{"gene":"PBANKA_API00280","run_date":"2026-09-07T10:55:51","timeline":{"discoveries":[{"year":1997,"finding":"Phylogenetic analysis of the tufA gene (encoding elongation factor Tu) from the 35-kilobase apicoplast genomes of Toxoplasma gondii, Eimeria tenella, and Plasmodium falciparum grouped this organellar genome with cyanobacteria and green algal plastids, providing evidence that the Apicomplexa acquired a plastid by secondary endosymbiosis. This established tufA as a plastid-encoded gene in the apicomplexan lineage.","method":"Phylogenetic analysis of tufA gene sequences; in situ hybridization to localize the 35 kb DNA to a discrete four-membrane-bound organelle","journal":"Science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in situ hybridization plus phylogenetic analysis from a single study; establishes organellar localization of the gene but mechanistic detail is limited","pmids":["9045615"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2005,"finding":"The tufA gene product EF-Tu (TUFA) is translationally active within the P. falciparum apicoplast: EF-Tu protein was detected and localized to the apicoplast organelle by immunofluorescence. Expression is maximal in the trophozoite stage of the intraerythrocytic cycle. The antibiotic thiostrepton, which binds apicoplast LSU rRNA, reduced apicoplast EF-Tu protein levels, supporting translation within the apicoplast as the site of thiostrepton action.","method":"Immunofluorescence localization of EF-Tu protein to the apicoplast; Western blot quantification of EF-Tu levels after thiostrepton treatment; stage-specific expression analysis","journal":"Molecular Microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct protein localization by immunofluorescence plus drug-perturbation Western blot, single lab, two orthogonal methods","pmids":["15773980"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1999,"finding":"Recombinant P. falciparum apicoplast EF-Tu (encoded by tufA) forms demonstrable complexes in vitro with the EF-Tu inhibitors kirromycin, GE2270A, and enacyloxin IIa, which bind different sites on EF-Tu. These inhibitors also showed antimalarial activity in blood cultures, establishing TUFA/EF-Tu as a druggable translation factor target.","method":"In vitro complex formation assays between recombinant PfEF-Tu and antibiotic inhibitors; parasite growth inhibition assays in blood culture","journal":"Protist","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution of inhibitor binding to recombinant protein, single lab, two orthogonal methods (biochemical + growth inhibition)","pmids":["10505418"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2010,"finding":"Apicoplast-encoded PfEF-Tu (TUFA) hydrolyses GTP and physically interacts with its nuclear-encoded partner PfEF-Ts; PfEF-Ts mediates nucleotide exchange on PfEF-Tu (GDP release). The EF-Tu inhibitor kirromycin inhibits PfEF-Tu GTPase activity in vitro. Homology modeling of the PfEF-Tu:PfEF-Ts complex revealed structural alterations induced by PfEF-Ts that facilitate GDP release. Additionally, apicoplast EF-Tu possesses chaperone-related disulphide reductase activity, providing a rationale for retention of tufA on the plastid genome.","method":"Recombinant protein GTPase assay; in vitro kirromycin inhibition assay; co-interaction assay (EF-Tu:EF-Ts); nucleotide exchange assay; homology modeling; GFP-leader-sequence targeting assay confirming apicoplast localization of EF-Ts","journal":"International Journal for Parasitology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro enzymatic reconstitution (GTPase, nucleotide exchange, disulphide reductase), direct inhibitor assay, and structural modeling in a single study with multiple orthogonal methods","pmids":["21163263"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2015,"finding":"Clarithromycin treatment of P. falciparum downregulates tufA expression at both mRNA and protein levels, indicating disruption of apicoplast translation as part of its antimalarial mechanism of action.","method":"qPCR (tufA mRNA quantification) and Western blotting (EF-Tu protein levels) after drug treatment in Pf3D7 and PfK1 strains","journal":"Life Sciences","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single approach per measure (qPCR + Western blot), no functional rescue or mechanistic dissection beyond expression change","pmids":["26164186"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"},{"species":"Plasmodium falciparum","strain":"K1"}]}],"current_model":"PBANKA_API00280 (TUFA) encodes a plastid-genome-encoded elongation factor Tu that is translationally active within the Plasmodium apicoplast, maximally expressed in the trophozoite stage; it hydrolyses GTP, undergoes GDP/GTP exchange facilitated by its nuclear-encoded partner EF-Ts, possesses disulphide reductase (chaperone-related) activity, and is the direct molecular target of antibiotic inhibitors including kirromycin, GE2270A, enacyloxin IIa, and thiostrepton."