{"gene":"PF3D7_API02900","run_date":"2026-09-08T15:24:04","timeline":{"discoveries":[{"year":2005,"finding":"TUFA (PF3D7_API02900) protein (EF-Tu) is translated within the P. falciparum apicoplast and localizes to that organelle; expression peaks in the trophozoite stage of the intraerythrocytic cycle. The drug thiostrepton, which binds apicoplast LSU rRNA, reduces apicoplast EF-Tu levels, supporting translation in the apicoplast as thiostrepton's site of action.","method":"Immunolocalization of EF-Tu protein to the apicoplast; Western blot of stage-specific expression; thiostrepton drug treatment followed by EF-Tu protein quantification","journal":"Molecular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct protein localization to organelle with functional drug-treatment experiment; single lab with two orthogonal methods (immunolocalization + drug-response Western blot)","pmids":["15773980"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1999,"finding":"TUFA (PF3D7_API02900) encodes a GTP-dependent translation elongation factor (EF-Tu) in the P. falciparum plastid organelle. Recombinant P. falciparum EF-Tu forms demonstrable in vitro complexes with the antibiotics kirromycin, GE2270A, and enacyloxin IIa, which bind to different sites on the protein; these inhibitors all show antimalarial activity in blood cultures.","method":"In vitro complex formation between recombinant EF-Tu and structurally distinct antibiotic inhibitors; blood culture antimalarial activity assays","journal":"Protist","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — recombinant protein in vitro binding assay with multiple inhibitors binding different sites; single lab","pmids":["10505418"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2010,"finding":"TUFA (PF3D7_API02900) encodes an apicoplast EF-Tu in P. falciparum that hydrolyses GTP and physically interacts with the nuclear-encoded elongation factor EF-Ts (PfEF-Ts). PfEF-Ts mediates nucleotide (GDP) exchange on PfEF-Tu. The EF-Tu inhibitor kirromycin affects PfEF-Tu GTPase activity in vitro, confirming apicoplast EF-Tu as kirromycin's target. Homology modelling reveals PfEF-Ts-induced structural alterations that would facilitate GDP release. Additionally, PfEF-Tu possesses chaperone-related disulphide reductase activity, providing a rationale for retention of the tufA gene on the plastid genome.","method":"Recombinant protein GTPase assay; Co-immunoprecipitation / binding interaction between recombinant PfEF-Tu and PfEF-Ts; nucleotide exchange assay; kirromycin inhibition in vitro; homology modelling; GFP-leader-sequence targeting assay for EF-Ts","journal":"International journal for parasitology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal in vitro assays (GTPase activity, nucleotide exchange, inhibitor effect, chaperone activity) plus structural modelling and localization, single lab but rigorous multi-method study","pmids":["21163263"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2015,"finding":"Clarithromycin downregulates TUFA (PF3D7_API02900) mRNA and protein expression in P. falciparum, consistent with disruption of apicoplast translation as its mechanism of antimalarial action.","method":"qPCR for tufA mRNA; Western blotting for EF-Tu protein after clarithromycin treatment in Pf3D7 and PfK1 strains","journal":"Life sciences","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, two related methods (qPCR + Western blot) but no mechanistic dissection of how clarithromycin affects apicoplast translation; limited controls","pmids":["26164186"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":1997,"finding":"Phylogenetic analysis of the tufA gene from the 35-kb apicoplast genome of P. falciparum (and coccidians) grouped the organellar genome with cyanobacteria and green algal plastids, establishing the apicoplast as a secondary endosymbiotic plastid of probable green algal origin and placing tufA on the apicoplast (plastid) genome.","method":"In situ hybridization to localize the 35-kb DNA to a four-membrane organelle in Toxoplasma gondii; phylogenetic analysis of tufA gene sequences from P. falciparum, T. gondii, and E. tenella","journal":"Science (New York, N.Y.)","confidence":"Medium","confidence_rationale":"Tier 2 / Strong — direct in situ hybridization localization of the genome plus phylogenetic analysis; replicated across multiple apicomplexan species; establishes genomic location of tufA","pmids":["9045615"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"TUFA (PF3D7_API02900) encodes the apicoplast-genome-encoded translation elongation factor Tu (EF-Tu) of Plasmodium falciparum; it is expressed at the protein level within the apicoplast (peaking in trophozoites), hydrolyses GTP, interacts with the nuclear-encoded EF-Ts partner to catalyse GDP/GTP nucleotide exchange, possesses chaperone-related disulphide reductase activity, and is the direct molecular target of antibiotics including kirromycin, GE2270A, enacyloxin IIa, and is functionally suppressed by thiostrepton and clarithromycin."