Final answer:
The equivalent of prokaryotic EF-G in eukaryotes is eukaryotic initiation factor 2 (eIF2), which, along with eIF2B, plays a crucial role in the initiation of protein synthesis.
Step-by-step explanation:
The eukaryotic initiation factor that is equivalent to EF-G in prokaryotes is eukaryotic initiation factor 2 (eIF2). In eukaryotes, during the initiation of protein synthesis, eIF2 forms a ternary complex with GTP and the initiator methionine tRNA (Met-tRNAi). Upon recognition of the start codon AUG on the mRNA, this ternary complex associates with the small 40S ribosomal subunit, and after binding to the 60S subunit, the GTP is hydrolyzed which causes the release of all the initiation factors and the commencement of elongation. The GTP/GDP swap on GDP-bound eIF2 is facilitated by another initiation factor, eIF2B, which is necessary for the recycling of GTP-eIF2 for subsequent rounds of initiation.