{"id":"f511f388-349c-5bf3-8c42-289111277de3","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:ubiquitin-k48-chain","predicate":"forms_k48_linkages_in","statement":"Ubiquitin Gly76 can form an isopeptide bond to Lys48 of an adjacent ubiquitin in a chain.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"51362b46-589e-51d7-a850-661b4f8c797d","mechanism_event_label":"Protein-bound lysine can be an attachment site for a protein tag.","subject":{"id":"5ec8321b-83c6-5667-a571-fda04d84f1d0","slug":"ubiquitin","display_name":"Ubiquitin","entity_type_key":"protein"},"object":{"id":"32ed7b35-bab7-512f-ad67-cf1884828c25","slug":"ubiquitin-k48-polyubiquitin","display_name":"Lys48-linked polyubiquitin chains","entity_type_key":"protein_state"},"evidence_count":1,"mechanism_event":{"id":"51362b46-589e-51d7-a850-661b4f8c797d","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:ubiquitin-k48-chain-event","event_type":"biochemical_relationship","label":"Protein-bound lysine can be an attachment site for a protein tag.","description":"Ubiquitin Gly76 can form an isopeptide bond to Lys48 of an adjacent ubiquitin in a chain.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"5ec8321b-83c6-5667-a571-fda04d84f1d0","slug":"ubiquitin","display_name":"Ubiquitin","entity_type_key":"protein"},"role":"chain_building_block","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"32ed7b35-bab7-512f-ad67-cf1884828c25","slug":"ubiquitin-k48-polyubiquitin","display_name":"Lys48-linked polyubiquitin chains","entity_type_key":"protein_state"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Multiubiquitination of an experimentally targeted beta-galactosidase substrate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This describes one chain topology; ubiquitin has other linkages and not all ubiquitination means degradation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"Experimental ubiquitin-conjugation system","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Protein-bound lysine can be an attachment site for a protein tag.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ubiquitin-k48-1989] A multiubiquitin chain is confined to specific lysine in a targeted short-lived protein (1989). https://pubmed.ncbi.nlm.nih.gov/2538923/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Not specified as a whole tissue; see experimental model.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cba11793-7804-57e2-8f28-b20de099568c","evidence_kind":"source_excerpt","locator":"Lines 598-606","start_line":598,"end_line":606,"excerpt":"### ubiquitin-k48-chain\nUbiquitin Gly76 can form an isopeptide bond to Lys48 of an adjacent ubiquitin in a chain.\nPlain language: Protein-bound lysine can be an attachment site for a protein tag.\nCondition category: normal\norganism: Experimental ubiquitin-conjugation system\ntissue_or_cell_type: Not specified as a whole tissue; see experimental model.\nexperimental_model: Multiubiquitination of an experimentally targeted beta-galactosidase substrate.\nlimitations: This describes one chain topology; ubiquitin has other linkages and not all ubiquitination means degradation.\n[ubiquitin-k48-1989] A multiubiquitin chain is confined to specific lysine in a targeted short-lived protein (1989). https://pubmed.ncbi.nlm.nih.gov/2538923/","model_system":"Multiubiquitination of an experimentally targeted beta-galactosidase substrate.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact quote from the accompanying curation document, not from publisher text. Original study references: [ubiquitin-k48-1989] A multiubiquitin chain is confined to specific lysine in a targeted short-lived protein (1989). https://pubmed.ncbi.nlm.nih.gov/2538923/","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}