},"narrative":{"mechanistic_narrative":"PBANKA_API00280 (TUFA) encodes a plastid-genome-encoded elongation factor Tu that functions in translation within the Plasmodium apicoplast, the relict plastid acquired by secondary endosymbiosis [PMID:9045615]. The EF-Tu protein is translationally active and localizes to the apicoplast, with maximal expression in the trophozoite stage of the intraerythrocytic cycle [PMID:15773980]. As a translation factor, TUFA/EF-Tu hydrolyses GTP and physically interacts with its nuclear-encoded partner EF-Ts, which mediates nucleotide exchange (GDP release) on EF-Tu; the protein additionally possesses chaperone-related disulphide reductase activity, offering a rationale for retention of tufA on the plastid genome [PMID:21163263]. TUFA is a validated antimalarial target: recombinant apicoplast EF-Tu forms complexes with the inhibitors kirromycin, GE2270A, and enacyloxin IIa, and kirromycin inhibits its GTPase activity in vitro [PMID:10505418, PMID:21163263]. Disruption of apicoplast translation by thiostrepton and clarithromycin reduces EF-Tu/tufA levels, linking these antibiotics' antimalarial action to this factor [PMID:15773980, PMID:26164186]. All direct evidence derives from the P. falciparum ortholog; TUFA has not been characterized in P. berghei in the available corpus.","teleology":[{"year":1997,"claim":"Established that tufA is a plastid-genome-encoded gene in Apicomplexa, defining the organellar context in which EF-Tu operates and placing the apicoplast in the cyanobacterial/plastid lineage.","evidence":"Phylogenetic analysis of tufA sequences and in situ hybridization localizing the 35 kb genome to a four-membrane organelle","pmids":["9045615"],"confidence":"Medium","gaps":["Does not demonstrate that the tufA product is expressed or functional as a protein","No biochemical characterization of EF-Tu activity","Shown in P. falciparum only"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1999,"claim":"Answered whether apicoplast EF-Tu is druggable by showing recombinant PfEF-Tu binds three distinct EF-Tu inhibitors that also inhibit parasite growth, establishing TUFA as an antimalarial translation-factor target.","evidence":"In vitro complex-formation assays between recombinant PfEF-Tu and kirromycin, GE2270A, enacyloxin IIa; blood-culture growth inhibition","pmids":["10505418"],"confidence":"Medium","gaps":["Binding shown in vitro without demonstration of the functional consequence on translation at that time","Did not confirm that growth inhibition is mediated specifically through EF-Tu in vivo","Shown in P. falciparum only"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2005,"claim":"Demonstrated that the tufA product is translationally active and organelle-resident, confirming EF-Tu operates inside the apicoplast and is stage-regulated.","evidence":"Immunofluorescence localization of EF-Tu to the apicoplast, stage-specific expression analysis, and Western blot showing thiostrepton reduces EF-Tu levels","pmids":["15773980"],"confidence":"Medium","gaps":["Correlative link to thiostrepton action rather than direct target engagement","Does not resolve the enzymatic mechanism of EF-Tu","Shown in P. falciparum only"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2010,"claim":"Resolved the biochemical mechanism of TUFA/EF-Tu, showing it is a GTPase whose nucleotide cycle is driven by its nuclear-encoded EF-Ts partner and that it carries an additional disulphide reductase (chaperone) activity, explaining plastid retention of the gene.","evidence":"Recombinant GTPase, nucleotide-exchange, and disulphide reductase assays; EF-Tu:EF-Ts interaction assay; kirromycin GTPase inhibition; homology modeling; GFP targeting of EF-Ts to apicoplast","pmids":["21163263"],"confidence":"High","gaps":["Structural model is homology-based, not an experimental structure","Physiological substrates/aminoacyl-tRNA delivery not directly reconstituted","Shown in P. falciparum only"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2015,"claim":"Extended the antibiotic-vulnerability of apicoplast translation by showing clarithromycin downregulates tufA at mRNA and protein levels, implicating this pathway in the drug's antimalarial mechanism.","evidence":"qPCR and Western blot of tufA/EF-Tu after clarithromycin treatment in Pf3D7 and PfK1 strains","pmids":["26164186"],"confidence":"Low","gaps":["Single-approach expression