{"id":"3d28c90a-090a-522c-ad72-7bb3b9da8376","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:acat1-acetoacetyl-coa-thiolysis","predicate":"converted_to","statement":"Human mitochondrial acetoacetyl-CoA thiolase ACAT1/T2, a homotetramer, uses coenzyme A to cleave acetoacetyl-CoA into two acetyl-CoA molecules.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"45845d3d-547a-56b6-9707-20a25866e85c","mechanism_event_label":"The four-carbon intermediate is split into two acetyl-CoA molecules.","subject":{"id":"080298d2-4743-5488-aa8d-48c00985fb7b","slug":"acetoacetyl-coa","display_name":"Acetoacetyl-CoA","entity_type_key":"small_molecule"},"object":{"id":"b7ed6e4c-e560-5cee-b68f-895f21862e6f","slug":"acetyl-coa","display_name":"Acetyl-CoA","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"45845d3d-547a-56b6-9707-20a25866e85c","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:acat1-acetoacetyl-coa-thiolysis-event","event_type":"biochemical_relationship","label":"The four-carbon intermediate is split into two acetyl-CoA molecules.","description":"Human mitochondrial acetoacetyl-CoA thiolase ACAT1/T2, a homotetramer, uses coenzyme A to cleave acetoacetyl-CoA into two acetyl-CoA molecules.","status":"provisional","compartment":{"slug":"mitochondrial-matrix","display_name":"Mitochondrial matrix"},"participants":[{"entity":{"id":"0e8ff928-bcb5-5c6a-9c77-4e5456c07980","slug":"acat1-homotetramer","display_name":"Mitochondrial ACAT1 homotetramer","entity_type_key":"protein_complex"},"role":"catalyst","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4e3ca267-b01e-550b-aa8e-4db62e54102d","slug":"acat1","display_name":"Mitochondrial acetyl-CoA acetyltransferase / ACAT1","entity_type_key":"protein"},"role":"catalytic_subunit","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"080298d2-4743-5488-aa8d-48c00985fb7b","slug":"acetoacetyl-coa","display_name":"Acetoacetyl-CoA","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"4faa6456-aff8-59eb-9e3f-3326a436e401","slug":"coenzyme-a","display_name":"Coenzyme A","entity_type_key":"small_molecule"},"role":"cosubstrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"b7ed6e4c-e560-5cee-b68f-895f21862e6f","slug":"acetyl-coa","display_name":"Acetyl-CoA","entity_type_key":"small_molecule"},"role":"product","stoichiometry":2.0,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Purified recombinant human ACAT1/T2 enzyme kinetics and crystal structures","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Thiolase chemistry is reversible and shared with ketone metabolism. These experiments do not measure lysine-specific flux. ACAT1 here denotes acetyl-CoA acetyltransferase, not cholesterol acyltransferase SOAT1.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The four-carbon intermediate is split into two acetyl-CoA molecules.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[haapalainen2007] Crystallographic and kinetic studies of human mitochondrial acetoacetyl-CoA thiolase: the importance of potassium and chloride ions for its structure and function (2007). https://pubmed.ncbi.nlm.nih.gov/17371050/ DOI: 10.1021/bi6026192","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Mitochondrial matrix enzyme; recombinant protein study","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"948f22a1-e390-5e49-b412-9d5f549f6bb0","evidence_kind":"source_excerpt","locator":"Lines 377-385","start_line":377,"end_line":385,"excerpt":"### acat1-acetoacetyl-coa-thiolysis\nHuman mitochondrial acetoacetyl-CoA thiolase ACAT1/T2, a homotetramer, uses coenzyme A to cleave acetoacetyl-CoA into two acetyl-CoA molecules.\nPlain language: The four-carbon intermediate is split into two acetyl-CoA molecules.\nCondition category: normal\norganism: Homo sapiens\ntissue_or_cell_type: Mitochondrial matrix enzyme; recombinant protein study\nexperimental_model: Purified recombinant human ACAT1/T2 enzyme kinetics and crystal structures\nlimitations: Thiolase chemistry is reversible and shared with ketone metabolism. These experiments do not measure lysine-specific flux. ACAT1 here denotes acetyl-CoA acetyltransferase, not cholesterol acyltransferase SOAT1.\n[haapalainen2007] Crystallographic and kinetic studies of human mitochondrial acetoacetyl-CoA thiolase: the importance of potassium and chloride ions for its structure and function (2007). https://pubmed.ncbi.nlm.nih.gov/17371050/ DOI: 10.1021/bi6026192","model_system":"Purified recombinant human ACAT1/T2 enzyme kinetics and crystal structures","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact quote from the accompanying curation document, not from publisher text. Original study references: [haapalainen2007] Crystallographic and kinetic studies of human mitochondrial acetoacetyl-CoA thiolase: the importance of potassium and chloride ions for its structure and function (2007). https://pubmed.ncbi.nlm.nih.gov/17371050/ DOI: 10.1021/bi6026192","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"7633bde7-dcc9-5086-91c6-a45eb96857f3","stable_key":"import-c3df3634-4c3a-5099-a5d9-e4f6344c1084","title":"L-Lysine: mechanism-first literature curation (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"93998d47c21525409ba82f1c82ededf2893dff15fbe61c7deffc175b0e298e97","revision_id":"3897e31f-6624-59e1-a053-8a81b7361632","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}