Eukaryotic Selenocysteine Incorporation: Mechanistic Insights

Cotranslational insertion of selenocysteine occurs in both prokaryotic and eukaryotic organisms. For the most part, what is known about this process in eukaryotes has been derived from extensive analysis of the RNA requirements for selenocysteine incorporation. Studies which have defined the selenocysteine insertion sequence (SECIS) element, identified its critical sequence and structural motifs, and established constraints on its spatial relationship with the UGA selenocysteine codon, have given mechanistic insights into this critical process.