{"gene":"PF3D7_0211400","run_date":"2026-09-07T10:55:51","timeline":{"discoveries":[{"year":1998,"finding":"KASIII (PF3D7_0211400) bears an N-terminal presequence consistent with apicoplast targeting, and the gene shows high similarity to plastid homologues, implicating it in fatty acid biosynthesis within the apicoplast organelle of P. falciparum.","method":"Sequence analysis and immunolocalization of the related ACP protein to the apicoplast; thiolactomycin inhibition of P. falciparum growth used as functional evidence for the pathway","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization shown for ACP (not KASIII itself), sequence-based inference for KASIII apicoplast targeting; inhibitor evidence supports pathway essentiality but does not directly characterize KASIII mechanism","pmids":["9770490"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2002,"finding":"Recombinant KASIII (PF3D7_0211400) from P. falciparum is soluble and catalytically active in a truncated form; holo-PfACP is a substrate for the transacylase activity of KASIII; substitution of the active-site cysteine to alanine or serine abolishes enzymatic activity, identifying this cysteine as essential for catalysis.","method":"Recombinant protein expression, in vitro enzymatic activity assays, active-site mutagenesis (Cys→Ala and Cys→Ser)","journal":"Molecular and biochemical parasitology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro enzymatic reconstitution combined with active-site mutagenesis in a single study, directly demonstrating catalytic mechanism","pmids":["12270624"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2003,"finding":"KASIII (PF3D7_0211400) catalyzes the decarboxylative condensation of malonyl-pfACP with acyl-CoA substrates (initiating step of type II fatty acid biosynthesis): it uses acetyl-CoA (kcat 230 min−1, KM 17.9 µM) and butyryl-CoA (kcat 200 min−1, KM 35.7 µM) efficiently, whereas isobutyryl-CoA is a poor substrate (13-fold less activity). KASIII also catalyzes an acyl-CoA:ACP transacylase (ACAT) reaction ~700-fold slower than the KAS condensation reaction. KASIII shows little preference for malonyl-pfACP over E. coli malonyl-ACP as the acyl acceptor. Thiolactomycin does not inhibit KASIII (IC50 >330 µM), but three 1,2-dithiole-3-one compounds inhibit it with IC50 values of 0.53–10.4 µM and also inhibit P. falciparum growth in culture.","method":"Recombinant protein expression and purification, in vitro kinetic characterization, substrate specificity assays, inhibitor IC50 determination, parasite growth inhibition assay","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — detailed in vitro kinetic reconstitution with multiple substrates, inhibitor assays, and culture confirmation; replicated functional characterization across two independent studies (PMID 12270624 and 12549938)","pmids":["12549938"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2003,"finding":"KASIII (PF3D7_0211400) uses malonyl-pfACP (produced by pfMCAT from malonyl-CoA and pfACP) as its acyl-acceptor substrate in the initiating condensation step; the transit-peptide-containing precursor form pfACP(trans) is NOT a substrate for pfMCAT, indicating the mature form of ACP is required for the KASIII reaction.","method":"Reconstituted in vitro two-step reaction: pfMCAT malonyl transfer followed by pfKASIII condensation assay using purified recombinant proteins","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — biochemical reconstitution with purified components defining the functional substrate relationship between pfMCAT, pfACP, and KASIII in a single rigorous study","pmids":["12549938"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2005,"finding":"Several thiolactomycin analogues inhibit KASIII (PF3D7_0211400) enzymatic activity in vitro with improved potency relative to thiolactomycin itself; however, inhibition of KASIII activity does not correlate clearly with inhibition of parasite growth for all compound series, leading to the conclusion that KASIII is not the primary target of these TLM analogues in the parasite.","method":"Recombinant KASIII enzyme inhibition assay, P. falciparum growth inhibition assay, structure-activity relationship analysis","journal":"Journal of medicinal chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct enzymatic inhibition assay on recombinant KASIII combined with parasite growth assay, single lab; negative conclusion (not primary TLM target) is the main mechanistic finding","pmids":["16161997"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"KASIII (PF3D7_0211400) is an apicoplast-targeted beta-ketoacyl-ACP synthase III in P. falciparum that catalyzes the initiating decarboxylative condensation of malonyl-pfACP with acyl-CoA primers (preferring acetyl-CoA and butyryl-CoA) in the type II fatty acid biosynthesis pathway, with an essential active-site cysteine required for catalysis; it also performs a slow acyl-CoA:ACP transacylase reaction, is not inhibited by thiolactomycin, but is inhibited by 1,2-dithiole-3-one compounds that also block parasite growth."