{"id":"021155ca-f0bf-5a33-914d-27ed0939f0db","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-pknd-negative","predicate":"did_not_phosphorylate","statement":"The 2020 reexamination found that Mycobacterium tuberculosis EgtD was not a PknD substrate under its in vitro conditions.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"0970f33e-28b4-50e5-aed5-c55cea46f93c","mechanism_event_label":"A later study did not reproduce the proposed kinase reaction.","subject":{"id":"e3b9deb4-28e3-5ffd-93d9-b5cf2b4a7763","slug":"mycobacterium-tuberculosis-pknd","display_name":"Mycobacterium tuberculosis protein kinase PknD","entity_type_key":"protein"},"object":{"id":"53556332-10bc-5b52-985d-4c703fd44543","slug":"mycobacterium-tuberculosis-egtd","display_name":"Mycobacterium tuberculosis EgtD / Rv3701c","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"0970f33e-28b4-50e5-aed5-c55cea46f93c","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-pknd-negative-event","event_type":"observed_relationship","label":"A later study did not reproduce the proposed kinase reaction.","description":"The 2020 reexamination found that Mycobacterium tuberculosis EgtD was not a PknD substrate under its in vitro conditions.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e3b9deb4-28e3-5ffd-93d9-b5cf2b4a7763","slug":"mycobacterium-tuberculosis-pknd","display_name":"Mycobacterium tuberculosis protein kinase PknD","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"53556332-10bc-5b52-985d-4c703fd44543","slug":"mycobacterium-tuberculosis-egtd","display_name":"Mycobacterium tuberculosis EgtD / Rv3701c","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"939c92c3-50ea-5a4a-9654-8e3b94448132","slug":"ergothioneine","display_name":"L-Ergothioneine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"In vitro kinase reassessment; active-site accessibility considered structurally.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"A negative in vitro result does not alone exclude every cellular condition; matched protocols are needed.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Ergothioneine collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"ergothioneine","display_name":"L-Ergothioneine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A later study did not reproduce the proposed kinase reaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Reexamination of the Ergothioneine Biosynthetic Methyltransferase EgtD from Mycobacterium tuberculosis as a Protein Kinase Substrate. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32614492/ · DOI 10.1002/cbic.202000232","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"8156cd3b-020a-53c0-8f9a-cc1d385a5f71","evidence_kind":"source_excerpt","locator":"Lines 584-590","start_line":584,"end_line":590,"excerpt":"## ergothioneine-pknd-negative\nA later study did not reproduce the proposed kinase reaction.\nThe 2020 reexamination found that Mycobacterium tuberculosis EgtD was not a PknD substrate under its in vitro conditions.\nModel: In vitro kinase reassessment; active-site accessibility considered structurally.\nLimitations: A negative in vitro result does not alone exclude every cellular condition; matched protocols are needed.\nEvidence access: Primary abstract\nReexamination of the Ergothioneine Biosynthetic Methyltransferase EgtD from Mycobacterium tuberculosis as a Protein Kinase Substrate. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32614492/ · DOI 10.1002/cbic.202000232","model_system":"In vitro kinase reassessment; active-site accessibility considered structurally.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"2f037d98-f3d0-5dbe-80d8-90b738f130d6","stable_key":"import-59b18080-c560-563d-abc5-bac4ee82a27c","title":"Ergothioneine: transport, redox chemistry and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"b6def8119f03cfabeec2fb55ba924340dc612e1dd42f05404201fa2b7ced5259","revision_id":"f88c38e6-ffb5-5a68-83ca-4610ca2c2df4","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"aeb40961-7532-514a-b700-f23ef30fe3cb","title":"Does PknD phosphorylate EgtD to regulate microbial ergothioneine synthesis?","kind":"contradiction","status":"open","why":"The 2015 primary study reported PknD-dependent EgtD Thr213 phosphorylation in vitro and in a cell-based system. The 2020 primary reexamination directly tested and rejected EgtD as a PknD substrate under its in vitro conditions. This is a research disagreement, not correction of ledger wording.","resolution":"Unresolved. Retain both findings and treat physiological PknD-to-EgtD regulation as disputed. Compare protein constructs, kinase activity controls, folding, substrate occupancy, phosphosite measurements and cellular context. These are candidate explanations, not established causes of the discrepancy; T213E substitution alone does not prove phosphorylation.","created_at":"2026-09-19 08:02:29","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/aeb40961-7532-514a-b700-f23ef30fe3cb","sides":[{"conflict_id":"aeb40961-7532-514a-b700-f23ef30fe3cb","ordinal":0,"label":"2015 reported phosphorylation","revision_id":"f88c38e6-ffb5-5a68-83ca-4610ca2c2df4","start_line":576,"end_line":582,"quote":"## ergothioneine-pknd-positive\nOne study reported a kinase-controlled synthesis switch.\nThe 2015 Mycobacterium tuberculosis study reported PknD phosphorylation of EgtD at Thr213 in vitro and in a cell-based system.\nModel: Bacterial kinase assays and cell-based phosphorylation evidence.\nLimitations: The kinase-substrate assignment was directly challenged by the 2020 reexamination; not settled regulation.\nEvidence access: Primary abstract\nRegulation of Ergothioneine Biosynthesis and Its Effect on Mycobacterium tuberculosis Growth and Infectivity. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26229105/ · DOI 10.1074/jbc.M115.648642","source_key":"import-59b18080-c560-563d-abc5-bac4ee82a27c","source_title":"Ergothioneine: transport, redox chemistry and cross-nutrient mechanisms (2026-09-19)","claim_ids":["2112a4b5-e7a2-5704-9cc7-23f5256c8b09"]},{"conflict_id":"aeb40961-7532-514a-b700-f23ef30fe3cb","ordinal":1,"label":"2020 in vitro reexamination","revision_id":"f88c38e6-ffb5-5a68-83ca-4610ca2c2df4","start_line":584,"end_line":590,"quote":"## ergothioneine-pknd-negative\nA later study did not reproduce the proposed kinase reaction.\nThe 2020 reexamination found that Mycobacterium tuberculosis EgtD was not a PknD substrate under its in vitro conditions.\nModel: In vitro kinase reassessment; active-site accessibility considered structurally.\nLimitations: A negative in vitro result does not alone exclude every cellular condition; matched protocols are needed.\nEvidence access: Primary abstract\nReexamination of the Ergothioneine Biosynthetic Methyltransferase EgtD from Mycobacterium tuberculosis as a Protein Kinase Substrate. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32614492/ · DOI 10.1002/cbic.202000232","source_key":"import-59b18080-c560-563d-abc5-bac4ee82a27c","source_title":"Ergothioneine: transport, redox chemistry and cross-nutrient mechanisms (2026-09-19)","claim_ids":["021155ca-f0bf-5a33-914d-27ed0939f0db"]}]}],"corrections":[],"research":null}