{"id":"c2bfd7f5-9899-507e-a8a3-015882c4c5a5","stable_key":"a9828b14-fbd7-57bf-9e01-0d52d1b42a1f:citrulline-oat-reaction","predicate":"transaminates_ornithine_to","statement":"OAT transfers the ornithine delta-amino group to 2-oxoglutarate, yielding glutamate and glutamate semialdehyde, which cyclizes to P5C.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"6cb57c42-7d33-5f06-a92b-006b1785f03f","mechanism_event_label":"This is an ornithine-processing reaction; its direction depends on the biological setting.","subject":{"id":"ddcb770b-d815-5f25-b055-f1f15174140e","slug":"oat","display_name":"Human ornithine aminotransferase / OAT","entity_type_key":"protein"},"object":{"id":"33e6c1dc-af9c-5ec6-8e23-6c15bff974f5","slug":"glutamate-5-semialdehyde","display_name":"L-Glutamate-5-semialdehyde","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"6cb57c42-7d33-5f06-a92b-006b1785f03f","stable_key":"a9828b14-fbd7-57bf-9e01-0d52d1b42a1f:citrulline-oat-reaction-event","event_type":"biochemical_relationship","label":"This is an ornithine-processing reaction; its direction depends on the biological setting.","description":"OAT transfers the ornithine delta-amino group to 2-oxoglutarate, yielding glutamate and glutamate semialdehyde, which cyclizes to P5C.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"c715e48e-42db-5fac-b4a4-c1285a68d085","slug":"ornithine","display_name":"L-Ornithine","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"7da684a4-2641-5bc6-93ae-8c6aa384e487","slug":"glutamate","display_name":"L-Glutamate","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"cbf8b66e-3d66-53f0-9c21-bc9c014131e7","slug":"pyrroline-5-carboxylate","display_name":"Delta-1-pyrroline-5-carboxylate / P5C","entity_type_key":"small_molecule"},"role":"cyclized_product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"cofactor","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"ddcb770b-d815-5f25-b055-f1f15174140e","slug":"oat","display_name":"Human ornithine aminotransferase / OAT","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"33e6c1dc-af9c-5ec6-8e23-6c15bff974f5","slug":"glutamate-5-semialdehyde","display_name":"L-Glutamate-5-semialdehyde","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/citrulline-research/9514741.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"cca17abd35f0211a043dd3cc8883369e230209206ff62b62242197f90201cea0\", \"start_char\": 0, \"end_char\": 2979, \"text_sha256\": \"cca17abd35f0211a043dd3cc8883369e230209206ff62b62242197f90201cea0\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant enzyme crystal structure","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"PLP-bound enzyme structure","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The described reaction direction is ornithine transamination; this structure alone does not quantify reverse flux in human intestine.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Citrulline research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"citrulline","display_name":"L-Citrulline","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human OAT","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"This is an ornithine-processing reaction; its direction depends on the biological setting.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[citrulline-p9514741] Crystal structure of human recombinant ornithine aminotransferase. (1998). https://pubmed.ncbi.nlm.nih.gov/9514741/ DOI: 10.1006/jmbi.1997.1583","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Mitochondrial ornithine transamination","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"4ba52a3e-87fe-561d-a452-9a10307a448f","evidence_kind":"source_excerpt","locator":"Lines 346-357","start_line":346,"end_line":357,"excerpt":"### citrulline-oat-reaction\nOAT transfers the ornithine delta-amino group to 2-oxoglutarate, yielding glutamate and glutamate semialdehyde, which cyclizes to P5C.\nCondition category: normal\nnutrient_topic: Citrulline research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: This is an ornithine-processing reaction; its direction depends on the biological setting.\norganism: Human OAT\ntissue_or_cell_type: Mitochondrial ornithine transamination\nexperimental_model: Recombinant enzyme crystal structure\nlimitations: The described reaction direction is ornithine transamination; this structure alone does not quantify reverse flux in human intestine.\nexposure: PLP-bound enzyme structure\nevidence_span: {\"source_cache\": \"artifacts/citrulline-research/9514741.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"cca17abd35f0211a043dd3cc8883369e230209206ff62b62242197f90201cea0\", \"start_char\": 0, \"end_char\": 2979, \"text_sha256\": \"cca17abd35f0211a043dd3cc8883369e230209206ff62b62242197f90201cea0\"}\n[citrulline-p9514741] Crystal structure of human recombinant ornithine aminotransferase. 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