The crystal structure of the eukaryotic 40S ribosomal subunit in complex with eIF1 and eIF1A

Eukaryotic translation initiation factors (eIFs) 1A and 1 are central players in the complex process of start-codon recognition. To improve mechanistic understanding of this process, we determined the crystal structure of the 40S ribosomal subunit in complex with eIF1A and eIF1 from Tetrahymena thermophila at a resolution of 3.7 angstrom. It reveals the positions of the two factors on the 40S and the conformational changes that accompany their binding.