},"narrative":{"mechanistic_narrative":"TUFA (PF3D7_API02900) is the apicoplast-genome-encoded translation elongation factor Tu (EF-Tu) of Plasmodium falciparum, and it functions in protein synthesis within the apicoplast, the organelle to which its protein product localizes and in which it is translated, with expression peaking in the trophozoite stage [PMID:15773980, PMID:9045615]. As a canonical elongation factor, recombinant PfEF-Tu hydrolyses GTP and undergoes GDP/GTP nucleotide exchange catalysed by its physical partner, the nuclear-encoded EF-Ts (PfEF-Ts), whose binding induces structural changes that would promote GDP release [PMID:21163263]. Beyond its translation role, PfEF-Tu carries a chaperone-related disulphide reductase activity, a property advanced as a rationale for retention of the tufA gene on the plastid genome [PMID:21163263]. TUFA is the direct molecular target of structurally distinct antibiotics: recombinant PfEF-Tu forms in vitro complexes with kirromycin, GE2270A, and enacyloxin IIa at different sites, and kirromycin inhibits its GTPase activity, while apicoplast-translation-disrupting drugs thiostrepton and clarithromycin reduce EF-Tu expression [PMID:15773980, PMID:10505418, PMID:21163263, PMID:26164186]. All of these inhibitors show antimalarial activity, marking apicoplast translation via TUFA as an antimalarial vulnerability [PMID:10505418].","teleology":[{"year":1997,"claim":"Establishing where tufA physically resides answered whether this elongation factor belongs to the parasite's organellar genome and clarified the evolutionary origin of that genome.","evidence":"In situ hybridization localizing the 35-kb DNA to a four-membrane organelle and phylogenetic analysis of tufA sequences across apicomplexans","pmids":["9045615"],"confidence":"Medium","gaps":["Does not demonstrate that the tufA-encoded protein is functional as an elongation factor","No evidence on protein localization or expression timing","No functional or drug-target data"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1999,"claim":"Identifying that recombinant PfEF-Tu binds structurally distinct antibiotics at different sites established the protein as a druggable antimalarial target, not merely a genomic feature.","evidence":"In vitro complex formation of recombinant EF-Tu with kirromycin, GE2270A, and enacyloxin IIa, plus blood-culture antimalarial assays","pmids":["10505418"],"confidence":"Medium","gaps":["Binding shown in vitro but effect on EF-Tu catalytic activity not measured here","Single lab; no structural mapping of binding sites","No demonstration that antimalarial activity operates through EF-Tu inhibition in vivo"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2005,"claim":"Localizing the EF-Tu protein and its stage-specific expression answered whether tufA is translated and functions inside the apicoplast, linking it to thiostrepton's site of action.","evidence":"Immunolocalization to the apicoplast, stage-specific Western blots, and EF-Tu quantification after thiostrepton treatment","pmids":["15773980"],"confidence":"Medium","gaps":["Reduction of EF-Tu by thiostrepton is indirect (via rRNA binding), not direct drug-EF-Tu interaction","Does not resolve EF-Tu catalytic mechanism","Single-lab evidence"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2010,"claim":"Reconstituting the catalytic cycle answered how PfEF-Tu operates enzymatically and with which partner, and confirmed kirromycin acts on its GTPase, while revealing an unexpected chaperone activity.","evidence":"Recombinant GTPase and nucleotide-exchange assays, PfEF-Tu/PfEF-Ts interaction, kirromycin inhibition in vitro, homology modelling, and GFP-leader targeting of EF-Ts","pmids":["21163263"],"confidence":"High","gaps":["Structural model of the EF-Tu/EF-Ts complex is homology-based, not experimentally determined","Physiological substrates of the disulphide reductase activity not identified","In vivo consequences of blocking nucleotide exchange not