{"id":"def5ed01-886d-58df-92d4-6e2855d77909","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-mocos-plp","predicate":"is_bound_cofactor_of","statement":"The purified human MOCOS NifS-like domain bound PLP and exhibited cysteine desulfurase activity.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"9fd9cb39-017d-596f-abea-730cab389bc7","mechanism_event_label":"Vitamin B6 chemistry helps supply the sulfur used to activate these molybdenum enzymes.","subject":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"object":{"id":"e8016ea8-2237-5618-85b2-199710521dc6","slug":"mocos","display_name":"Human molybdenum cofactor sulfurase / MOCOS","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"9fd9cb39-017d-596f-abea-730cab389bc7","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-mocos-plp-event","event_type":"biochemical_relationship","label":"Vitamin B6 chemistry helps supply the sulfur used to activate these molybdenum enzymes.","description":"The purified human MOCOS NifS-like domain bound PLP and exhibited cysteine desulfurase activity.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ca899f13-50ad-55e5-ab99-329ae0038c74","slug":"l-cysteine","display_name":"L-Cysteine","entity_type_key":"small_molecule"},"role":"sulfur substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e8016ea8-2237-5618-85b2-199710521dc6","slug":"mocos","display_name":"Human molybdenum cofactor sulfurase / MOCOS","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/molybdenum-research/34356852.fulltext.txt\", \"locator\": \"Exact primary full-text span; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"8bf3a09c4f88994cf8adc50faf391e62ac27e7572e59e6606147f2c689212d07\", \"start_char\": 41304, \"end_char\": 42029, \"text_sha256\": \"b9b02aae5eb537bdffc178ceaa33177cef6448738c19cb1a8477ad543f4e970c\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Xanthinuria families with recombinant human MOCOS-domain assays and a plant XDH homolog assay","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"PLP quantification, cysteine desulfurase assays and Moco/MPT binding","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Human XDH C150F was functionally modeled using Arabidopsis XDH1 C161S, not purified human C150F; MOCOS assays used isolated domains.","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":"Human genetics and human MOCOS proteins; plant XDH variant experiment separately","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Vitamin B6 chemistry helps supply the sulfur used to activate these molybdenum enzymes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mo-p34356852] Classical Xanthinuria in Nine Israeli Families and Two Isolated Cases from Germany: Molecular, Biochemical and Population Genetics Aspects. (2021). https://pubmed.ncbi.nlm.nih.gov/34356852/ DOI: 10.3390/biomedicines9070788","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Patient samples and purified domains","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d0a8edb8-631f-5365-9e67-b9327bad9f06","evidence_kind":"source_excerpt","locator":"Lines 534-545","start_line":534,"end_line":545,"excerpt":"### mo-mocos-plp\nThe purified human MOCOS NifS-like domain bound PLP and exhibited cysteine desulfurase activity.\nCondition category: normal\nnutrient_topic: Molybdenum research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Vitamin B6 chemistry helps supply the sulfur used to activate these molybdenum enzymes.\norganism: Human genetics and human MOCOS proteins; plant XDH variant experiment separately\ntissue_or_cell_type: Patient samples and purified domains\nexperimental_model: Xanthinuria families with recombinant human MOCOS-domain assays and a plant XDH homolog assay\nlimitations: Human XDH C150F was functionally modeled using Arabidopsis XDH1 C161S, not purified human C150F; MOCOS assays used isolated domains.\nexposure: PLP quantification, cysteine desulfurase assays and Moco/MPT binding\nevidence_span: {\"source_cache\": \"artifacts/molybdenum-research/34356852.fulltext.txt\", \"locator\": \"Exact primary full-text span; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"8bf3a09c4f88994cf8adc50faf391e62ac27e7572e59e6606147f2c689212d07\", \"start_char\": 41304, \"end_char\": 42029, \"text_sha256\": \"b9b02aae5eb537bdffc178ceaa33177cef6448738c19cb1a8477ad543f4e970c\"}\n[mo-p34356852] Classical Xanthinuria in Nine Israeli Families and Two Isolated Cases from Germany: Molecular, Biochemical and Population Genetics Aspects. (2021). https://pubmed.ncbi.nlm.nih.gov/34356852/ DOI: 10.3390/biomedicines9070788","model_system":"Xanthinuria families with recombinant human MOCOS-domain assays and a plant XDH homolog assay","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mo-p34356852] Classical Xanthinuria in Nine Israeli Families and Two Isolated Cases from Germany: Molecular, Biochemical and Population Genetics Aspects. (2021). https://pubmed.ncbi.nlm.nih.gov/34356852/ DOI: 10.3390/biomedicines9070788","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. Not publisher full text.","file_path":"","sha256":"143147eb9ac7fe750bdd33bb50d7773bc0cd49cc94faf219aebce3c3d760dd8f","revision_id":"90c2239d-290b-5e16-815a-f94d30569ebd","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}