PF3D7_1341200

PF3D7_1341200 (L18) is a structural constituent of the 60S large subunit of the Plasmodium falciparum 80S cytoplasmic ribosome, identified within the large subunit in multiple high-resolution cryo-EM structures of the intact ribosome (PMID:24913268, PMID:26432834). It is present in ribosomes purified from blood-stage schizonts (PMID:26432834) and in native, actively translating ribosomes imaged in situ inside infected human erythrocytes by cryo-electron tomography (PMID:40825879). Beyond its membership in the 60S subunit as resolved in these whole-ribosome structures, no experiment in the available corpus has specifically interrogated the function, interactions, or modifications of L18 itself; the structures that establish its position also identified antimalarial drug-binding sites (emetine, mefloquine) on the ribosome, but these bind other regions of the large subunit rather than L18 (PMID:24913268, PMID:28288098). The corpus establishes nothing about PF3D7_1341200 beyond its role as a component of the 60S ribosomal large subunit.

1. 2014 Medium

   Establishing the architecture of the P. falciparum 80S ribosome placed L18 within the resolved 60S large subunit, defining its identity as a structural ribosomal protein of the parasite.

   Evidence Cryo-EM structure of the P. falciparum 80S ribosome at 3.2 Å with emetine bound

   PMID:24913268

   Open questions at the time

   • No functional experiment interrogates L18 independently of the ribosome complex
   • No specific interactions or modifications of L18 defined
   • Drug-binding characterized for the ribosome, not for L18
2. 2015 Medium

   Multiple cryo-EM reconstructions of schizont-derived ribosomes confirmed L18 as a stable 60S component and distinguished parasite ribosome features from mammalian ribosomes, relevant for selective targeting.

   Evidence Five sub-nanometer cryo-EM reconstructions with flexible-fitting atomic models from blood-stage schizont ribosomes

   PMID:26432834

   Open questions at the time

   • L18-specific structural or sequence divergence from mammalian counterpart not isolated
   • No functional assay of L18
   • Role of L18 in translation dynamics not tested
3. 2017 Medium

   A drug-bound ribosome structure validated the 60S subunit as an antimalarial target while incidentally confirming L18 membership, without implicating L18 in the drug-binding mechanism.

   Evidence Cryo-EM at 3.2 Å of the ribosome bound to (+)-mefloquine, with mutagenesis of binding-site residues and parasite growth assays

   PMID:28288098

   Open questions at the time

   • Mefloquine binds the GTPase-associated centre, not L18
   • No evidence L18 contributes to drug binding or resistance
   • L18 function untested
4. 2025 Medium

   In-cell structural imaging placed L18 within native, actively translating ribosomes, confirming it participates in functional ribosomes under physiological conditions rather than only in purified preparations.

   Evidence In situ cryo-electron tomography of eight translating ribosome states inside infected human erythrocytes, with a Plasmodium-specific translation inhibitor

   PMID:40825879

   Open questions at the time

   • L18-specific behavior across translation states not resolved
   • No perturbation of L18 to test its functional contribution
   • L18 role in ribosome biogenesis response not addressed

• Whether L18 has any function, interaction, or modification beyond serving as a structural 60S component remains entirely uncharacterized in the available corpus.
• No genetic knockout or knockdown of L18
• No L18-specific interaction or modification mapping
• No assay separating L18 from the intact ribosome complex