{"id":"1f298cee-8587-5285-8e3e-f90a1df78d94","stable_key":"31b1baa4-4113-5541-b9e7-fe44a5253a07:glyphosate-ecoli-aroa","predicate":"decreases_in_recorded_experiment","statement":"Glyphosate inhibited ecoli-aroa with an approximate purified-enzyme IC50 of 2.5 micromolar.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"21728cc5-9f47-5f25-b9fa-04e1155e11b6","mechanism_event_label":"Glyphosate inhibited ecoli-aroa with an approximate purified-enzyme IC50 of 2.5 micromolar.","subject":{"id":"aad546fc-b049-5f3c-b91a-2c5458873f29","slug":"glyphosate","display_name":"Glyphosate","entity_type_key":"small_molecule"},"object":{"id":"5b6fca80-44de-5da7-985f-8783f9302c24","slug":"ecoli-aroa","display_name":"Escherichia coli EPSP synthase / AroA","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"21728cc5-9f47-5f25-b9fa-04e1155e11b6","stable_key":"31b1baa4-4113-5541-b9e7-fe44a5253a07:glyphosate-ecoli-aroa-event","event_type":"biochemical_relationship","label":"Glyphosate inhibited ecoli-aroa with an approximate purified-enzyme IC50 of 2.5 micromolar.","description":"**EPSPS uses a second PEP molecule.** E. coli EPSPS (AroA) transfers an enolpyruvyl group from a second PEP molecule to shikimate-3-phosphate, making 5-enolpyruvylshikimate-3-phosphate (EPSP) and phosphate. Glyphosate inhibits this enzyme by occupying the PEP-associated substrate site in the substrate-bound enzyme. Purified-enzyme IC50 estimates were about 2.5 µM for E. coli EPSPS and 11 mM for CP4 EPSPS. These are not interchangeable microbial-growth thresholds or human intestinal effect concentrations. Adding shikimate upstream does not remove the need for EPSPS downstream. [Molecular basis for the herbicide resistance of Roundup Ready crops.](https://pubmed.ncbi.nlm.nih.gov/16916934/)","status":"provisional","compartment":null,"participants":[{"entity":{"id":"aad546fc-b049-5f3c-b91a-2c5458873f29","slug":"glyphosate","display_name":"Glyphosate","entity_type_key":"small_molecule"},"role":"tested factor","stoichiometry":null,"state_label":"Glyphosate titration","sequence_order":0,"notes":""},{"entity":{"id":"5b6fca80-44de-5da7-985f-8783f9302c24","slug":"ecoli-aroa","display_name":"Escherichia coli EPSP synthase / AroA","entity_type_key":"protein"},"role":"measured outcome","stoichiometry":null,"state_label":"decrease","sequence_order":1,"notes":""},{"entity":{"id":"20e5852c-38a1-54be-b486-d3d8083d9c2e","slug":"phosphoenolpyruvate","display_name":"Phosphoenolpyruvate / PEP","entity_type_key":"small_molecule"},"role":"competed substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ba13ffaa-56b5-5976-945c-71c0921defd8","slug":"shikimate-3-phosphate","display_name":"Shikimate 3-phosphate","entity_type_key":"small_molecule"},"role":"co-substrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full-text HTML and indexed abstract reviewed for the stated results; archived locally.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_contrast","value_text":"{\"intervention\": \"Glyphosate titration\", \"comparator\": \"Enzyme without glyphosate\", \"endpoint\": \"Glyphosate inhibited ecoli-aroa with an approximate purified-enzyme IC50 of 2.5 micromolar.\", \"effect_direction\": \"decrease\", \"combination\": \"single\", \"conditions\": []}","comparator":null,"unit":null,"notes":"Explicit extracted experimental comparison; source-derived draft.","entity":null},{"dimension":"experimental_model","value_text":"Purified enzyme comparison, Funke 2006.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"IC50 depends on assay conditions; not a growth threshold, dietary exposure limit or complete microbiome response.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Glyphosate inhibited ecoli-aroa with an approximate purified-enzyme IC50 of 2.5 micromolar.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Molecular basis for the herbicide resistance of Roundup Ready crops. | 2006 | DOI 10.1073/pnas.0603638103 | PMID 16916934 | https://pubmed.ncbi.nlm.nih.gov/16916934/ | https://doi.org/10.1073/pnas.0603638103 | https://pmc.ncbi.nlm.nih.gov/articles/PMC1559744/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 17-17; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"5da85d5c-b84d-55d3-b6c6-c92602358cdd","evidence_kind":"source_excerpt","locator":"Lines 17-17","start_line":17,"end_line":17,"excerpt":"**EPSPS uses a second PEP molecule.** E. coli EPSPS (AroA) transfers an enolpyruvyl group from a second PEP molecule to shikimate-3-phosphate, making 5-enolpyruvylshikimate-3-phosphate (EPSP) and phosphate. 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