},"narrative":{"mechanistic_narrative":"KASIII (PF3D7_0211400) is a beta-ketoacyl-ACP synthase III that catalyzes the initiating decarboxylative condensation step of type II fatty acid biosynthesis in the P. falciparum apicoplast, an organelle targeting inferred from its N-terminal presequence and homology to plastid enzymes [PMID:9770490]. In reconstituted reactions, KASIII condenses malonyl-pfACP with short-chain acyl-CoA primers, using acetyl-CoA and butyryl-CoA efficiently but isobutyryl-CoA poorly, and its acyl-acceptor substrate malonyl-pfACP is supplied by pfMCAT acting on the mature (transit-peptide-cleaved) form of pfACP [PMID:12549938]. An active-site cysteine is essential for catalysis, since Cys→Ala or Cys→Ser substitution abolishes activity; the enzyme additionally performs a slow acyl-CoA:ACP transacylase reaction (~700-fold slower than condensation) [PMID:12270624, PMID:12549938]. Pharmacologically, KASIII is not inhibited by thiolactomycin but is inhibited by 1,2-dithiole-3-one compounds that also block parasite growth, whereas thiolactomycin analogues inhibit the enzyme without a clear correlation to growth inhibition, indicating KASIII is not the primary parasite target of those analogues [PMID:12549938, PMID:16161997].","teleology":[{"year":1998,"claim":"Establishing where KASIII acts addressed whether P. falciparum harbors a plastid-like fatty acid pathway, placing the enzyme in the apicoplast as a candidate drug target.","evidence":"Sequence analysis and apicoplast localization of the related ACP protein, with thiolactomycin growth inhibition as pathway evidence","pmids":["9770490"],"confidence":"Medium","gaps":["Apicoplast targeting of KASIII itself was inferred from presequence, not directly imaged","No direct enzymatic characterization of KASIII in this study"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2002,"claim":"Recombinant reconstitution and active-site mutagenesis answered whether KASIII is a genuine catalytic enzyme and identified the residue required for catalysis.","evidence":"Recombinant expression of a truncated active enzyme, in vitro activity assays, and Cys→Ala/Cys→Ser active-site mutagenesis","pmids":["12270624"],"confidence":"High","gaps":["Full substrate specificity and kinetics not resolved here","Transacylase versus condensation activities not quantitatively separated"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2003,"claim":"Detailed kinetics and reconstitution defined the reaction KASIII catalyzes, its acyl-CoA primer preferences, and the source of its acyl-acceptor substrate, establishing its role as the pathway-initiating condensing enzyme.","evidence":"In vitro kinetic characterization across acyl-CoA substrates, a reconstituted pfMCAT-to-KASIII two-step assay, and inhibitor IC50 determinations with parasite growth assays","pmids":["12549938"],"confidence":"High","gaps":["In vitro kinetics do not establish physiological flux or in vivo substrate identity","Little discrimination between pfACP and E. coli ACP leaves acceptor specificity determinants unclear"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2005,"claim":"Testing thiolactomycin analogues clarified whether KASIII is the parasite target of these inhibitors, concluding it is not the primary target despite in vitro inhibition.","evidence":"Recombinant KASIII inhibition assays, parasite growth inhibition assays, and structure-activity analysis","pmids":["16161997"],"confidence":"Medium","gaps":["The actual parasite target of the TLM analogues is not identified","Lack of enzyme-growth correlation is not mechanistically explained"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"Whether KASIII is genetically essential for blood-stage parasite survival and what its validated small-molecule vulnerability is remain open.","evidence":"","pmids":[],"confidence":"Low","gaps":["No genetic knockout/knockdown phenotype for KASIII in the corpus","No structural model of KASIII reported","Direct apicoplast localization of KASIII protein not demonstrated"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":["PFACP (MALONYL-PFACP ACYL-ACCEPTOR SUBSTRATE)","PFMCAT (GENERATES MALONYL-PFACP SUBSTRATE UPSTREAM OF KASIII)"],"other_free_text":["Substrate preference: acetyl-CoA and butyryl-CoA efficient primers; isobutyryl-CoA poor substrate [#2]","Active-site cysteine essential for catalysis (Cys→Ala/Ser abolishes activity) [#1, #2]","Not inhibited by thiolactomycin (IC50 >330 µM) but inhibited by 1,2-dithiole-3-one compounds (IC50 0.53–10.4 µM) that also block parasite growth [#2]","Thiolactomycin analogues inhibit the enzyme but KASIII is judged not the primary parasite target [#4]","Mature (transit-peptide-cleaved) ACP required; precursor pfACP(trans) is not a pfMCAT substrate [#3]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"9770490","id":"PMC_9770490","title":"Nuclear-encoded proteins target to the plastid