Translation initiation factor eIF3 is a multi-subunit protein complex required for initiation of protein biosynthesis in eukaryotic cells. The complex promotes ribosome dissociation, the binding of the initiator methionyl-tRNA to the 40 S ribosomal subunit, and mRNA recruitment to the ribosome. The protein product from TIF31 genes in yeast is p135 which associates with the eIF3 but does not seem to be necessary for protein translation initiation [1].

1: A 110-kilodalton subunit of translation initiation factor eIF3 and an associated 135-kilodalton protein are encoded by the Saccharomyces cerevisiae TIF32 and TIF31 genes. Vornlocher HP, Hanachi P, Ribeiro S, Hershey JW; J Biol Chem. 1999;274:16802-16812. PMID:10358023