tested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2015,"claim":"Testing clarithromycin's effect on TUFA expression addressed whether this macrolide's antimalarial action operates through disruption of apicoplast translation.","evidence":"qPCR and Western blotting of tufA mRNA and EF-Tu protein after clarithromycin treatment in Pf3D7 and PfK1 strains","pmids":["26164186"],"confidence":"Low","gaps":["No mechanistic dissection of how clarithromycin affects apicoplast translation; limited controls","Downregulation may be a downstream consequence rather than a direct effect on TUFA","Effect on EF-Tu catalytic function not measured"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":null,"claim":"The in vivo essentiality of TUFA and the native substrates of its chaperone-related disulphide reductase activity remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No genetic knockout or conditional depletion of tufA reported in the corpus","No experimentally determined structure of PfEF-Tu or its complex with EF-Ts","Physiological targets and biological role of the disulphide reductase activity unknown"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["PfEF-Tu / PfEF-Ts (nucleotide-exchange) complex [#2]"],"partners":["PFEF-TS (NUCLEAR-ENCODED ELONGATION FACTOR TS) [#2]"],"other_free_text":["Direct in vitro binding target of kirromycin, GE2270A, and enacyloxin IIa at distinct sites; kirromycin inhibits its GTPase activity [#1, #2]","EF-Tu protein levels reduced by thiostrepton and clarithromycin, consistent with disruption of apicoplast translation [#0, #3]","Encoded on the 35-kb apicoplast (plastid) genome of green algal secondary-endosymbiotic origin [#4]","Expression peaks in the trophozoite stage of the intraerythrocytic cycle [#0]","Possesses chaperone-related disulphide reductase activity, offered as a rationale for retaining tufA on the plastid genome [#2]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"9045615","id":"PMC_9045615","title":"A plastid of probable green algal origin in Apicomplexan parasites.","date":"1997","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/9045615","citation_count":544,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"15684081","id":"PMC_15684081","title":"A monkey's tale: the origin of Plasmodium vivax as a human malaria parasite.","date":"2005","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/15684081","citation_count":158,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["elongation factor Tu"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"20498054","id":"PMC_20498054","title":"African apes as reservoirs of Plasmodium falciparum and the origin and diversification of the Laverania subgenus.","date":"2010","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/20498054","citation_count":117,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"16765106","id":"PMC_16765106","title":"The phylogeny of rodent malaria parasites: simultaneous analysis across three genomes.","date":"2006","source":"Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/16765106","citation_count":65,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"15773980","id":"PMC_15773980","title":"The apicoplast of Plasmodium falciparum is translationally active.","date":"2005","source":"Molecular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/15773980","citation_count":59,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA","elongation factor Tu"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"10505418","id":"PMC_10505418","title":"Antibiotic inhibitors of organellar protein synthesis in Plasmodium falciparum.","date":"1999","source":"Protist","url":"https://pubmed.ncbi.nlm.nih.gov/10505418","citation_count":56,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["elongation factor Tu"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"26577930","id":"PMC_26577930","title":"Molecular characterization of misidentified Plasmodium ovale imported cases in Singapore.","date":"2015","source":"Malaria journal","url":"https://pubmed.ncbi.nlm.nih.gov/26577930","citation_count":33,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"21163263","id":"PMC_21163263","title":"Interaction of apicoplast-encoded elongation factor (EF) EF-Tu with nuclear-encoded EF-Ts mediates translation in the Plasmodiumfalciparum plastid.","date":"2010","source":"International journal for parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/21163263","citation_count":17,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"19818838","id":"PMC_19818838","title":"Phylogeny