PF3D7_1302800

PF3D7_1302800 (S7) is a structural component of the small (40S) subunit of the P. falciparum 80S ribosome, resolved within cryo-EM structures of the intact parasite ribosome (PMID:24913268). In this context the 40S subunit binds the translation inhibitor emetine at the E-site, where the drug blocks mRNA/tRNA translocation, sharing a binding site with pactamycin (PMID:24913268). The 40S subunit that contains S7 is present in stage-specific ribosome variants across the parasite life cycle (PMID:37053161) and has been captured in actively translating, elongation-factor-bound states inside infected erythrocytes by in situ cryo-electron tomography (PMID:40825879). Beyond its membership in the 40S small subunit and the structural roles inferred from that context, no experiment in the available corpus has individually characterized the molecular function or interactions of PF3D7_1302800 itself.

1. 2014 Medium

   Establishing the atomic architecture of the P. falciparum ribosome placed S7 within the 40S small subunit and defined the E-site as the binding pocket where emetine arrests mRNA/tRNA translocation, framing the subunit as an antimalarial drug target.

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

   PMID:24913268

   Open questions at the time

   • PF3D7_1302800 is not individually interrogated; its specific contacts and function within the subunit are not resolved
   • No direct evidence that S7 itself contacts the emetine-binding E-site
   • No functional assay tying S7 to translocation
2. 2023 Low

   Comparative analysis of ribosome composition across life-cycle stages raised the question of whether the parasite deploys distinct ribosome variants, implicating 40S proteins including S7 as components of stage-specific assemblies.

   Evidence Structural and comparative genomic analysis of ribosome heterogeneity across P. falciparum life-cycle stages

   PMID:37053161

   Open questions at the time

   • Abstract-level evidence only; no mechanistic data specific to PF3D7_1302800
   • Whether S7 itself varies between stage-specific variants is not shown
   • Functional consequence of any heterogeneity for S7 is unaddressed
3. 2025 Medium

   Resolving native ribosomes inside infected erythrocytes established the structural context of the 40S subunit during active elongation and showed that a Plasmodium-specific inhibitor shifts the balance of translating versus biogenesis states.

   Evidence In situ cryo-electron tomography of P. falciparum-infected erythrocytes yielding eight high-resolution translating-ribosome structures

   PMID:40825879

   Open questions at the time

   • S7 is not individually interrogated; findings pertain to the whole ribosome
   • No S7-specific role in the elongation-to-biogenesis shift is demonstrated

• Whether PF3D7_1302800 has any function, interaction, or phenotype distinct from its structural membership in the 40S subunit remains uncharacterized.
• No genetic knockdown/knockout of S7 reported
• No S7-specific interaction partners beyond the 40S subunit identified
• No assembly or extraribosomal function tested