{"id":"b3f844df-731d-5db8-8314-3892ba51f4ec","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-tubulin-recognition","predicate":"recognizes","statement":"TTL recognized the curved tubulin dimer and its alpha-tubulin tail, discriminating between tubulin subunits and modification states.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7ecb2727-83b1-527d-9551-ebc2edffd889","mechanism_event_label":"The enzyme needs the correct protein shape and tail, not just free amino acid.","subject":{"id":"fc12a174-0b8a-5ff0-a6ca-d62a9af11118","slug":"chicken-ttl","display_name":"Chicken tubulin tyrosine ligase / Ttl","entity_type_key":"protein"},"object":{"id":"392a3d40-4aaa-5ca4-a11d-4f23f1a77b1c","slug":"mammalian-curved-tubulin-dimer","display_name":"Curved mammalian alpha/beta-tubulin dimer","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7ecb2727-83b1-527d-9551-ebc2edffd889","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-tubulin-recognition-event","event_type":"observed_relationship","label":"The enzyme needs the correct protein shape and tail, not just free amino acid.","description":"TTL recognized the curved tubulin dimer and its alpha-tubulin tail, discriminating between tubulin subunits and modification states.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"fc12a174-0b8a-5ff0-a6ca-d62a9af11118","slug":"chicken-ttl","display_name":"Chicken tubulin tyrosine ligase / Ttl","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"392a3d40-4aaa-5ca4-a11d-4f23f1a77b1c","slug":"mammalian-curved-tubulin-dimer","display_name":"Curved mammalian alpha/beta-tubulin dimer","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2538baea-6c5b-5fc9-b4ab-385085073ba3","slug":"mammalian-brain-tubulin-terminal-tyrosine","display_name":"Bovine/porcine brain alpha-tubulin terminal tyrosine","entity_type_key":"cellular_process"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full text; Results","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Chicken TTL structural reconstitution; tubulin-binding and activity comparisons.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Tubulin modification state controls access; the finding does not show dietary tyrosine is rate limiting.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The enzyme needs the correct protein shape and tail, not just free amino acid.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structural basis of tubulin tyrosination by tubulin tyrosine ligase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23358242/ · DOI 10.1083/jcb.201211017","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"8be712bb-ad01-5747-a61d-456f98f9cd3b","evidence_kind":"source_excerpt","locator":"Lines 324-330","start_line":324,"end_line":330,"excerpt":"## l-tyrosine-tubulin-recognition\nThe enzyme needs the correct protein shape and tail, not just free amino acid.\nTTL recognized the curved tubulin dimer and its alpha-tubulin tail, discriminating between tubulin subunits and modification states.\nModel: Chicken TTL structural reconstitution; tubulin-binding and activity comparisons.\nLimitations: Tubulin modification state controls access; the finding does not show dietary tyrosine is rate limiting.\nEvidence access: Primary full text; Results\nStructural basis of tubulin tyrosination by tubulin tyrosine ligase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23358242/ · DOI 10.1083/jcb.201211017","model_system":"Chicken TTL structural reconstitution; tubulin-binding and activity comparisons.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"12917df2-c6e0-5b61-850f-dbff6d4b4d30","stable_key":"import-63ce713e-6aea-59f6-9896-ca30e010b2ce","title":"L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"7777f4440a8bfb14a04ff73e73392ccc45d8ee89f7853ecbcc0027d6f563b8a0","revision_id":"e1206111-3a75-5809-b8e9-231ff809ff1e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}