of Asian primate malaria parasites inferred from apicoplast genome-encoded genes with special emphasis on the positions of Plasmodium vivax and P. fragile.","date":"2010","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/19818838","citation_count":17,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["elongation factor Tu"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"22266119","id":"PMC_22266119","title":"Plasmodium vivax apicoplast genome: a comparative analysis of major genes from Indian field isolates.","date":"2012","source":"Acta tropica","url":"https://pubmed.ncbi.nlm.nih.gov/22266119","citation_count":10,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"17602895","id":"PMC_17602895","title":"Analysis of elongation factor Tu (tuf A) of apicoplast from Indian Plasmodium vivax isolates.","date":"2007","source":"Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/17602895","citation_count":9,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["elongation factor Tu"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"26164186","id":"PMC_26164186","title":"Clarithromycin enhances the antimalarial efficacy of mefloquine via its increased bioavailability and disrupting P. falciparum apicoplast.","date":"2015","source":"Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/26164186","citation_count":3,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["TUFA"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8811,"output_tokens":1766,"usd":0.026461,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6806,"output_tokens":2920,"usd":0.053515,"stage2_stop_reason":"end_turn"},"total_usd":0.079976,"stage1_batch_id":"msgbatch_01S4WrhSkksYHeZXxqf3za3o","stage2_batch_id":"msgbatch_019VBBeuW6G52X8gZfsFDfb5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2005,\n      \"finding\": \"TUFA (PF3D7_API02900) protein (EF-Tu) is translated within the P. falciparum apicoplast and localizes to that organelle; expression peaks in the trophozoite stage of the intraerythrocytic cycle. The drug thiostrepton, which binds apicoplast LSU rRNA, reduces apicoplast EF-Tu levels, supporting translation in the apicoplast as thiostrepton's site of action.\",\n      \"method\": \"Immunolocalization of EF-Tu protein to the apicoplast; Western blot of stage-specific expression; thiostrepton drug treatment followed by EF-Tu protein quantification\",\n      \"journal\": \"Molecular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct protein localization to organelle with functional drug-treatment experiment; single lab with two orthogonal methods (immunolocalization + drug-response Western blot)\",\n      \"pmids\": [\"15773980\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"TUFA (PF3D7_API02900) encodes a GTP-dependent translation elongation factor (EF-Tu) in the P. falciparum plastid organelle. Recombinant P. falciparum EF-Tu forms demonstrable in vitro complexes with the antibiotics kirromycin, GE2270A, and enacyloxin IIa, which bind to different sites on the protein; these inhibitors all show antimalarial activity in blood cultures.\",\n      \"method\": \"In vitro complex formation between recombinant EF-Tu and structurally distinct antibiotic inhibitors; blood culture antimalarial activity assays\",\n      \"journal\": \"Protist\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — recombinant protein in vitro binding assay with multiple inhibitors binding different sites; single lab\",\n      \"pmids\": [\"10505418\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"TUFA (PF3D7_API02900) encodes an apicoplast EF-Tu in P. falciparum that hydrolyses GTP and physically interacts with the nuclear-encoded elongation factor EF-Ts (PfEF-Ts). PfEF-Ts mediates nucleotide (GDP) exchange on PfEF-Tu. The EF-Tu inhibitor kirromycin affects PfEF-Tu GTPase activity in vitro, confirming apicoplast EF-Tu as kirromycin's target. Homology modelling reveals PfEF-Ts-induced structural alterations that would facilitate GDP release. Additionally, PfEF-Tu possesses chaperone-related disulphide reductase activity, providing a rationale for retention of the tufA gene on the plastid genome.\",\n      \"method\": \"Recombinant protein GTPase assay; Co-immunoprecipitation / binding interaction between recombinant PfEF-Tu and PfEF-Ts; nucleotide exchange assay; kirromycin inhibition in vitro; homology modelling; GFP-leader-sequence targeting assay for EF-Ts\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal in vitro assays (GTPase activity, nucleotide exchange, inhibitor effect, chaperone activity) plus structural modelling and localization, single lab but rigorous multi-method study\",\n      \"pmids\": [\"21163263\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Clarithromycin downregulates TUFA (PF3D7_API02900) mRNA and protein expression in P. falciparum, consistent with disruption of apicoplast translation as its mechanism of antimalarial action.