{"id":"984f89d1-46dc-5d43-ba89-1bba34597d92","stable_key":"97957230-601f-5dec-8524-0812be8fadbf:l-threonine-galnt2-f104s","predicate":"when_f104s_loses","statement":"GALNT2 F104S disrupted the UDP-GalNAc-dependent active conformation and peptide-substrate binding.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"fbb5b296-8a91-550c-9684-c51a3c1adb2e","mechanism_event_label":"A sugar donor and amino-acid-containing protein are insufficient if the modifying enzyme cannot bind correctly.","subject":{"id":"2c25648b-ab89-5f6e-9fd5-c623abc65d15","slug":"galnt2","display_name":"Human polypeptide GalNAc transferase 2 / GALNT2","entity_type_key":"protein"},"object":{"id":"53cca0da-d3d4-5f56-9f7a-219a0a73a46c","slug":"human-galnt2-peptide-binding","display_name":"Human GALNT2 peptide-substrate binding","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"fbb5b296-8a91-550c-9684-c51a3c1adb2e","stable_key":"97957230-601f-5dec-8524-0812be8fadbf:l-threonine-galnt2-f104s-event","event_type":"observed_relationship","label":"A sugar donor and amino-acid-containing protein are insufficient if the modifying enzyme cannot bind correctly.","description":"GALNT2 F104S disrupted the UDP-GalNAc-dependent active conformation and peptide-substrate binding.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"2c25648b-ab89-5f6e-9fd5-c623abc65d15","slug":"galnt2","display_name":"Human polypeptide GalNAc transferase 2 / GALNT2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"53cca0da-d3d4-5f56-9f7a-219a0a73a46c","slug":"human-galnt2-peptide-binding","display_name":"Human GALNT2 peptide-substrate binding","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"fcef4dc2-a7b6-5812-bc33-c8af3d83f4d0","slug":"l-threonine","display_name":"L-Threonine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"42c9cea9-1d97-5a7c-b4f0-cbefc9fc23ab","slug":"udp-n-acetylgalactosamine","display_name":"UDP-N-acetylgalactosamine / UDP-GalNAc","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"0b8a4e76-bf31-527d-83a3-f37f6e945e10","slug":"protein-bound-threonine","display_name":"Protein-bound L-threonine residue","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human mutant crystal structure, NMR and molecular-dynamics analysis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No correction of this defect by threonine supplementation was demonstrated.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Threonine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-threonine","display_name":"L-Threonine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A sugar donor and amino-acid-containing protein are insufficient if the modifying enzyme cannot bind correctly.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structural Analysis of a GalNAc-T2 Mutant Reveals an Induced-Fit Catalytic Mechanism for GalNAc-Ts. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29601100/ · DOI 10.1002/chem.201800701","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"76d980b3-bbad-5c23-814b-a8f720291e2c","evidence_kind":"source_excerpt","locator":"Lines 194-200","start_line":194,"end_line":200,"excerpt":"## l-threonine-galnt2-f104s\nA sugar donor and amino-acid-containing protein are insufficient if the modifying enzyme cannot bind correctly.\nGALNT2 F104S disrupted the UDP-GalNAc-dependent active conformation and peptide-substrate binding.\nModel: Human mutant crystal structure, NMR and molecular-dynamics analysis.\nLimitations: No correction of this defect by threonine supplementation was demonstrated.\nEvidence access: Primary abstract\nStructural Analysis of a GalNAc-T2 Mutant Reveals an Induced-Fit Catalytic Mechanism for GalNAc-Ts. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29601100/ · DOI 10.1002/chem.201800701","model_system":"Human mutant crystal structure, NMR and molecular-dynamics analysis.","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":"35396730-235a-537e-8a05-c6ef2960c509","stable_key":"import-97957230-601f-5dec-8524-0812be8fadbf","title":"L-Threonine: translation, intestinal barrier, 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":"3365aed939d9f567bd098449c7d67c7c00fb6c9ba163dcf34dc7cf6081f324fb","revision_id":"10a7b648-8dd7-5d4e-b618-c560a6e2d3c7","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}