PF3D7_0719600

PF3D7_0719600 (L11a) is a structural component of the large (60S) subunit of the Plasmodium falciparum cytoplasmic 80S ribosome, established by successive cryo-EM structures of the purified ribosome (PMID:24913268, PMID:26432834) and confirmed in the native context of actively translating ribosomes inside infected human erythrocytes by in situ cryo-electron tomography (PMID:40825879). Within these structures the 80S ribosome harbors a druggable GTPase-associated centre on the large subunit that serves as the mefloquine binding site, though this drug-binding role is attributed to the large subunit as a whole rather than to L11a specifically (PMID:28288098). Beyond its membership in the 60S subunit as resolved by these structural studies, no specific enzymatic activity, binding partner, post-translational modification, or individual functional role has been mechanistically established for L11a itself in the available corpus.

1. 2014 Medium

   Whether L11a is a bona fide constituent of the P. falciparum ribosome was first answered by resolving it within a high-resolution structure of the assembled 80S ribosome, placing it in the large (60S) subunit.

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

   PMID:24913268

   Open questions at the time

   • L11a is resolved only as part of the complex and is not individually isolated or functionally validated
   • No enzymatic activity or specific binding partner assigned to L11a itself
2. 2015 Medium

   The assignment of L11a to the 60S subunit was corroborated across multiple ribosome conformations purified from blood-stage parasites, strengthening its status as a stable structural component.

   Evidence Five cryo-EM reconstructions with flexibly fitted atomic models from schizont-purified ribosomes

   PMID:26432834

   Open questions at the time

   • L11a not characterized beyond complex membership
   • No stage-specific or functional role distinguished for L11a
3. 2017 Medium

   Placing L11a within a structure that also mapped the antimalarial mefloquine binding site clarified that the druggable GTPase-associated centre lies on the large subunit, but did not attribute this drug interaction to L11a itself.

   Evidence Cryo-EM structure at 3.2 Å with mutagenesis of ribosome-binding residues to confirm the mefloquine mechanism

   PMID:28288098

   Open questions at the time

   • Drug binding is a property of the large subunit, not demonstrated to involve L11a specifically
   • No direct L11a-mefloquine contact established
4. 2025 Medium

   Whether L11a occupies the same position in functioning ribosomes in vivo was addressed by visualizing native, actively translating 80S ribosomes inside infected erythrocytes, confirming L11a in its cellular context during elongation.

   Evidence In situ cryo-electron tomography of P. falciparum-infected human erythrocytes yielding eight ribosome structures in translating elongation states

   PMID:40825879

   Open questions at the time

   • L11a is resolved only as a ribosomal component, not individually characterized
   • No functional contribution of L11a to elongation dynamics isolated

• No experiment in the available corpus assigns L11a an individual molecular activity, binding partner, post-translational modification, or non-structural function distinct from its membership in the 60S subunit.
• No genetic or biochemical dissection of L11a-specific function
• No interaction partners beyond the ribosome established for L11a
• No post-translational modification or regulatory role characterized