Eukaryotic Elongation Factor, Selenocysteine tRNA Specific (EEFSEC)

Decoding of UGA selenocysteine (sec) codons in eubacteria is mediated by the specialized elongation factor SelB, which conveys the charged tRNA(sec) to the A site of the ribosome, through binding to the sec insertion sequence (SECIS) mRNA hairpin. By searching an EST database for SelB homologs, followed by 5-prime RACE and screening a HeLa cell cDNA library, Fagegaltier et al. (2000) obtained a partial human cDNA encoding SELB.

Using the partial human sequence for further EST database searching, they identified a full-length cDNA encoding mouse SelB. The deduced 583-amino acid mouse SelB protein and the partial 526-amino acid human SELB protein share 88% amino acid identity.