{"id":"4a7613bc-bc82-5f96-85e4-c0ab0101e6e2","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-marc-c273a","predicate":"abolishes_assayed_formation_of","statement":"The C273A mARC1 variant abolished nitrite-dependent NO formation.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"06a30835-4d93-5075-b56e-43e33d6e6714","mechanism_event_label":"The molybdenum-binding cysteine is critical for this reaction.","subject":{"id":"46d6b3d3-34f4-5bde-a686-0c77b7b33f33","slug":"mtarc1-c273a","display_name":"Human MTARC1 p.Cys273Ala","entity_type_key":"protein_state"},"object":{"id":"f2a6b7ab-ad41-5ada-8895-41d6ce42f4e4","slug":"nitric-oxide","display_name":"NO","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"06a30835-4d93-5075-b56e-43e33d6e6714","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-marc-c273a-event","event_type":"biochemical_relationship","label":"The molybdenum-binding cysteine is critical for this reaction.","description":"The C273A mARC1 variant abolished nitrite-dependent NO formation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"46d6b3d3-34f4-5bde-a686-0c77b7b33f33","slug":"mtarc1-c273a","display_name":"Human MTARC1 p.Cys273Ala","entity_type_key":"protein_state"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"f2a6b7ab-ad41-5ada-8895-41d6ce42f4e4","slug":"nitric-oxide","display_name":"NO","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/molybdenum-research/24500710.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e4c2ab41c945d420266290d0241752039d7de2cb6223f9c64c7d0525c5688d9b\", \"start_char\": 0, \"end_char\": 1585, \"text_sha256\": \"e4c2ab41c945d420266290d0241752039d7de2cb6223f9c64c7d0525c5688d9b\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human mARC1/mARC2, active-site mutation, tungsten replacement and HEK expression","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Reduced enzyme, nitrite, NADH/CYB5/CYB5R; pH 7.5 versus 6.5","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Shows nitrite-reducing capacity; its share of NO production in normal people and response to mineral intake are not established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Molybdenum research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"molybdenum","display_name":"Molybdenum","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens proteins and HEK cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The molybdenum-binding cysteine is critical for this reaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mo-p24500710] Nitrite reductase and nitric-oxide synthase activity of the mitochondrial molybdopterin enzymes mARC1 and mARC2. (2014). https://pubmed.ncbi.nlm.nih.gov/24500710/ DOI: 10.1074/jbc.m114.555177","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified redox system and human cell model","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":"70d07625-33e9-5264-a3cf-12468c118263","evidence_kind":"source_excerpt","locator":"Lines 1067-1078","start_line":1067,"end_line":1078,"excerpt":"### mo-marc-c273a\nThe C273A mARC1 variant abolished nitrite-dependent NO formation.\nCondition category: machinery_impairment\nnutrient_topic: Molybdenum research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The molybdenum-binding cysteine is critical for this reaction.\norganism: Homo sapiens proteins and HEK cells\ntissue_or_cell_type: Purified redox system and human cell model\nexperimental_model: Recombinant human mARC1/mARC2, active-site mutation, tungsten replacement and HEK expression\nlimitations: Shows nitrite-reducing capacity; its share of NO production in normal people and response to mineral intake are not established.\nexposure: Reduced enzyme, nitrite, NADH/CYB5/CYB5R; pH 7.5 versus 6.5\nevidence_span: {\"source_cache\": \"artifacts/molybdenum-research/24500710.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e4c2ab41c945d420266290d0241752039d7de2cb6223f9c64c7d0525c5688d9b\", \"start_char\": 0, \"end_char\": 1585, \"text_sha256\": \"e4c2ab41c945d420266290d0241752039d7de2cb6223f9c64c7d0525c5688d9b\"}\n[mo-p24500710] Nitrite reductase and nitric-oxide synthase activity of the mitochondrial molybdopterin enzymes mARC1 and mARC2. (2014). https://pubmed.ncbi.nlm.nih.gov/24500710/ DOI: 10.1074/jbc.m114.555177","model_system":"Recombinant human mARC1/mARC2, active-site mutation, tungsten replacement and HEK expression","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mo-p24500710] Nitrite reductase and nitric-oxide synthase activity of the mitochondrial molybdopterin enzymes mARC1 and mARC2. (2014). https://pubmed.ncbi.nlm.nih.gov/24500710/ DOI: 10.1074/jbc.m114.555177","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"1aa6da60-8284-5252-8dd9-ac2250d5ced5","stable_key":"import-dc8975b1-95ff-5d9b-be17-a1c04610cca7","title":"Molybdenum: cofactor assembly, sulfur metabolism and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. 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