Translation initiation in eukaryotes necessitates the assembly of an 80S ribosomal
complex containing methionyl initiator tRNA (Met-tRNAiMet), which is
base paired at the initiation codon (AUG, GUG) in eligible transcripts. Eukaryotic
initiation factors (eIFs) are utilized in a sequence of reactions that leads
to 80S ribosomal assembly and initiation of translation. Eukaryotic initiation
factor 3 (eIF3) is the largest family of eIFs and consists of at least 12 unique
subunits in mammals. eIFε, also known as eIF p47, binds to the 40S ribosome
and promotes the binding of methionyl-tRNAi and mRNA and associates with
the complex p170-eIF3.