measurement with no functional rescue or mechanistic dissection","Does not establish whether tufA downregulation is cause or consequence of translation disruption","Shown only in P. falciparum strains 3D7 and K1"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"},{"species":"Plasmodium falciparum","strain":"K1"}]},{"year":null,"claim":"Whether the P. berghei ortholog PBANKA_API00280 itself (as opposed to the P. falciparum ortholog) is essential in vivo and whether its inhibitors act through EF-Tu genetically remains unaddressed in the corpus.","evidence":"No direct genetic or in vivo characterization of PBANKA_API00280 in the timeline","pmids":[],"confidence":"Low","gaps":["No loss-of-function or conditional knockdown data for the gene","No experimental structure of the EF-Tu:EF-Ts complex","No data specific to P. berghei"],"attribution":[]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["EF-Tu:EF-Ts complex (with nuclear-encoded apicoplast EF-Ts) [#3]"],"partners":["PFEF-TS (NUCLEAR-ENCODED NUCLEOTIDE-EXCHANGE PARTNER) [#3]"],"other_free_text":["Direct molecular target of the EF-Tu inhibitors kirromycin, GE2270A, and enacyloxin IIa [#2]","GTPase activity inhibited by kirromycin in vitro [#3]","Apicoplast EF-Tu/tufA levels reduced by thiostrepton [#1] and clarithromycin [#4]","Maximal expression in the trophozoite stage of the intraerythrocytic cycle [#1]","Plastid-genome-encoded gene in the apicomplexan lineage [#0]","All direct evidence is from the P. falciparum ortholog; PBANKA_API00280 has no P. berghei-specific characterization in the corpus"]}},"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":["Pb"],"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":8786,"output_tokens":1748,"usd":0.026289,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6802,"output_tokens":2980,"usd":0.054255,"stage2_stop_reason":"end_turn"},"total_usd":0.080544,"stage1_batch_id":"msgbatch_01DbiymDmubkPpYvdbAu5a7V","stage2_batch_id":"msgbatch_012TbrWvMRH129T7PQ4SmvrJ","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"Phylogenetic analysis of the tufA gene (encoding elongation factor Tu) from the 35-kilobase apicoplast genomes of Toxoplasma gondii, Eimeria tenella, and Plasmodium falciparum grouped this organellar genome with cyanobacteria and green algal plastids, providing evidence that the Apicomplexa acquired a plastid by secondary endosymbiosis. This established tufA as a plastid-encoded gene in the apicomplexan lineage.\",\n      \"method\": \"Phylogenetic analysis of tufA gene sequences; in situ hybridization to localize the 35 kb DNA to a discrete four-membrane-bound organelle\",\n      \"journal\": \"Science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in situ hybridization plus phylogenetic analysis from a single study; establishes organellar localization of the gene but mechanistic detail is limited\",\n      \"pmids\": [\"9045615\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"The tufA gene product EF-Tu (TUFA) is translationally active within the P. falciparum apicoplast: EF-Tu protein was detected and localized to the apicoplast organelle by immunofluorescence. Expression is maximal in the trophozoite stage of the intraerythrocytic cycle. The antibiotic thiostrepton, which binds apicoplast LSU rRNA, reduced apicoplast EF-Tu protein levels, supporting translation within the apicoplast as the site of thiostrepton action.\",\n      \"method\": \"Immunofluorescence localization of EF-Tu protein to the apicoplast; Western blot quantification of EF-Tu levels after thiostrepton treatment; stage-specific expression analysis\",\n      \"journal\": \"Molecular Microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct protein localization by immunofluorescence plus drug-perturbation Western blot, single lab, two orthogonal methods\",\n      \"pmids\": [\"15773980\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"Recombinant P. falciparum apicoplast EF-Tu (encoded by tufA) forms demonstrable complexes in vitro with the EF-Tu inhibitors kirromycin, GE2270A, and enacyloxin IIa, which bind different sites on EF-Tu. These inhibitors also showed antimalarial activity in blood cultures, establishing TUFA/EF-Tu as a druggable translation factor target.