Functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B. Kimball, S.R. (1999) Int. J. Biochem. Cell Biol. 31, 25-29. De Haro, C. et al. (1996) FASEB J. 10, 1378-1387. Sheikh, M.S. and Fornace Jr., A.J. (1999) Oncogene 18, 6121-6128. Cheshire, J.L. et al. (1999) J. Biol. Chem. 274, 4801-4806.