in Toxoplasma gondii and Plasmodium falciparum.","date":"1998","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9770490","citation_count":600,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["beta-ketoacyl-ACP synthase III","ACP"],"competing_organism_flag":true,"competing_organism_match":"Toxoplasma","competing_organism_only":false},{"pmid":"11738814","id":"PMC_11738814","title":"Deciphering apicoplast targeting signals--feature extraction from nuclear-encoded precursors of Plasmodium falciparum apicoplast 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acid biosynthesis.","date":"2004","source":"Planta medica","url":"https://pubmed.ncbi.nlm.nih.gov/15326547","citation_count":90,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"12930838","id":"PMC_12930838","title":"Identification, characterization, and inhibition of Plasmodium falciparum beta-hydroxyacyl-acyl carrier protein dehydratase (FabZ).","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12930838","citation_count":88,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"12549938","id":"PMC_12549938","title":"The initiating steps of a type II fatty acid synthase in Plasmodium falciparum are catalyzed by pfACP, pfMCAT, and pfKASIII.","date":"2003","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12549938","citation_count":75,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["KASIII","beta-ketoacyl-ACP synthase III","ACP","PfACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"17522044","id":"PMC_17522044","title":"In vivo functional analyses of the type II acyl carrier proteins of fatty acid biosynthesis.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17522044","citation_count":66,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"19143588","id":"PMC_19143588","title":"GFP-targeting allows visualization of the apicoplast throughout the life cycle of live malaria parasites.","date":"2009","source":"Biology of the 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ACPs.","date":"2006","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16734426","citation_count":61,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP","PfACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"19768685","id":"PMC_19768685","title":"Plasmodium falciparum acyl carrier protein crystal structures in disulfide-linked and reduced states and their prevalence during blood stage growth.","date":"2010","source":"Proteins","url":"https://pubmed.ncbi.nlm.nih.gov/19768685","citation_count":60,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP","PfACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"12906873","id":"PMC_12906873","title":"Apicoplast fatty acid biosynthesis as a target for medical intervention in apicomplexan parasites.","date":"2003","source":"International journal for 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Synthesis.","date":"2026","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/41959251","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42537022","id":"PMC_42537022","title":"In Silico Exploration of Antimalarial Potential of Ethanolic Leaf Extract of Heliotropium indicum.","date":"2026","source":"Nigerian journal of physiological sciences : official publication of the Physiological Society of Nigeria","url":"https://pubmed.ncbi.nlm.nih.gov/42537022","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40893585","id":"PMC_40893585","title":"Computational elucidation of Plasmodium falciparum enoyl-ACP reductase inhibition by Salacia debilis compounds: adaptive ligand binding drives antimalarial activity.","date":"2025","source":"In silico pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40893585","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41393793","id":"PMC_41393793","title":"Network pharmacology, molecular docking and molecular dynamics simulation suggest CE-326597 as an antimalarial molecule.","date":"2025","source":"In silico pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/41393793","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["ACP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"38826533","id":"PMC_38826533","title":"Exploring Novel Antimalarial Compounds Targeting Plasmodium falciparum Enoyl-ACP Reductase: Computational and Experimental 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apicoplast organelle of P. falciparum.\",\n      \"method\": \"Sequence analysis and immunolocalization of the related ACP protein to the apicoplast; thiolactomycin inhibition of P. falciparum growth used as functional evidence for the pathway\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization shown for ACP (not KASIII itself), sequence-based inference for KASIII apicoplast targeting; inhibitor evidence supports pathway essentiality but does not directly characterize KASIII mechanism\",\n      \"pmids\": [\"9770490\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Recombinant KASIII (PF3D7_0211400) from P. falciparum is soluble and catalytically active in a truncated form; holo-PfACP is a substrate for the transacylase activity of KASIII; substitution of the active-site cysteine to alanine or serine abolishes enzymatic activity, identifying this cysteine as essential for catalysis.