\",\n      \"method\": \"qPCR for tufA mRNA; Western blotting for EF-Tu protein after clarithromycin treatment in Pf3D7 and PfK1 strains\",\n      \"journal\": \"Life sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, two related methods (qPCR + Western blot) but no mechanistic dissection of how clarithromycin affects apicoplast translation; limited controls\",\n      \"pmids\": [\"26164186\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"Phylogenetic analysis of the tufA gene from the 35-kb apicoplast genome of P. falciparum (and coccidians) grouped the organellar genome with cyanobacteria and green algal plastids, establishing the apicoplast as a secondary endosymbiotic plastid of probable green algal origin and placing tufA on the apicoplast (plastid) genome.\",\n      \"method\": \"In situ hybridization to localize the 35-kb DNA to a four-membrane organelle in Toxoplasma gondii; phylogenetic analysis of tufA gene sequences from P. falciparum, T. gondii, and E. tenella\",\n      \"journal\": \"Science (New York, N.Y.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct in situ hybridization localization of the genome plus phylogenetic analysis; replicated across multiple apicomplexan species; establishes genomic location of tufA\",\n      \"pmids\": [\"9045615\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"TUFA (PF3D7_API02900) encodes the apicoplast-genome-encoded translation elongation factor Tu (EF-Tu) of Plasmodium falciparum; it is expressed at the protein level within the apicoplast (peaking in trophozoites), hydrolyses GTP, interacts with the nuclear-encoded EF-Ts partner to catalyse GDP/GTP nucleotide exchange, possesses chaperone-related disulphide reductase activity, and is the direct molecular target of antibiotics including kirromycin, GE2270A, enacyloxin IIa, and is functionally suppressed by thiostrepton and clarithromycin.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"TUFA (PF3D7_API02900) is the apicoplast-genome-encoded translation elongation factor Tu (EF-Tu) of Plasmodium falciparum, and it functions in protein synthesis within the apicoplast, the organelle to which its protein product localizes and in which it is translated, with expression peaking in the trophozoite stage [#0, #4]. As a canonical elongation factor, recombinant PfEF-Tu hydrolyses GTP and undergoes GDP/GTP nucleotide exchange catalysed by its physical partner, the nuclear-encoded EF-Ts (PfEF-Ts), whose binding induces structural changes that would promote GDP release [#2]. Beyond its translation role, PfEF-Tu carries a chaperone-related disulphide reductase activity, a property advanced as a rationale for retention of the tufA gene on the plastid genome [#2]. TUFA is the direct molecular target of structurally distinct antibiotics: recombinant PfEF-Tu forms in vitro complexes with kirromycin, GE2270A, and enacyloxin IIa at different sites, and kirromycin inhibits its GTPase activity, while apicoplast-translation-disrupting drugs thiostrepton and clarithromycin reduce EF-Tu expression [#0, #1, #2, #3]. All of these inhibitors show antimalarial activity, marking apicoplast translation via TUFA as an antimalarial vulnerability [#1].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Establishing where tufA physically resides answered whether this elongation factor belongs to the parasite's organellar genome and clarified the evolutionary origin of that genome.\",\n      \"evidence\": \"In situ hybridization localizing the 35-kb DNA to a four-membrane organelle and phylogenetic analysis of tufA sequences across apicomplexans\",\n      \"pmids\": [\"9045615\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Does not demonstrate that the tufA-encoded protein is functional as an elongation factor\",\n        \"No evidence on protein localization or expression timing\",\n        \"No functional or drug-target data\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Identifying that recombinant PfEF-Tu binds structurally distinct antibiotics at different sites established the protein as a druggable antimalarial target, not merely a genomic feature.