Official Full Name
eukaryotic translation initiation factor 1A, X-linked
Eukaryotic translation initiation factor 1A, X-chromosomal is a protein that in humans is encoded by the EIF1AX gene. Mammalian 17-kDa eukaryotic initiation factor, eIF1A (formerly designated eIF-4C), is essential for transfer of the initiator Met-tRNAf (as Met-tRNAf·eIF2·GTP ternary complex) to 40 S ribosomal subunits in the absence of mRNA to form the 40 S preinitiation complex (40 S·Met-tRNAf·eIF2·GTP). Furthermore, eIF1A acts catalytically in this reaction to mediate highly efficient transfer of the Met-tRNAf·eIF2·GTP ternary complex to 40 S ribosomal subunits. The 40 S complex formed is free of eIF1A which indicates that its role in 40 S preinitiation complex formation is not to stabilize the binding of Met-tRNAf to 40 S ribosomes. Additionally, the eIF1A-mediated 40 S initiation complex formed in the presence of AUG codon efficiently joins 60 S ribosomal subunits in an eIF5-dependent reaction to form a functional 80 S initiation complex. Though found in some reports, eIF1A probably plays no role either in the subunit joining reaction or in the generation of ribosomal subunits from 80 S ribosomes. The major function of eIF1A is to mediate the transfer of Met-tRNAf to 40 S ribosomal subunits to form the 40 S preinitiation complex.
EIF1AX; eukaryotic translation initiation factor 1A, X chromosome; EIF1A; EIF4C; EIF1A, EIF4C, eIF-1A, eIF-4C, EIF1AP1