\",\n      \"method\": \"Recombinant protein expression, in vitro enzymatic activity assays, active-site mutagenesis (Cys→Ala and Cys→Ser)\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro enzymatic reconstitution combined with active-site mutagenesis in a single study, directly demonstrating catalytic mechanism\",\n      \"pmids\": [\"12270624\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"KASIII (PF3D7_0211400) catalyzes the decarboxylative condensation of malonyl-pfACP with acyl-CoA substrates (initiating step of type II fatty acid biosynthesis): it uses acetyl-CoA (kcat 230 min−1, KM 17.9 µM) and butyryl-CoA (kcat 200 min−1, KM 35.7 µM) efficiently, whereas isobutyryl-CoA is a poor substrate (13-fold less activity). KASIII also catalyzes an acyl-CoA:ACP transacylase (ACAT) reaction ~700-fold slower than the KAS condensation reaction. KASIII shows little preference for malonyl-pfACP over E. coli malonyl-ACP as the acyl acceptor. Thiolactomycin does not inhibit KASIII (IC50 >330 µM), but three 1,2-dithiole-3-one compounds inhibit it with IC50 values of 0.53–10.4 µM and also inhibit P. falciparum growth in culture.\",\n      \"method\": \"Recombinant protein expression and purification, in vitro kinetic characterization, substrate specificity assays, inhibitor IC50 determination, parasite growth inhibition assay\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — detailed in vitro kinetic reconstitution with multiple substrates, inhibitor assays, and culture confirmation; replicated functional characterization across two independent studies (PMID 12270624 and 12549938)\",\n      \"pmids\": [\"12549938\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"KASIII (PF3D7_0211400) uses malonyl-pfACP (produced by pfMCAT from malonyl-CoA and pfACP) as its acyl-acceptor substrate in the initiating condensation step; the transit-peptide-containing precursor form pfACP(trans) is NOT a substrate for pfMCAT, indicating the mature form of ACP is required for the KASIII reaction.\",\n      \"method\": \"Reconstituted in vitro two-step reaction: pfMCAT malonyl transfer followed by pfKASIII condensation assay using purified recombinant proteins\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — biochemical reconstitution with purified components defining the functional substrate relationship between pfMCAT, pfACP, and KASIII in a single rigorous study\",\n      \"pmids\": [\"12549938\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Several thiolactomycin analogues inhibit KASIII (PF3D7_0211400) enzymatic activity in vitro with improved potency relative to thiolactomycin itself; however, inhibition of KASIII activity does not correlate clearly with inhibition of parasite growth for all compound series, leading to the conclusion that KASIII is not the primary target of these TLM analogues in the parasite.\",\n      \"method\": \"Recombinant KASIII enzyme inhibition assay, P. falciparum growth inhibition assay, structure-activity relationship analysis\",\n      \"journal\": \"Journal of medicinal chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct enzymatic inhibition assay on recombinant KASIII combined with parasite growth assay, single lab; negative conclusion (not primary TLM target) is the main mechanistic finding\",\n      \"pmids\": [\"16161997\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"KASIII (PF3D7_0211400) is an apicoplast-targeted beta-ketoacyl-ACP synthase III in P. falciparum that catalyzes the initiating decarboxylative condensation of malonyl-pfACP with acyl-CoA primers (preferring acetyl-CoA and butyryl-CoA) in the type II fatty acid biosynthesis pathway, with an essential active-site cysteine required for catalysis; it also performs a slow acyl-CoA:ACP transacylase reaction, is not inhibited by thiolactomycin, but is inhibited by 1,2-dithiole-3-one compounds that also block parasite growth.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"KASIII (PF3D7_0211400) is a beta-ketoacyl-ACP synthase III that catalyzes the initiating decarboxylative condensation step of type II fatty acid biosynthesis in the P. falciparum apicoplast, an organelle targeting inferred from its N-terminal presequence and homology to plastid enzymes [#0]. In reconstituted reactions, KASIII condenses malonyl-pfACP with short-chain acyl-CoA primers, using acetyl-CoA and butyryl-CoA efficiently but isobutyryl-CoA poorly, and its acyl-acceptor substrate malonyl-pfACP is supplied by pfMCAT acting on the mature (transit-peptide-cleaved) form of pfACP [#2, #3]. An active-site cysteine is essential for catalysis, since Cys\\u2192Ala or Cys\\u2192Ser substitution abolishes activity; the enzyme additionally performs a slow acyl-CoA:ACP transacylase reaction (~700-fold slower than condensation) [#1, #2]. Pharmacologically, KASIII is not inhibited by thiolactomycin but is inhibited by 1,2-dithiole-3-one compounds that also block parasite growth, whereas thiolactomycin analogues inhibit the enzyme without a clear correlation to growth inhibition, indicating KASIII is not the primary parasite target of those analogues [#2, #4].