-FliG complex to the pole. - subject: flhf_gtpase predicate: hinders interaction of object: flim_flin description: FlhF-bound FliG can still engage FliF but is prevented from interacting with C-ring partners FliM/FliN. evidence: - reference: DOI:10.1038/s41467-024-50274-4 notes: FlhF-bound FliG can still engage the cytoplasmic domain of FliF but is prevented from interacting with C-ring partners FliM/FliN. - subject: flhg_atpase predicate: stimulates GTPase activity of object: flhf_gtpase description: FlhG stimulates FlhF GTPase activity, modulating FlhF control over FliG interactions. evidence: - reference: DOI:10.1038/s41467-024-50274-4 notes: FlhG's modulation of FlhF controls FliG's interaction with FliM/FliN; FlhG stimulates FlhF GTPase activity. curation_history: - timestamp: '2026-06-03T00:00:00Z' curator: claude action: PROPOSED_FROM_RESEARCH changes: Proposed candidate MORPHOLOGY trait (monotrichous flagellation); sub-variant of flagellar arrangement. llm_assisted: true - timestamp: '2026-06-09T15:00:00Z' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added evidence-backed causal graph (single polar flagellum) with GO node grounding and METPO/biolink predicate groundings; promoted PROPOSED to REVIEWED. llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 6 evidence-backed generic edges (7 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-26T07:15:19Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 3 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:A0A656AC42×1, UniProtKB:Q2N2M1×1, UniProtKB:A0A016XEK1×1). llm_assisted: true