In budding yeast (Saccharomyces cerevisiae), SUI1 is a translation initiationfactor that functions in concert with eIF-2 and the initiator tRNA-Met indirecting the ribosome to the proper start site of translation. SUI1 is a protein of 108 residues. Close homologues of SUI1 have been found in mammals, insects and plants. SUI1 is also evolutionary related to:Hypothetical proteins from bacteria such as Escherichia coli (yciH) or Haemophilus influenzae (HI1225).Hypothetical proteins from archaea such as Methanococcus jannaschii (MJ0463).Two eukaryotic proteins also seem to contain a C-terminal SUI1-like domain.These are:Density-regulated protein (gene: DENR). This protein is found in mammals, insects, nematodes, plants and fungi.Ligatin (gene: LGTN). This protein is found in mammals and insects.