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Establishing where KASIII acts addressed whether P. falciparum harbors a plastid-like fatty acid pathway, placing the enzyme in the apicoplast as a candidate drug target.\",\n      \"evidence\": \"Sequence analysis and apicoplast localization of the related ACP protein, with thiolactomycin growth inhibition as pathway evidence\",\n      \"pmids\": [\"9770490\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Apicoplast targeting of KASIII itself was inferred from presequence, not directly imaged\",\n        \"No direct enzymatic characterization of KASIII in this study\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Recombinant reconstitution and active-site mutagenesis answered whether KASIII is a genuine catalytic enzyme and identified the residue required for catalysis.\",\n      \"evidence\": \"Recombinant expression of a truncated active enzyme, in vitro activity assays, and Cys\\u2192Ala/Cys\\u2192Ser active-site mutagenesis\",\n      \"pmids\": [\"12270624\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Full substrate specificity and kinetics not resolved here\",\n        \"Transacylase versus condensation activities not quantitatively separated\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Detailed kinetics and reconstitution defined the reaction KASIII catalyzes, its acyl-CoA primer preferences, and the source of its acyl-acceptor substrate, establishing its role as the pathway-initiating condensing enzyme.\",\n      \"evidence\": \"In vitro kinetic characterization across acyl-CoA substrates, a reconstituted pfMCAT-to-KASIII two-step assay, and inhibitor IC50 determinations with parasite growth assays\",\n      \"pmids\": [\"12549938\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"In vitro kinetics do not establish physiological flux or in vivo substrate identity\",\n        \"Little discrimination between pfACP and E. coli ACP leaves acceptor specificity determinants unclear\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Testing thiolactomycin analogues clarified whether KASIII is the parasite target of these inhibitors, concluding it is not the primary target despite in vitro inhibition.\",\n      \"evidence\": \"Recombinant KASIII inhibition assays, parasite growth inhibition assays, and structure-activity analysis\",\n      \"pmids\": [\"16161997\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The actual parasite target of the TLM analogues is not identified\",\n        \"Lack of enzyme-growth correlation is not mechanistically explained\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether KASIII is genetically essential for blood-stage parasite survival and what its validated small-molecule vulnerability is remain open.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No genetic knockout/knockdown phenotype for KASIII in the corpus\",\n        \"No structural model of KASIII reported\",\n        \"Direct apicoplast localization of KASIII protein not demonstrated\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0033818\", \"supporting_discovery_ids\": [1, 2, 3]},\n      {\"term_id\": \"GO:0016747\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0020011\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0006633\", \"supporting_discovery_ids\": [0, 2, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"pfACP (malonyl-pfACP acyl-acceptor substrate)\",\n      \"pfMCAT (generates malonyl-pfACP substrate upstream of KASIII)\"\n    ],\n    \"other_free_text\": [\n      \"Substrate preference: acetyl-CoA and butyryl-CoA efficient primers; isobutyryl-CoA poor substrate [#2]\",\n      \"Active-site cysteine essential for catalysis (Cys\\u2192Ala/Ser abolishes activity) [#1, #2]\",\n      \"Not inhibited by thiolactomycin (IC50 >330 \\u00b5M) but inhibited by 1,2-dithiole-3-one compounds (IC50 0.53\\u201310.4 \\u00b5M) that also block parasite growth [#2]\",\n      \"Thiolactomycin analogues inhibit the enzyme but KASIII is judged not the primary parasite target [#4]\",\n      \"Mature (transit-peptide-cleaved) ACP required; precursor pfACP(trans) is not a pfMCAT substrate [#3]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0211400","name":null,"product":"beta-ketoacyl-ACP synthase III","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0308200","name":null,"product":"apicoplast beta-ketoacyl-acyl carrier protein synthase III precursor, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0409900","name":null,"product":"beta-ketoacyl-acyl carrier protein synthase III precursor, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"KASIII","evaluation":null}