{"id":"1d8dd92d-d7c6-5450-b5ad-29a2ac49bbb5","stable_key":"6612c190-1948-5bcf-bbe3-a7f6c50fa3cf:l-proline-microbial-stereospecificity","predicate":"reduces","statement":"Purified C. difficile proline reductase contained PrdA and selenocysteine-containing PrdB and used D-proline; its stereospecific activity is distinct from human L-proline oxidation.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"6d1bfab9-73ed-5817-8562-f559b04158b0","mechanism_event_label":"Gut bacteria can use a different form of proline with different machinery.","subject":{"id":"e6885988-faae-5f4f-972b-9931b65d5e17","slug":"c-difficile-proline-reductase","display_name":"Clostridioides difficile D-proline reductase complex","entity_type_key":"protein_complex"},"object":{"id":"6459a2bf-7e42-5037-a0b1-51d72a0c5845","slug":"d-proline","display_name":"D-Proline","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"6d1bfab9-73ed-5817-8562-f559b04158b0","stable_key":"6612c190-1948-5bcf-bbe3-a7f6c50fa3cf:l-proline-microbial-stereospecificity-event","event_type":"observed_relationship","label":"Gut bacteria can use a different form of proline with different machinery.","description":"Purified C. difficile proline reductase contained PrdA and selenocysteine-containing PrdB and used D-proline; its stereospecific activity is distinct from human L-proline oxidation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e6885988-faae-5f4f-972b-9931b65d5e17","slug":"c-difficile-proline-reductase","display_name":"Clostridioides difficile D-proline reductase complex","entity_type_key":"protein_complex"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"6459a2bf-7e42-5037-a0b1-51d72a0c5845","slug":"d-proline","display_name":"D-Proline","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"70ccd53c-83ad-5251-a4f5-6370973bc40a","slug":"l-proline","display_name":"L-Proline","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"63546ce7-77dc-541b-8dd6-d8b7963d59aa","slug":"c-difficile-prda","display_name":"Clostridioides difficile PrdA","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"7fd2d70e-23d9-50a1-bad6-bfb99c970649","slug":"c-difficile-prdb","display_name":"Clostridioides difficile selenoprotein PrdB","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified bacterial reductase and substrate tests.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"L-proline-linked fermentation requires stereochemical processing; this enzyme is not a human PRODH isoform.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Proline collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-proline","display_name":"L-Proline","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Gut bacteria can use a different form of proline with different machinery.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Analysis of proline reduction in the nosocomial pathogen Clostridium difficile. · 2006 · https://pubmed.ncbi.nlm.nih.gov/17041035/ · DOI 10.1128/JB.01370-06","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"1e391fe8-f0b3-5d45-9900-3c3c96d42ab6","evidence_kind":"source_excerpt","locator":"Lines 406-412","start_line":406,"end_line":412,"excerpt":"## l-proline-microbial-stereospecificity\nGut bacteria can use a different form of proline with different machinery.\nPurified C. difficile proline reductase contained PrdA and selenocysteine-containing PrdB and used D-proline; its stereospecific activity is distinct from human L-proline oxidation.\nModel: Purified bacterial reductase and substrate tests.\nLimitations: L-proline-linked fermentation requires stereochemical processing; this enzyme is not a human PRODH isoform.\nEvidence access: Primary abstract\nAnalysis of proline reduction in the nosocomial pathogen Clostridium difficile. · 2006 · https://pubmed.ncbi.nlm.nih.gov/17041035/ · DOI 10.1128/JB.01370-06","model_system":"Purified bacterial reductase and substrate tests.","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":"e5aa7fc5-ee52-5376-8169-416082a89fd1","stable_key":"import-6612c190-1948-5bcf-bbe3-a7f6c50fa3cf","title":"L-Proline: synthesis, collagen processing, redox metabolism 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":"7b7f1981f9c7897fbb6baa19425bdc19dede78ad4d66fa554394b8337c7366fb","revision_id":"4971a925-fa70-59f8-8030-d3029a18a62f","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}