InterPro domain: IPR017334

Eukaryotic translation initiation factor 3 subunit G (eIF3g) is a component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is involved in protein synthesis and, together with other initiation factors, stimulates binding of mRNA and methionyl-tRNAi to the 40S ribosome [ 1 , 2 ]. eIF3g can bind 18S rRNA [ 3 ].

In Drosophila spp. there are two G subunits, known as G-1 and G2.

At least eleven different protein factors are involved in initiation of protein synthesis in eukaryotes. Binding of initiator tRNA and mRNA to the 40S subunit requires the presence of the translation initiation factors eIF-2 and eIF-3, with eIF-3 being particularly important for 80S ribosome dissociation and mRNA binding [ 4 ]. eIF-3 is the most complex translation inititation factor, consisting of about 13 putative subunits and having a molecular weight of between 550 - 700kDa in mammalian cells. Subunits are designated eIF-3a - eIF-3m; the large number of subunits means that the interactions between the individual subunits that make up the eIF-3 complex are complex and varied [ 5 ]. Subunit G is required for eIF3 integrity.

1. Conservation and diversity of eukaryotic translation initiation factor eIF3. J. Biol. Chem. 272, 1101-9
2. PCI proteins eIF3e and eIF3m define distinct translation initiation factor 3 complexes. BMC Biol. 3, 14
3. Characterization of the p33 subunit of eukaryotic translation initiation factor-3 from Saccharomyces cerevisiae. J. Biol. Chem. 274, 8546-53
4. Eukaryotic initiation factors eIF-2 and eIF-3: interactions, structure and localization in ribosomal initiation complexes. Biochimie 73, 1007-19