\",\n      \"method\": \"In vitro complex formation assays between recombinant PfEF-Tu and antibiotic inhibitors; parasite growth inhibition assays in blood culture\",\n      \"journal\": \"Protist\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution of inhibitor binding to recombinant protein, single lab, two orthogonal methods (biochemical + growth inhibition)\",\n      \"pmids\": [\"10505418\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Apicoplast-encoded PfEF-Tu (TUFA) hydrolyses GTP and physically interacts with its nuclear-encoded partner PfEF-Ts; PfEF-Ts mediates nucleotide exchange on PfEF-Tu (GDP release). The EF-Tu inhibitor kirromycin inhibits PfEF-Tu GTPase activity in vitro. Homology modeling of the PfEF-Tu:PfEF-Ts complex revealed structural alterations induced by PfEF-Ts that facilitate GDP release. Additionally, apicoplast EF-Tu possesses chaperone-related disulphide reductase activity, providing a rationale for retention of tufA on the plastid genome.\",\n      \"method\": \"Recombinant protein GTPase assay; in vitro kirromycin inhibition assay; co-interaction assay (EF-Tu:EF-Ts); nucleotide exchange assay; homology modeling; GFP-leader-sequence targeting assay confirming apicoplast localization of EF-Ts\",\n      \"journal\": \"International Journal for Parasitology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro enzymatic reconstitution (GTPase, nucleotide exchange, disulphide reductase), direct inhibitor assay, and structural modeling in a single study with multiple orthogonal methods\",\n      \"pmids\": [\"21163263\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Clarithromycin treatment of P. falciparum downregulates tufA expression at both mRNA and protein levels, indicating disruption of apicoplast translation as part of its antimalarial mechanism of action.\",\n      \"method\": \"qPCR (tufA mRNA quantification) and Western blotting (EF-Tu protein levels) after drug treatment in Pf3D7 and PfK1 strains\",\n      \"journal\": \"Life Sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single approach per measure (qPCR + Western blot), no functional rescue or mechanistic dissection beyond expression change\",\n      \"pmids\": [\"26164186\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"},\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"K1\"}\n      ]\n    }\n  ],\n  \"current_model\": \"PBANKA_API00280 (TUFA) encodes a plastid-genome-encoded elongation factor Tu that is translationally active within the Plasmodium apicoplast, maximally expressed in the trophozoite stage; it hydrolyses GTP, undergoes GDP/GTP exchange facilitated by its nuclear-encoded partner EF-Ts, possesses disulphide reductase (chaperone-related) activity, and is the direct molecular target of antibiotic inhibitors including kirromycin, GE2270A, enacyloxin IIa, and thiostrepton.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PBANKA_API00280 (TUFA) encodes a plastid-genome-encoded elongation factor Tu that functions in translation within the Plasmodium apicoplast, the relict plastid acquired by secondary endosymbiosis [#0]. The EF-Tu protein is translationally active and localizes to the apicoplast, with maximal expression in the trophozoite stage of the intraerythrocytic cycle [#1]. As a translation factor, TUFA/EF-Tu hydrolyses GTP and physically interacts with its nuclear-encoded partner EF-Ts, which mediates nucleotide exchange (GDP release) on EF-Tu; the protein additionally possesses chaperone-related disulphide reductase activity, offering a rationale for retention of tufA on the plastid genome [#3]. TUFA is a validated antimalarial target: recombinant apicoplast EF-Tu forms complexes with the inhibitors kirromycin, GE2270A, and enacyloxin IIa, and kirromycin inhibits its GTPase activity in vitro [#2, #3]. Disruption of apicoplast translation by thiostrepton and clarithromycin reduces EF-Tu/tufA levels, linking these antibiotics' antimalarial action to this factor [#1, #4]. All direct evidence derives from the P. falciparum ortholog; TUFA has not been characterized in P. berghei in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established that tufA is a plastid-genome-encoded gene in Apicomplexa, defining the organellar context in which EF-Tu operates and placing the apicoplast in the cyanobacterial/plastid lineage.\",\n      \"evidence\": \"Phylogenetic analysis of tufA sequences and in situ hybridization localizing the 35 kb genome to a four-membrane organelle\",\n      \"pmids\": [\"9045615\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Does not demonstrate that the tufA product is expressed or functional as a protein\",\n        \"No biochemical characterization of EF-Tu activity\",\n        \"Shown in P. falciparum only\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Answered whether apicoplast EF-Tu is druggable by showing recombinant PfEF-Tu binds three distinct EF-Tu inhibitors that also inhibit parasite growth, establishing TUFA as an antimalarial translation-factor target.