The complete sequence of the cDNA encoding bovine mitochondrial translational initiation factor 2 (IF-2(mt)) has been obtained by library screening followed by 3'-RACE PCR. The open reading frame for bovine IF-2(mt) encodes a protein of 727 amino acids. The sequence of bovine IF-2(mt) exhibits 85% identity to human IF-2(mt), but only 38% identity to yeast IF-2(mt) and 39% identity to Escherichia coli IF-2 alpha.