Eukaryotic Translation Initiation Factor 4G3 (EIF4G3)

EIF4G3 encodes a protein that functions in translation by aiding the assembly of the ribosome onto the messenger RNA template. Confusingly, this protein is usually referred to as eIF4GII, as although EIF4G3 is the third gene that is similar to eukaryotic translation initiation factor 4 gamma, the second isoform EIF4G2 is not an active translation initiation factor.

The predicted 1,585-amino acid eIF4GII protein is 46% identical to eIF4GI. On Western blots, both eIF4G proteins migrated at approximately 220 kD. Far Western analysis and coimmunoprecipitation experiments demonstrated that eIF4GII directly interacts with eIF4E, eIF4A, and eIF3.