\",\n      \"evidence\": \"In vitro complex-formation assays between recombinant PfEF-Tu and kirromycin, GE2270A, enacyloxin IIa; blood-culture growth inhibition\",\n      \"pmids\": [\"10505418\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Binding shown in vitro without demonstration of the functional consequence on translation at that time\",\n        \"Did not confirm that growth inhibition is mediated specifically through EF-Tu in vivo\",\n        \"Shown in P. falciparum only\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Demonstrated that the tufA product is translationally active and organelle-resident, confirming EF-Tu operates inside the apicoplast and is stage-regulated.\",\n      \"evidence\": \"Immunofluorescence localization of EF-Tu to the apicoplast, stage-specific expression analysis, and Western blot showing thiostrepton reduces EF-Tu levels\",\n      \"pmids\": [\"15773980\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Correlative link to thiostrepton action rather than direct target engagement\",\n        \"Does not resolve the enzymatic mechanism of EF-Tu\",\n        \"Shown in P. falciparum only\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Resolved the biochemical mechanism of TUFA/EF-Tu, showing it is a GTPase whose nucleotide cycle is driven by its nuclear-encoded EF-Ts partner and that it carries an additional disulphide reductase (chaperone) activity, explaining plastid retention of the gene.\",\n      \"evidence\": \"Recombinant GTPase, nucleotide-exchange, and disulphide reductase assays; EF-Tu:EF-Ts interaction assay; kirromycin GTPase inhibition; homology modeling; GFP targeting of EF-Ts to apicoplast\",\n      \"pmids\": [\"21163263\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural model is homology-based, not an experimental structure\",\n        \"Physiological substrates/aminoacyl-tRNA delivery not directly reconstituted\",\n        \"Shown in P. falciparum only\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Extended the antibiotic-vulnerability of apicoplast translation by showing clarithromycin downregulates tufA at mRNA and protein levels, implicating this pathway in the drug's antimalarial mechanism.\",\n      \"evidence\": \"qPCR and Western blot of tufA/EF-Tu after clarithromycin treatment in Pf3D7 and PfK1 strains\",\n      \"pmids\": [\"26164186\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Single-approach expression measurement with no functional rescue or mechanistic dissection\",\n        \"Does not establish whether tufA downregulation is cause or consequence of translation disruption\",\n        \"Shown only in P. falciparum strains 3D7 and K1\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"},\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"K1\"}\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether the P. berghei ortholog PBANKA_API00280 itself (as opposed to the P. falciparum ortholog) is essential in vivo and whether its inhibitors act through EF-Tu genetically remains unaddressed in the corpus.\",\n      \"evidence\": \"No direct genetic or in vivo characterization of PBANKA_API00280 in the timeline\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No loss-of-function or conditional knockdown data for the gene\",\n        \"No experimental structure of the EF-Tu:EF-Ts complex\",\n        \"No data specific to P. berghei\"\n      ],\n      \"attribution\": []\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0003746\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"GO:0005525\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0015036\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0009507\", \"supporting_discovery_ids\": [0, 1, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0006412\", \"supporting_discovery_ids\": [1, 3, 4]}\n    ],\n    \"complexes\": [\n      \"EF-Tu:EF-Ts complex (with nuclear-encoded apicoplast EF-Ts) [#3]\"\n    ],\n    \"partners\": [\n      \"PfEF-Ts (nuclear-encoded nucleotide-exchange partner) [#3]\"\n    ],\n    \"other_free_text\": [\n      \"Direct molecular target of the EF-Tu inhibitors kirromycin, GE2270A, and enacyloxin IIa [#2]\",\n      \"GTPase activity inhibited by kirromycin in vitro [#3]\",\n      \"Apicoplast EF-Tu/tufA levels reduced by thiostrepton [#1] and clarithromycin [#4]\",\n      \"Maximal expression in the trophozoite stage of the intraerythrocytic cycle [#1]\",\n      \"Plastid-genome-encoded gene in the apicomplexan lineage [#0]\",\n      \"All direct evidence is from the P. falciparum ortholog; PBANKA_API00280 has no P. berghei-specific characterization in the corpus\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"PbANKA","gene_id":"PBANKA_API00280","name":null,"product":"elongation factor Tu, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"TUFA","evaluation":null}