eukaryotic initiation factor 2

Function

• eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP & 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 & release of an eIF-2-GDP binary complex (putative)
• in order for eIF-2 to recycle & catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B (putative)
• GTP-bound form supplies initiator methionyl-tRNA to ribosome

Structure

• heterotrimer composed of an alpha, beta & gamma chain

More general terms

• initiation factor
• guanine nucleotide regulatory protein (GNRP)
• phosphoprotein
• multisubunit protein

Additional terms

• eukaryotic initiation factor 2-gamma; eIF2-gamma (EIF2S3)
• protein synthesis initiation