Fig. 3: Pdcd4 blocks the decoding center of the 40S subunit.

A Pdcd4-NTD interacts with the universally conserved decoding bases in the A site and the P site. B Superposition with the 48S complexes in closed/Pin state (PDB:6YAL)24 showing a severe clash between mRNA and Pdcd4-NTD from the entry channel to the P-site. C Fluorescence anisotropy binding assay using a fluorescence-labeled 71-nt CAA repeat RNA, showing that Pdcd4-NTD reduces mRNA binding to the 40S. Error bars represent the mean ± SEM (n = 3). D tRNAiMet in Pin state (PDB:6YAL)24 clashes with Pdcd4-NTD, while tRNAiMet in Pout state (PDB:7A09)48 (E) does not. F Superposition of Pdcd4-NTD with the structure of either the head or body of the 43S in open/Pout state, showing a possible minor clash with eIF1A only when Pdcd4-NTD is modeled to the body.