The 700-kD eukaryotic translation initiation factor-3 (eIF3) is the largest eIF and contains at least 12 subunits, including EIF2S12. eIF3 plays an essential role in translation by binding directly to the 40S ribosomal subunit and promoting formation of the 40S preinitiation complex.
encodes a 218-amino acid protein composed of approximately 10% leucine residues. In vitro transcription/translation of EIF3S12 resulted in labeled protein that comigrated with the 28-kD protein found in eIF3 complex. Northern blot analysis detected ubiquitous expression of a 1.1-kb EIF3S12 transcript in human cell lines and tissues, with highest levels in brain, testis, and kidney.