{"id":"82dfa996-9bde-5ab9-9a73-803a36c08377","stable_key":"be889add-cec8-500b-be89-676431432a70:mn-gly-b4galt-donor-conformation","predicate":"induces","statement":"In the manganese-containing bovine B4GALT1 complex, donor binding reorganized residues 345–365 and Trp314, creating the sugar-acceptor pocket.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"75eb045d-7eae-5879-a3ad-bf56c1ef2c98","mechanism_event_label":"Loading the donor sugar helped prepare the enzyme to receive its target sugar chain.","subject":{"id":"a76bbd5b-08c9-5d74-8b6f-d69502ffa655","slug":"udp-galactose","display_name":"UDP-galactose","entity_type_key":"small_molecule"},"object":{"id":"40f5ec21-d2a9-58ea-98b9-4fd2ede70168","slug":"b4galt1-acceptor-site-formation","display_name":"B4GALT1 sugar-acceptor site formation","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"75eb045d-7eae-5879-a3ad-bf56c1ef2c98","stable_key":"be889add-cec8-500b-be89-676431432a70:mn-gly-b4galt-donor-conformation-event","event_type":"biochemical_relationship","label":"Loading the donor sugar helped prepare the enzyme to receive its target sugar chain.","description":"In the manganese-containing bovine B4GALT1 complex, donor binding reorganized residues 345–365 and Trp314, creating the sugar-acceptor pocket.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"99adbe92-fb01-5aae-ac3c-a904a32dd283","slug":"bovine-b4galt1","display_name":"Bovine beta-1,4-galactosyltransferase 1","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"a8082b11-c484-5792-bb81-48e8e699cbe4","slug":"manganese-ion","display_name":"Mn2+","entity_type_key":"ion"},"role":"bound_cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"a76bbd5b-08c9-5d74-8b6f-d69502ffa655","slug":"udp-galactose","display_name":"UDP-galactose","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"40f5ec21-d2a9-58ea-98b9-4fd2ede70168","slug":"b4galt1-acceptor-site-formation","display_name":"B4GALT1 sugar-acceptor site formation","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Bovine beta-1,4-galactosyltransferase 1 (enzyme); Manganese(II) ion (bound_cofactor)","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/manganese-glycosylation-sources/b4galt2002.abstract.txt\", \"locator\": \"Indexed primary abstract\", \"file_sha256\": \"343551452a01a412f22e9b1ca6765817b1a192a23107954294032effe3f0904b\", \"start_char\": 0, \"end_char\": 1632, \"text_sha256\": \"343551452a01a412f22e9b1ca6765817b1a192a23107954294032effe3f0904b\", \"text_characters\": 1632}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"2.8-angstrom crystal structure of the bovine B4GALT1 catalytic domain","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"UDP-galactose and MnCl2 in the crystallized complex.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This is bovine catalytic-domain evidence. A donor-bound structure does not determine human tissue manganese occupancy or clinical substrate limitation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Manganese research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"manganese","display_name":"Manganese","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Bos taurus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Loading the donor sugar helped prepare the enzyme to receive its target sugar chain.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mn-gly-b4galt2002] Crystal structure of beta1,4-galactosyltransferase complex with UDP-Gal reveals an oligosaccharide acceptor binding site. (2002). https://pubmed.ncbi.nlm.nih.gov/12051854/ DOI: 10.1016/s0022-2836(02)00020-7","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified recombinant enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"79cf5f0e-4bc6-53df-8740-bc18ec07928d","evidence_kind":"source_excerpt","locator":"Lines 726-738","start_line":726,"end_line":738,"excerpt":"### mn-gly-b4galt-donor-conformation\nIn the manganese-containing bovine B4GALT1 complex, donor binding reorganized residues 345–365 and Trp314, creating the sugar-acceptor pocket.\nCondition category: normal\nnutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Loading the donor sugar helped prepare the enzyme to receive its target sugar chain.\norganism: Bos taurus\ntissue_or_cell_type: Purified recombinant enzyme\nexperimental_model: 2.8-angstrom crystal structure of the bovine B4GALT1 catalytic domain\nlimitations: This is bovine catalytic-domain evidence. A donor-bound structure does not determine human tissue manganese occupancy or clinical substrate limitation.\nexposure: UDP-galactose and MnCl2 in the crystallized complex.\ncross_nutrient: Bovine beta-1,4-galactosyltransferase 1 (enzyme); Manganese(II) ion (bound_cofactor)\nevidence_span: {\"source_cache\": \"artifacts/manganese-glycosylation-sources/b4galt2002.abstract.txt\", \"locator\": \"Indexed primary abstract\", \"file_sha256\": \"343551452a01a412f22e9b1ca6765817b1a192a23107954294032effe3f0904b\", \"start_char\": 0, \"end_char\": 1632, \"text_sha256\": \"343551452a01a412f22e9b1ca6765817b1a192a23107954294032effe3f0904b\", \"text_characters\": 1632}\n[mn-gly-b4galt2002] Crystal structure of beta1,4-galactosyltransferase complex with UDP-Gal reveals an oligosaccharide acceptor binding site. (2002). https://pubmed.ncbi.nlm.nih.gov/12051854/ DOI: 10.1016/s0022-2836(02)00020-7","model_system":"2.8-angstrom crystal structure of the bovine B4GALT1 catalytic domain","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mn-gly-b4galt2002] Crystal structure of beta1,4-galactosyltransferase complex with UDP-Gal reveals an oligosaccharide acceptor binding site. (2002). https://pubmed.ncbi.nlm.nih.gov/12051854/ DOI: 10.1016/s0022-2836(02)00020-7","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"03224387-8a73-5b4f-906d-9f0be6625b7f","stable_key":"import-be889add-cec8-500b-be89-676431432a70","title":"Manganese: enzyme cofactors, glycosylation, transport 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":"f029ee5a1133a4f296047f06a6f0178deb9fd02e8d9707bc285bbe0f4e08fcb5","revision_id":"a77068c1-5a13-5aa9-bbac-d1cff6d34f15","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}