In Saccharomyces cerevisiae (Baker's yeast), SUI1 is a translation initiation factor that functions in concert with eIF-2 and the initiator tRNA-Met in directing the ribosome to the proper start site of translation [1]. SUI1 is a protein of 108 residues. Close homologs of SUI1 have been found [2] in mammals, insects and plants. SUI1 is also evolutionary related to hypothetical proteins from Escherichia coli (yciH), Haemophilus influenzae (HI1225) and Methanococcus vannielii.