Protein synthesis in eukaryotic organisms is a complex process that requires cooperation among a large number of polypeptides including ribosomal proteins, modification of enzymes, and ribosome-associated translation factors. The initiation phase of protein synthesis, during which ribosomes select mRNAs to be translated and identify the translational start site, requires a set of eIFs (eukaryotic Translation Initiation Factors), many of which are comprised of multiple polypeptide subunits. eIF2 (Eukaryotic Initiation Factor-2) is a GTP (Guanosine Triphosphate)-binding protein that escorts the initiation-specific form of Met-tRNA (Met-tRNAi) onto the ribosome. It is composed of 3 non-identical subunits, alpha (36 kD), beta (38 kD), and gamma (52 kD). cDNAs for each of the subunits have been cloned and sequenced from a variety of species, [...]