\",\n      \"evidence\": \"In vitro complex formation of recombinant EF-Tu with kirromycin, GE2270A, and enacyloxin IIa, plus blood-culture antimalarial assays\",\n      \"pmids\": [\"10505418\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Binding shown in vitro but effect on EF-Tu catalytic activity not measured here\",\n        \"Single lab; no structural mapping of binding sites\",\n        \"No demonstration that antimalarial activity operates through EF-Tu inhibition in vivo\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Localizing the EF-Tu protein and its stage-specific expression answered whether tufA is translated and functions inside the apicoplast, linking it to thiostrepton's site of action.\",\n      \"evidence\": \"Immunolocalization to the apicoplast, stage-specific Western blots, and EF-Tu quantification after thiostrepton treatment\",\n      \"pmids\": [\"15773980\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Reduction of EF-Tu by thiostrepton is indirect (via rRNA binding), not direct drug-EF-Tu interaction\",\n        \"Does not resolve EF-Tu catalytic mechanism\",\n        \"Single-lab evidence\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Reconstituting the catalytic cycle answered how PfEF-Tu operates enzymatically and with which partner, and confirmed kirromycin acts on its GTPase, while revealing an unexpected chaperone activity.\",\n      \"evidence\": \"Recombinant GTPase and nucleotide-exchange assays, PfEF-Tu/PfEF-Ts interaction, kirromycin inhibition in vitro, homology modelling, and GFP-leader targeting of EF-Ts\",\n      \"pmids\": [\"21163263\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural model of the EF-Tu/EF-Ts complex is homology-based, not experimentally determined\",\n        \"Physiological substrates of the disulphide reductase activity not identified\",\n        \"In vivo consequences of blocking nucleotide exchange not tested\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Testing clarithromycin's effect on TUFA expression addressed whether this macrolide's antimalarial action operates through disruption of apicoplast translation.\",\n      \"evidence\": \"qPCR and Western blotting of tufA mRNA and EF-Tu protein after clarithromycin treatment in Pf3D7 and PfK1 strains\",\n      \"pmids\": [\"26164186\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No mechanistic dissection of how clarithromycin affects apicoplast translation; limited controls\",\n        \"Downregulation may be a downstream consequence rather than a direct effect on TUFA\",\n        \"Effect on EF-Tu catalytic function not measured\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The in vivo essentiality of TUFA and the native substrates of its chaperone-related disulphide reductase activity remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No genetic knockout or conditional depletion of tufA reported in the corpus\",\n        \"No experimentally determined structure of PfEF-Tu or its complex with EF-Ts\",\n        \"Physiological targets and biological role of the disulphide reductase activity unknown\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0003746\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0005525\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0015035\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0009536\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0020011\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0006414\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"complexes\": [\n      \"PfEF-Tu / PfEF-Ts (nucleotide-exchange) complex [#2]\"\n    ],\n    \"partners\": [\n      \"PfEF-Ts (nuclear-encoded elongation factor Ts) [#2]\"\n    ],\n    \"other_free_text\": [\n      \"Direct in vitro binding target of kirromycin, GE2270A, and enacyloxin IIa at distinct sites; kirromycin inhibits its GTPase activity [#1, #2]\",\n      \"EF-Tu protein levels reduced by thiostrepton and clarithromycin, consistent with disruption of apicoplast translation [#0, #3]\",\n      \"Encoded on the 35-kb apicoplast (plastid) genome of green algal secondary-endosymbiotic origin [#4]\",\n      \"Expression peaks in the trophozoite stage of the intraerythrocytic cycle [#0]\",\n      \"Possesses chaperone-related disulphide reductase activity, offered as a rationale for retaining tufA on the plastid genome [#2]\"\n    ]\n  }\n}\n```","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_API02900","name":null,"product":"elongation factor Tu","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"TUFA","evaluation":null}