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. Xavier Saelens, et al. (2001) J. Biol. Chem, 276: 41620 - 41628. Hiroyuki Kubota, et al. (2003) J. Biol. Chem , 278: 20457 - 20460. Shijian Chu, et al. (2006) Am J Physiol Lung Cell Mol Physiol , 291: L983 - L992. Eileen Connolly, et al. (2006) Mol. Cell. Biol , 26: 3955 - 3965.
